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1
Ababutain, Ibtisam. "Antimicrobial Activity and Gas Chromatography-Mass Spectrometry (GC-MS) Analysis of Saudi Arabian Ocimum basilicum Leaves Extracts". Journal of Pure and Applied Microbiology 13, n. 2 (30 giugno 2019): 823–33. http://dx.doi.org/10.22207/jpam.13.2.17.
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IWASA, Shuichi, Shigeki OHIGASHI, Toshio KOSAKI, Yukiko SHIMIZU, Kazunori KOMATSUZAKI, Masafumi HASHINO, Hiroshi SAITO e Takumi YANAIHARA. "19-Hydroxyandrostenedione in Human Ovarian Vein Measured by GC-MS". Folia Endocrinologica Japonica 67, n. 6 (1991): 692–701. http://dx.doi.org/10.1507/endocrine1927.67.6_692.
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Jordáková, I., J. Dobiáš, M. Voldich e J. Poustka. "Determination of vinyl chloride monomer in food contact materials by solid phase microextraction coupled with gas chromatography/mass spectrometry". Czech Journal of Food Sciences 21, No. 1 (18 novembre 2011): 13–17. http://dx.doi.org/10.17221/3472-cjfs.
Abstract (sommario):
The present study concerns the optimisation of the headspace solid phase microextraction (HS/SPME) combined with gas chromatography/mass spectrometry (GC/MS) for the vinyl chloride monomer determination. Samples of PVC materials were analysed using the Carboxen/Polydimethylsiloxane (CX/PDMS) 75 µm fibre. For this fibre, the achieved limit of detection was 0.05 µg/kg, and that of quantification 0.17 µg/kg, respectively, with RSD 5%. The levels of VCM found ranged from 0.29 to 0.44 mg/kg, in the case of foil, the VCM content determined was 3.65 mg/kg which means that the maximal limit allowed was exceeded.
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Aisiyah, Adella, Ajeng Nita Aryani, Diva Rizqi Salsabilla, Putri Mutiara Iskandar e Silvana Lestari Irwansyah. "Identifikasi Senyawa Mdma dan Paracetamol dalam Sampel Urine Menggunakan Metode Kromatografi Lapis Tipis dan Kromatografi Gas – Spektrofotometri Massa (Gc-Ms)". Jurnal Health Sains 3, n. 5 (24 maggio 2022): 690–96. http://dx.doi.org/10.46799/jhs.v3i5.482.
Abstract (sommario):
MDMA (3,4-methylenedioximet amphetamine) is a semisynthetic compound derived from stimulant type amphetamine (ATS) which works by triggering the release of serotonin. Paracetamol (acetaminophen) is one type of drug that has an analgesic-antipyretic effect. MDMA analysis requires a relatively fast method, so the TLC method was chosen. The identification test was carried out using 3 chromatographic systems, namely methanol: ammonia TA (100:1.5 v/v), methanol: butanol TAF (60:40 v/v), and Toluene: acetone: ethanol: ammonia TAEA (45: 45: 7: 3v/v/v/v). The determination test was carried out using the TAEA system and MDMA was used as a standard. The results of the identification test showed that the sample contained MDMA through the Hrfc and spectrum approaches. Qualitative Analysis of Paracetamol Compounds (Acetaminophen) in Urine aims to analyze paracetamol compounds (acetaminophen) in urine qualitatively by using gas chromatography - mass spectrometry (GC-MS). Extraction of paracetamol in urine samples was carried out using ethyl acetate, which was then derivatized using BSTFA containing 1% TMCS and analyzed using gas chromatography – mass spectrometry (GC-MS). The results showed that urine samples at 1, 2, and 3 hours after consuming paracetamol gave positive results for acetaminophen-TMS while at 24, 168, and 720 hours after consumption they were negative.
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Timkovsky, J., A. W. H. Chan, T. Dorst, A. H. Goldstein, B. Oyama e R. Holzinger. "Organic aerosol composition measurements with advanced offline and in-situ techniques during the CalNex campaign". Atmospheric Measurement Techniques Discussions 7, n. 12 (12 dicembre 2014): 12449–80. http://dx.doi.org/10.5194/amtd-7-12449-2014.
Abstract (sommario):
Abstract. Our understanding of formation processes, physical properties and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in-situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS). 153 compounds were identified using the GC×GC/TOF-MS, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC×GC/TOF-MS signal (sum of 123 compounds). A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m−3 using the GC×GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60%). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC×GC/TOF-MS) than those suggested by in-situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.
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Timkovsky, J., A. W. H. Chan, T. Dorst, A. H. Goldstein, B. Oyama e R. Holzinger. "Comparison of advanced offline and in situ techniques of organic aerosol composition measurement during the CalNex campaign". Atmospheric Measurement Techniques 8, n. 12 (10 dicembre 2015): 5177–87. http://dx.doi.org/10.5194/amt-8-5177-2015.
Abstract (sommario):
Abstract. Our understanding of formation processes, physical properties, and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC × GC/TOF-MS). Using the GC × GC/TOF-MS 153 compounds were identified, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC × GC/TOF-MS signal (sum of 123 compounds) for the Los Angeles area. A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m−3 using the GC × GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60 %). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC × GC/TOF-MS) than those suggested by in situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.
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Salah, Eldeen A. Ali. "Assessment of Cucumber and Paper Contamination by Pesticides Residues in Khartoum State using Quechers Method and Gas Liquid Chromatography-Mass Spectrometry". Food Science & Nutrition Technology 5, n. 3 (12 maggio 2020): 1–6. http://dx.doi.org/10.23880/fsnt-16000220.
Abstract (sommario):
In this paper, we present the investigation of 30 pesticides in total of 138 samples of different fresh cucumber and paper from central markets in Khartoum state using the quick easy cheap effective rugged and safe (QuEChERS) multi-residue extraction, followed by gas chromatography-mass spectrometry (GC-MS). Pesticide residues were not detected in 68 samples (49.3%), while 70 samples (50.7%) contained detectable amount of pesticide residues. The percentages of contaminated vegetable samples are 69.4%, 47.2%, 38.9% and 30% for cucumber, sweet paper, green paper and armenian cucumber respectively. Multiple pesticides residues were detected on 6 samples with percentage of (4.3%) from total analyzed samples. Multiple residues with two pesticides were present in 2 and 4 samples of cucumber and sweet paper. Seven pesticides diazinon, cypermethrin, lamdacyhalothrin, dimethoate, pendimethalin, malathion and tetramethrin were detected in the analyzed vegetable samples with concentration range between 0.013-0.652 mg/kg and mean range between 0.0222-0.1927mg/kg of contaminated samples. It is necessary continuous monitoring of pesticide use on vegetables. Summer season was the highly contaminated with pesticides.
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Kim, Jin Hyo, Jong Min Park, Geun-Hyoung Choi, Yun-Ki Park, Geon-Jae Im, Doo-Ho Kim e Oh-Kyung Kwon. "Comparison of Liquid Chromatography-Mass/Mass Spectrometry (MS) and Gas Chromatography-MS for Quantitative Analysis of Indole-3-acetic acid and Indole-3-butyric acid from the Concentrated Liquid Fertilizer". Journal of Applied Biological Chemistry 56, n. 1 (31 marzo 2013): 53–57. http://dx.doi.org/10.3839/jabc.2013.010.
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Delgado-Chavero, C. L., E. Zapata-Márquez, J. M. García-Casco e A. Paredes-Torronteras. "Statistical model for classifying the feeding systems of Iberian pigs through Gas Chromatography (GC-FID) and Isotope Ratio Mass Spectrometry (GC-C-IRMS)". Grasas y Aceites 64, n. 2 (10 aprile 2013): 157–65. http://dx.doi.org/10.3989/gya.130412.
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Fay, Laurent B., e Andreas A. Staempfli. "New Approach to Processing of Gas Chromatographic/Mass Spectrometric Data for Detection of Off Flavors in Complex Mixtures". Journal of AOAC INTERNATIONAL 78, n. 6 (1 novembre 1995): 1429–34. http://dx.doi.org/10.1093/jaoac/78.6.1429.
Abstract (sommario):
Abstract Chemical compounds responsible for off flavors in foodstuffs are often difficult to identify because of their low levels in complex matrixes. A simple method is described to detect and identify off flavor compounds by gas chromatographic/mass spectrometric (GC/MS) analysis and data processing for sorting the GC/MS files in 14-ion series. The 14 homologous-ion series correspond to the sum of the intensities of the ions, x + (CH2)n, where x varies from 1 to 14 and n varies from 1 to ∞, allowing to cover the whole acquired mass range. Processing of the ion series allows automatic screening of all acquired masses. We use this method routinely in our laboratory to find compounds responsible for a contamination. It is a powerful tool for off flavor identification by comparison between a reference and a contaminated sample. The method can be used with any type of data system and any chromatographic instrument coupled to a mass spectrometer.
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Berliana Aprida, Cantika Dewi, Erlangga Muhamad Prayuda, Febry Nola Odhia, Nadia Andriani, Putri Setya Tyasna, Regita Nailuvar e Syifa Dwi Andini. "Analisis Senyawa Acetaminophen pada Spesimen Rambut Manusia Menggunakan Metode Kromatografi Gas-Spektrometri Massa (Gc-Ms)". Syntax Idea 4, n. 5 (20 maggio 2022): 861–70. http://dx.doi.org/10.46799/syntax-idea.v4i5.1835.
Abstract (sommario):
Paracetamol is a drug containing non opiod analgesics and non-steroidal antipyretics (AINS). This journal review aims to analyze and find out the content of paracetamol (acetaminophen) can be detected in biological samples of the hair of a patient undergoing paracetamol treatment therapy using the gas chromatography-Mass spectrometry (GC-MS) method and knowing how much influence hair length has on paracetamol (acetaminophen) concentrations. Biological samples of human hair were obtained by two different methods, from volunteers and 10 patients taking paracetamol. Paracetamol in human hair is extracted using methanol, then the extraction results are privatized with BSTFA content mixed with 1% TMCS and the last stage is analyzed using the gas chromatography method-Mass spectrometry (GC-MS). The results showed that patients who had taken paracetamol showed that in their hair samples detected positive acetaminophen in the form of acetaminophen-TMS. The acetaminophen-TMS form is produced as a result of derivatization with BSTFA containing 1% TMCS. In the hair sample with a length of 0-3 cm obtained concentrations of 0.1761-0.3392 ng / mg hair samples, in hair samples with a length of 0-6 cm obtained concentrations of 0.2081-0.4845 ng / mg hair samples and in hair samples with a length of 0-10 cm obtained a concentration of 0.2473-0.5782 ng / mg hair samples. From this journal review shows acetaminophen compounds can be detected in human hair specimens in individuals undergoing acetaminophen therapy, then in derivatization treatment can optimize the results of acetaminophen analysis in hair specimens and on the length of human hair can affect the concentration of acetaminophen compounds with the GC-MS method.
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Hotmian, Ellen, Elly Suoth, Fatimawali Fatimawali e Trina Tallei. "ANALISIS GC-MS (GAS CHROMATOGRAPHY - MASS SPECTROMETRY) EKSTRAK METANOL DARI UMBI RUMPUT TEKI (Cyperus rotundus L.)". PHARMACON 10, n. 2 (17 maggio 2021): 849. http://dx.doi.org/10.35799/pha.10.2021.34034.
Abstract (sommario):
ABSTRACTThe Nut Grass Tuber (Cyperus rotundus L.) is a plant that is believed by the public to cure several diseases. According to a study conducted in vivo and in vitro, the extract the tuber root has many potentials such as anticancer, anti-inflammatory, antibacterial, etc. This study aims to determine the polar bioactive compounds contained in the bulb tubers. The method used was the extraction of nut tuber dry powder using methanol as a solvent by maceration process and then analyzed using gas chromatography - mass spectrometry (GC-MS) to obtain information on the content of the tubers The results of GC-MS analysis from this study indicate that there are 177 possible components of the compound extracted using methanol. The results also showed that there were three possible polar bioactive compounds at the highest peak of the GC-MS analysis, namely 7-Isopropenyl-1,4a-dimethyl-4,4a, 5,6, 7,8-hexahydro-3H-naphthalen-2-one, 1 (2H) -Naphthalenone, 3,4,4a, 5,6,7-hexahydro-4a, 5-dimethyl-3- (1-methylethenyl) -, [3S- (3a, 4aa, 5a)] -, and 2 (1H) Naphthalenone, 3,5,6,7,8,8a-hexahydro-4,8a-dimethyl-6- (1-methylethenyl) -.Keywords : Methanolic extract, nut grass tuber, Cyperus rotundus L., GC-MS ABSTRAKUmbi Rumput Teki (Cyperus rotundus L.) merupakan tumbuhan yang dipercayai masyarakat dapat menyembuhkan beberapa penyakit. Menurut sebuah penelitian yang dilakukan secara in vivo maupun in vitro, kandungan ekstrak umbi rumput teki memiliki banyak potensi seperti antikanker, antiinflamasi, antibakteri, dll. Penelitian ini bertujuan untuk mengetahui senyawa-senyawa bioaktif polar yang terkandung pada umbi rumput teki. Metode yang digunakan yaitu ekstraksi serbuk kering umbi rumput teki menggunakan pelarut metanol dengan proses maserasi kemudian dianalisis menggunakan kromatografi gas – spektrometri massa (GC-MS) untuk mendapatkan informasi kandungan dalam umbi rumput teki. Hasil analisis GC-MS dari penelitian ini menunjukkan bahwa terdapat 177 kemungkinan komponen senyawa yang diekstraksi menggunakan pelarut methanol. Hasil penelitian juga menunjukkan bahwa terdapat tiga kemungkinan senyawa bioaktif polar pada puncak tertinggi hasil analisis GC-MS, yaitu 7-Isopropenyl-1,4a-dimethyl-4,4a,5,6,7,8-hexahydro-3H-naphthalen-2-one, 1(2H)-Naphthalenone, 3,4,4a,5,6,7-hexahydro-4a,5-dimethyl-3-(1-methylethenyl)-, [3S-(3a,4aa,5a)]-, dan 2(1H)Naphthalenone, 3,5,6,7,8,8a-hexahydro-4,8a-dimethyl-6-(1-methylethenyl)-. Kata kunci : Ekstrak metanol, umbi rumput teki, Cyperus rotundus L., GC-MS
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Mohammed Al bratty, Mohammed Al bratty, Neelaveni Thangavel Neelaveni Thangavel, Hassan Ahmad Alhazmi Hassan Ahmad Alhazmi, Asim Najmi Asim Najmi, Amani Ali Jebril Shar Amani Ali Jebril Shar, Bshoor Ali Farhan Alhabsi Bshoor Ali Farhan Alhabsi, Sumaiya Mosa Suliman Ghazwani Sumaiya Mosa Suliman Ghazwani, Safeena Eranhiyil Ashraf Safeena Eranhiyil Ashraf e Ziaur Rehman Ziaur Rehman. "Gas Chromatography-Mass Spectrometry-based Phytochemical Analysis and In-Vitro Anti-Lipid Peroxidation, Cyclooxygenase Inhibition Activities of Saudi Eruca sativa Leaves". Journal of the chemical society of pakistan 44, n. 2 (2022): 175. http://dx.doi.org/10.52568/001001/jcsp/44.02.2022.
Abstract (sommario):
Eruca sativa is a wholesome yearly shrubbery herb in Saudi Arabia. Eruca sativa leaves are a conventional food and are consumed raw in salads. The present research reports the phytochemical analysis, in-vitro anti-lipid peroxidation, total anti-oxidant capability, cyclooxygenase-1, and -2 (COX1 and COX2) inhibition activities of Saudi Eruca sativa leaves water decoction (EWD). Gas chromatography-mass spectrometry (GC-MS) of EWD revealed seventeen constituents of six different chemical groups: phenolics (23.60%), aromatic and aliphatic esters (16.97%), terpenoids (31.91%), heterocyclics (14.83%), sulfur containing organics (11.25%), and silyl compounds (1.44%). The presence of Astaxanthin (1.96%), Clionasterol (12.81%), Ingol-12-acetate (4.77%), and Phytol (12.37%) in EWD indicated that the decoction technique was effective in extracting thermostable terpenoids. This research is the first report on Eruca sativa unraveling the thermostable phytochemicals. The EWD exhibited a straight-line relationship between liver lipid peroxidation inhibition and 150 to 400 μg/ml concentrations. The % anti-lipid peroxidation effect produced by EWD and Quercetin was statistically significant. At the highest 400 μg/ml dose, EWD exhibits 68.46 and#177; 0.01% anti-lipid peroxidation activity. The demonstrated IC50 of EWD and Ascorbic acid concerning the total anti-oxidant capability is 217.90 μg/ml and 74.91 μg/ml. The in-vitro assay protocols delineated the modes of inhibition of the biological oxidation processes by Eruca sativa, indicating transfer of hydrogen ion and metal ions reduction. The COX inhibitory potential was screened using Ellmannand#39;s reagent. The IC50 values for COX1 and COX2 inhibitions were 152.31μg/ml and 146.4 μg/ml, respectively, indicating that EWD has a potent COX inhibitory potential compared to Indomethacin. The COX2/COX1 ratio of inhibition, less than one, suggested that EWD phytochemicals would be preferential inhibitors of COX2. The current investigation justifies Eruca sativa leaves as a beneficial health food by establishing the chemical composition of water decoction that contributed to the anti-oxidant and COX inhibition activity.
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Primpke, Sebastian, Marten Fischer, Claudia Lorenz, Gunnar Gerdts e Barbara M. Scholz-Böttcher. "Comparison of pyrolysis gas chromatography/mass spectrometry and hyperspectral FTIR imaging spectroscopy for the analysis of microplastics". Analytical and Bioanalytical Chemistry 412, n. 30 (26 ottobre 2020): 8283–98. http://dx.doi.org/10.1007/s00216-020-02979-w.
Abstract (sommario):
AbstractAnalysis of microplastics (MP) in environmental samples is an emerging field, which is performed with various methods and instruments based either on spectroscopy or thermoanalytical methods. In general, both approaches result in two different types of data sets that are either mass or particle number related. Depending on detection limits of the respective method and instrumentation the derived polymer composition trends may vary. In this study, we compare the results of hyperspectral Fourier-transform infrared (FTIR) imaging analysis and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) analysis performed on a set of environmental samples that differ in complexity and degree of microplastic contamination. The measurements were conducted consecutively, and on exactly the same sample. First, the samples were investigated with FTIR using aluminum oxide filters; subsequently, these were crushed, transferred to glass fiber filters, in pyrolysis cups, and measured via Py-GC/MS. After a general data harmonization step, the trends in MP contamination were thoroughly investigated with regard to the respective sample set and the derived polymer compositions. While the overall trends in MP contamination were very similar, differences were observed in the polymer compositions. Furthermore, polymer masses were empirically calculated from FTIR data and compared with the Py-GC/MS results. Here, a most plausible shape-related overestimation of the calculated polymer masses was observed in samples with larger particles and increased particle numbers. Taking into account the different measurement principles of both methods, all results were examined and discussed, and future needs for harmonization of intermethodological results were identified and highlighted.
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Antasionasti, Irma, Sri Sudewi, Imam Jayanto e Jainer Pasca Siampa. "MEKANISME REAKSI FRAGMENTASI SENYAWA KIMIA DALAM KULIT BUAH ALPUKAT (Persea americana Mill.)". Jurnal Farmasi Medica/Pharmacy Medical Journal (PMJ) 2, n. 2 (2 dicembre 2019): 61. http://dx.doi.org/10.35799/pmj.2.2.2019.26528.
Abstract (sommario):
ABSTRACTInvestigation of the fragment structure of ions and fragmentation reaction is crucial and needs to be done to reconstruct the chemical structure of the examined sample. Therefore, it is necessary to study the fragmentation mechanisms of chemical compound that identified from avocado peel to study the rules of the fragmentation reaction that occurs Sample analysis was examined using Gas Chromatography-Mass Spectrometry (GC-MS) with ionization Electron Impact (EI). Two compounds foun in avocado peel are 1,2,4-trihidroksiheptadek-12,16-diyne and 1,2,4-trihidroksiheptadek-16-yne-18-ene following the principle of even electron positive (EE+) which tends to always form even electron positive (EE+) and even electron neutral (EE0). The fragmentation mechanisms in both compounds are σ bond dissociation reaction and i cleavage which forms even electron positive (EE+) and even electron neutral (EE0). The fragmentation mechanism of the compounds in avocado peel can be estimated through interpretation of GC-MS mass spectra with base peak m/z 87. Keywords : Persea americana Mill.; GC-MS; fragmentation; 1,2,4-trihidroksiheptadek-12,16-diyne; 1,2,4-trihidroksiheptadek-16-yne-18-ene ABSTRAKPenyidikan struktur ion-ion fragment serta reaksi fragmentasinya sangat penting dan perlu dilakukan untuk dapat merekonstruksi kembali struktur kimia sampel yang diperiksa. Oleh karena itu, perlu diketahui mekanisme fragmentasi senyawa kimia yang diidentifikasi dari sampel kulit buah alpukat untuk mengetahui kaidah reaksi fragmentasi yang terjadi. Analisis sampel dilakukan menggunakan Gas-Chromatography-Mass Spectrometry (GC-MS) dengan cara ionisasi Electron Impact (EI). Dua senyawa yang terkandung dalam kulit buah alpukat yaitu senyawa 1,2,4-trihidroksiheptadek-12,16-diena dan senyawa 1,2,4-trihidroksiheptadek-16-ena-18-una mengikuti kaidah fragmentasi ion elektron genap positif (EE+) cenderung untuk selalu membentuk ion elektron genap positif (EE+) dan molekul elektron genap netral (EE0). Mekanisme fragmentasi pada kedua senyawa tersebut terjadi melalui reaksi dissosiasi ikatan σ dan reaksi pemutusan induktif membentuk ion elektron genap positif (EE+) dan molekul elektron genap netral (EE0). Mekanisme fragmentasi senyawa dalam kulit buah alpukat dapat diperkirakan melalui interpretasi spektrum massa GC-MS dengan base peak m/z 87. Kata kunci: Persea americana Mill.; GC-MS; fragmentasi; 1,2,4-trihidroksiheptadek-12,16-diena; 1,2,4-trihidroksiheptadek-16-ena-18-una
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Rosenblatt, J., D. Chinkes, M. Wolfe e R. R. Wolfe. "Stable isotope tracer analysis by GC-MS, including quantification of isotopomer effects". American Journal of Physiology-Endocrinology and Metabolism 263, n. 3 (1 settembre 1992): E584—E596. http://dx.doi.org/10.1152/ajpendo.1992.263.3.e584.
Abstract (sommario):
In metabolic tracer studies it is frequently useful to infuse tracers that are differently labeled variants of the same molecule. These tracers are known as isotopomers. Analysis of the enrichment of each isotopic analogue can be accomplished by gas chromatography-mass spectrometry (GC-MS). However, the raw GC-MS data must be corrected to give the information required. This paper addresses how to transform the raw GC-MS data, consisting of relative abundance ratios at specific ion masses, into relative molar ratios of tracer and tracee molecules. Several correction factors are necessary. First, the background must be measured and corrected for, since it is always present in the sample. Second, the abundances in the spectrum of the labeled molecule are different from those in the unlabeled molecule, and this proportionality "skew" is corrected. A third correction factor accounts for the overlapping spectra of two or more isotopomers that cannot be measured independently. The final correction removes the "double vision" effect that may appear in some spectra due to the presence of (M - H)+ species.
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Shafigullina, Zulfiya R., Ludmila I. Velikanova, Natalia V. Vorokhobina, Ekaterina V. Malevanaya, Elena G. Strelnikova, Vagan Yu Bokhian, Timur A. Britvin e Ivan S. Stilidi. "Specific characteristics of metabolomics as assessed by gas chromatography-mass spectrometry in patients with adrenocortical cancer and with adrenal incidentalomas in congenital adrenal hyperplasia". Almanac of Clinical Medicine 50, n. 1 (28 aprile 2022): 38–46. http://dx.doi.org/10.18786/2072-0505-2022-50-007.
Abstract (sommario):
Background: Prolonged episodes of uncontrolled congenital adrenal hyperplasia (CAH) have been shown to result in the occurrence of secondary adrenal neoplasms. Prevalence of adrenal incidentalomas in the patients with 21-hydroxylase deficiency ranges from 11% to 82%. As assessed by gas chromatography-mass spectrometry (GC-MS), patients with adrenocortical cancer (ACC) have increased level of steroid hormone precursors due to decreased activity of adrenal steroidogenesis enzymes, mainly that of 21-hydroxylase and 11-hydroxylase. It seems relevant to compare the specific characteristics of steroid metabolism by GC-MS in ACC patients and in patients with adrenal incidentalomas and CAH associated with 21-hydroxylase deficiency (21-OHD).
Aim: To identify (by GC-MS) common abnormalities in steroid metabolism and differential diagnostic biomarkers in ACC patients and CAH patients with 21-OHD and adrenal masses.
Materials and methods: The study included 41 patients with adrenal cortex neoplasms aged 18 to 65 years without clinical and laboratory signs of endogenous hypercortisolism. Twenty three (23) patients had non-metastatic ACC and 18 patients had CAH due to 21-OHD. The control group included 26 healthy blood donors aged 20 to 59 years. Urine steroid profiles were measured by GC-MS with a gas chromatograph-mass spectrometer (Shimadzu GCMS-QP2020).
Results: In the ACC patients, there was an increase in urinary excretion of tetrahydro-11-deoxycortisol, dehydroepiandrosterone, androstenediol-17, etiocholanolone, pregnenediol, and 3,16,20-pregnenetriol (3,16,20-dP3), as well as a decrease in the 3,16,20-dP3/3,16,20-dP3 ratio, compared to the values in the patients with CAH due to 21-OHD. Compared to the healthy control, 21-hydroxylase, 11-hydroxylase, 5-reductase and 11-hydroxysteroid-dehydrogenase (11-HSDH) type 2 activities were lower. Compared to the ACC patients, those with CAH due to 21-OHD had higher urinary excretion of 11-oxo-pregnanetriol (11-oxo-P3) and 21-deoxy-tetrahydrocortisol and lower 5-THF+5-THF+THE)/11-oxo-P3 ratio of 9.0, determination of 11-oxo-dP3, signs higher 5-reductase activity and lower 11-HSDH type 1 activity. The ACC patients and the patients with CAH due to 21-OHD had common abnormalities of steroid metabolism, such as lower activities of 21-hydroxylase, 3-hydroxysteroid-dehydrogenase and 11-hydroxylase, and no differences in urinary excretion of a number of ACC biomarkers (androgens, pregnanediol, and 5-ene-pregnenes).
Conclusion: The assessment of urinary excretion of androgens, progestagens, and glucocorticoids by GC-MS made it possible to identify common abnormalities in steroid metabolism in the patients with ACC and CAH due to 21-OHD, which confirms the role of disordered steroidogenesis in the formation of adrenocortical tumors.
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Hornsby, K. E., M. J. Flynn, J. R. Dorsey, M. W. Gallagher, R. Chance, C. E. Jones e L. J. Carpenter. "A Relaxed Eddy Accumulation (REA)-GC/MS system for the determination of halocarbon fluxes". Atmospheric Measurement Techniques Discussions 2, n. 2 (30 marzo 2009): 951–80. http://dx.doi.org/10.5194/amtd-2-951-2009.
Abstract (sommario):
Abstract. Very short lived halocarbons (VSLH) play an important role in the transport of halogen atoms to the troposphere and lower stratosphere. Here we describe the development of a relaxed eddy accumulation system using gas chromatography coupled to a mass spectrometer (REA-GC/MS) to determine surface fluxes of VSLH with a time resolution of about 0.5 h. Laboratory tests showed that use of a common inlet for upward, downward and deadband flow paths resulted in mixing of upward and downward moving air masses, therefore we recommend the use of separate inlets. The modified system underwent field trials at Mace Head on the west coast of Ireland, where there are dense kelp beds known to emit a range of halocarbons. Over a 16 h period in mid-September 2007, the mean fluxes obtained were 51.7±5.9, 2.9±0.4 and 0.9±0.1 nmol m−2 day−1 for CH2Br2, CH2ICl and CH2IBr, respectively.
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Hornsby, K. E., M. J. Flynn, J. R. Dorsey, M. W. Gallagher, R. Chance, C. E. Jones e L. J. Carpenter. "A Relaxed Eddy Accumulation (REA)-GC/MS system for the determination of halocarbon fluxes". Atmospheric Measurement Techniques 2, n. 2 (7 agosto 2009): 437–48. http://dx.doi.org/10.5194/amt-2-437-2009.
Abstract (sommario):
Abstract. Very short lived halocarbons (VSLH) play an important role in the transport of halogen atoms to the troposphere and lower stratosphere. Here we describe the development of a relaxed eddy accumulation system using gas chromatography coupled to a mass spectrometer (REA-GC/MS) to determine surface fluxes of VSLH with a time resolution of about 0.5 h. Laboratory tests showed that use of a common inlet for upward, downward and deadband flow paths resulted in mixing of upward and downward moving air masses, therefore we recommend the use of separate inlets. The modified system underwent field trials at Mace Head on the west coast of Ireland, where there are dense kelp beds known to emit a range of halocarbons. Over a 16 h period in mid-September 2007, the mean fluxes obtained were 16.1±1.8, 4.0±0.54 and 1.2±0.2 nmol m−2 day−1 for CH2Br2 CH2ICl and CH2IBr, respectively.
20
Gao, Yaqin, Hongli Wang, Lingling Yuan, Shengao Jing, Bin Yuan, Guofeng Shen, Liang Zhu et al. "Measurement report: Underestimated reactive organic gases from residential combustion – insights from a near-complete speciation". Atmospheric Chemistry and Physics 23, n. 12 (19 giugno 2023): 6633–46. http://dx.doi.org/10.5194/acp-23-6633-2023.
Abstract (sommario):
Abstract. Reactive organic gases (ROGs), as important precursors of secondary pollutants, are not well resolved as their chemical complexity has challenged their quantification in many studies. Here, a near-complete speciation of ROG emissions from residential combustion was developed by the combination of proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) with a gas chromatography system equipped with a mass spectrometer and a flame ionization detector (GC-MS/FID), including 1049 species in all. Among them, 125 identified species, ∼ 90 % of the total ROG masses, were applied to evaluate their emission characteristics through real combustion samplings in rural households of China. The study revealed that with 55 species, mainly oxygenated species, higher hydrocarbons with ≥8 carbon atoms, and nitrogen-containing species, previously un- and under-characterized, ROG emissions from residential coal and biomass combustion were underestimated by 44.3 % ± 11.8 % and 22.7 % ± 3.9 %, respectively, which further amplified the underestimation of secondary organic aerosol formation potential (SOAP) as high as 70.3 % ± 1.6 % and 89.2 % ± 1.0 %, respectively. The hydroxyl radical reactivity (OHR) of ROG emissions was also undervalued significantly. The study provided a feasible method for the near-complete speciation of ROGs in the atmosphere and highlighted the importance of acquiring completely speciated measurement of ROGs from residential emissions, as well as other processes.
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Stettin, Daniel, e Georg Pohnert. "MSdeCIpher: A Tool to Link Data from Complementary Ionization Techniques in High-Resolution GC-MS to Identify Molecular Ions". Metabolites 14, n. 1 (22 dicembre 2023): 10. http://dx.doi.org/10.3390/metabo14010010.
Abstract (sommario):
Electron ionization (EI) and molecular ion-generating techniques like chemical ionization (CI) are complementary ionization methods in gas chromatography (GC)-mass spectrometry (MS). However, manual curation effort and expert knowledge are required to correctly assign molecular ions to fragment spectra. MSdeCIpher is a software tool that enables the combination of two separate datasets from fragment-rich spectra, like EI-spectra, and soft ionization spectra containing molecular ion candidates. Using high-resolution GC-MS data, it identifies and assigns molecular ions based on retention time matching, user-defined adduct/neutral loss criteria, and sum formula matching. To our knowledge, no other freely available or vendor tool is currently capable of combining fragment-rich and soft ionization datasets in this manner. The tool’s performance was evaluated on three test datasets. When molecular ions are present, MSdeCIpher consistently ranks the correct molecular ion for each fragment spectrum in one of the top positions, with average ranks of 1.5, 1, and 1.2 in the three datasets, respectively. MSdeCIpher effectively reduces candidate molecular ions for each fragment spectrum and thus enables the usage of compound identification tools that require molecular masses as input. It paves the way towards rapid annotations in untargeted analysis with high-resolution GC-MS.
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Cordero, Maribel, Henry Borbón, Félix R. Román, Luis Morell, Rigoberto Víquez, Luis R. Villegas, Roy Soto e Ilena Vega. "CARACTERIZACIÓN QUÍMICA Y FUNCIONAL DE METABOLITOS ANTIMICROBIANOS AISLADOS DE ASCIDIAN RHOPALAEA BIRKELANDI". Revista Ciencias Marinas y Costeras 3 (31 dicembre 2011): 111. http://dx.doi.org/10.15359/revmar.3.9.
Abstract (sommario):
Marine ecosystems have a very large diversity of resources, most of them still partially unknown, and a few others exploited for development of new industrial and toxicological products. The objective of this investigation was to determine whether the acetone extract of the ascidia R. birkelandi from the Pacific coast of Costa Rica showed qualitative antimicrobial activity against the S. aureus bacteria and the G. candidum fungus, and to verify their main secondary metabolites in the active extract using chromatographic and spectroscopic techniques. Ascidians were collected at Tambor, Guanacaste, Costa Rica, between December 2007 and March 2008. Activity against the Gram positive bacteria and fungi was evaluated using ethanolic (95%) and acetonic extracts. Both extracts showed activity against G. candidum; however, only the acetonic extract showed activity against S. aureus. A coumarin and a hydroxyanthraquinone were isolated from a crude extract of R. birkelandi as metabolites present in the active fraction. Purification and isolation were performed by chromatographic techniques and solid phase extraction. Structural information was obtained by spectroscopic analyses: Ultraviolet (UV-Visible), Fourier Transform Infrared (FT-IR), Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS), Gas Chromatography Mass Spectrometry (GC/MS), Proton Nuclear Magnetic Resonance (1HNMR), and Carbon-13 Magnetic Resonance (13C-NMR). Further studies are recommended for characterization and quantification of the active components of this extract and the possible elucidation of the mechanisms of action. Los ecosistemas marinos poseen una gran cantidad de recursos, muchos de ellos todavía desconocidos y muy pocos de ellos explotados para el desarrollo de nuevos productos industriales y toxicológicos. Los objetivos de esta investigación fueron determinar si el extracto acetónico de la ascidia R. birkelandi de la costa pacífica de Costa Rica presenta actividad antimicrobial cualitativa contra la bacteria S. aureus y el hongo G. candidum, y determinar por técnicas cromatográficas y espectroscópicas los metabolitos secundarios principales presentes en el extracto activo. Se recolectó la ascidia en la zona de Tambor en la provincia de Guanacaste, Costa Rica, entre los meses de diciembre del 2007 y marzo del 2008. Se realizaron extractos crudos en acetona y etanol al 95% para evaluar la actividad contra una bacteria Gram positiva y un hongo. Ambos extractos presentaron actividad contra G. candidum, pero solo el extracto acetónico mostró actividad contra S. aureus. Se logró aislar y caracterizar una cumarina y una hidroxiantraquinona del extracto crudo de R. birkelandi como metabolitos presentes en la fracción responsable de la actividad biológica presentada. La purificación y el aislamiento fueron llevados a cabo con técnicas cromatográficas y de extracción en fase sólida. La información estructural fue obtenida por análisis espectroscópicos: Ultravioleta (UV-Visible), Infrarrojo con Transformada de Fourier (FT-IR), Cromatografía Líquida acoplada a Espectrometría de Masas (LC/MS/MS), Cromatografía de Gases acoplada a Masas (GC-MS), Resonancia Magnética Nuclear de Protón (1H-NMR) y Resonancia Magnética de Carbono 13 (13C-NMR). Se recomiendan estudios futuros para la caracterización y la cuantificación de los principios activos de este extracto y una posible elucidación de sus mecanismos de acción.
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Krawczyk-Walach, Marta, Karolina Gzyra-Jagieła, Anna Milczarek e Jagoda Jóźwik-Pruska. "Characterization of Potential Pollutants from Poly(lactic acid) after the Degradation Process in Soil under Simulated Environmental Conditions". AppliedChem 1, n. 2 (10 dicembre 2021): 156–72. http://dx.doi.org/10.3390/appliedchem1020012.
Abstract (sommario):
In recent years, the amount of produced petrochemical plastic waste has been growing at an alarming rate. According to the Plastics Europe Market Research Group (PEMRG)/Conversio Market & Strategy GmbH, in 2018 the global production of plastics amounts to 359 million tons, and in Europe—61.8 million tons. More than 80% of all marine litter is plastic, which accumulates in the environment due to its durability. Due to the growing problem, biodegradable polymer products are introduced to the market. Therefore, it is necessary to conduct research on degradation products in order to estimate the risk arising from their presence in the environment. This paper discusses research on compounds that may potentially remain in the soil after the degradation of the double green PLA polymer. The aim of the research was to prove whether products made of PLA, e.g., packaging, films and other waste can release substances harmful to the environment. Therefore, soil was selected as a medium to characterize the substances potentially released from the polymer under conditions simulating the degradation process in the environment. The soil was always used from the same producer. Before the polymer biodegradation process, it was additionally checked for pH, C and N content, number of microorganisms, etc. PLA degradation in soil was carried out in a laboratory accredited by the Polish Accreditation Center (PCA). During the research, soil samples at various stages of the degradation process under laboratory conditions were subjected to both extraction in an aqueous environment and organic solvent extraction The studies used the gas chromatography coupled with mass spectrometry (GC/MS), as well as pyrolysis gas chromatography (Py-GC/MS). In addition, the study used the gel permeation chromatography (GPC/SEC) allowing to determine the distribution of molar masses, average molar masses and polydispersity, and the infrared spectroscopy (FTIR).
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Mogot, Rivaldo Lee, Dewa Anom e Jenny Kumajas. "Destilasi Kering Sampah Plastik Low Density Polyethylene (LDPE)". Fullerene Journal of Chemistry 5, n. 1 (27 aprile 2020): 5. http://dx.doi.org/10.37033/fjc.v5i1.131.
Abstract (sommario):
Indonesia is the second largest contributor of plastic waste in the world. Lack of public knowledge about the negative effects of plastic waste and the management of plastic waste that has not been good causes a buildup of plastic waste. This study aims to convert LDPE plastic waste into a liquid similar to petroleum, separate and analyze the chemical components present in the liquid produced by the distillation of dry plastic waste. Plastic waste is dry distilled at temperatures up to 300 oC, without solvents involved. Liquid distilled from a distillation of dry distillation (Fractionation) to separate the chemical components. To find out what chemical components are present, the resulting liquid from multilevel distillation (Fractionation) was analyzed by means of Infrared Spectroscopy (IR) and Gas Chromatography-Mass Spectrometry (GC-MS). The results of IR analysis on the LDPE plastic waste fractionation distillation fluid showed the presence of Aromatic, Alkane and Alkene functional groups. The results of GC-MS analysis on the LDPE plastic waste fractionation distillation fluid for each fraction showed that in general it is a group of hydrocarbon compounds with different molecular masses.
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Shynkarenko, Dmytro, Inna Konopatska, Roman Tsynda, Kostyantyn Коrol e Oleh Posilsksyi. "EXPERT RESEARCH OF SUBSTANCES OF GROUP OF DERIVATIVES OF PHENYLETHYLAMINE (ON EXAMPLE OF MESCALINE AND 2С-В)". Criminalistics and Forensics, n. 67 (2022): 379–95. http://dx.doi.org/10.33994/kndise.2022.67.39.
Abstract (sommario):
General physical and chemical descriptions of phenylethylamine presented grosses-formulas, the molecular masses and indexes of chromatography maintenance of derivatives of phenylethylamine, register in the article, mescaline, and 2С-В behave to that. During expert research of substances of a group of derivatives of phenylethylamine, the task of quality authentication of research objects that have an alike molecular structure stands before experts. The analytical approach intended for authentication of the investigated substances envisages the use of a few unconnected inter se methods: methods of providing of high level of selectivity, middle and subzero level of selectivity. The brought analytical charts over, that give a scientifically reasonable result, when after every method positive result that confirms each other are arrived at. The aim of the research of this work is an analysis and approbation of existent methodologies of authentication of substances that have an alike molecular structure, and their quantitative research. The process of quality authentication of mescaline and 2С-В, or other derivatives of phenylethylamine, includes for itself extraction and preparation of the test. During realization of screening of the investigated psychotropic substances (mescaline, 2С-В) used: method of quality analytical reactions, method of TLC, method of ultraviolet spectroscopy, method of infra-red spectroscopy, method of gas mass-spectrometry. Quantitative determination of mescaline and 2С-В was conducted by the method of gas mass-spectrometry. At the research of substances of a group of derivatives to the phenylethylamine expert, it follows to follow the presence of corresponding literary sources and the presence of corresponding analytical equipment (GC, GC/MS, LC/MS, and others like that). In accordance with it, it’s needed to use those or other methodologies of research of substances. The indicated methodologies are subject to obligatory verification before application in a laboratory. Key words: phenylethylamine, mescaline, 2C-B, chromatography, spectrophotometry, chromato-mass spectroscopy.
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Nelson, Michael A., John M. Ondov, Michael C. VanDerveer e Bruce A. Buchholz. "Contemporary Fraction of bis(2–ethylhexyl) Phthalate in Stilton Cheese by Accelerator Mass Spectrometry". Radiocarbon 55, n. 2 (2013): 686–97. http://dx.doi.org/10.1017/s0033822200057842.
Abstract (sommario):
Measurements of the radiocarbon abundance in 5 samples of bis(2–ethylhexyl) phthalate (DEHP) isolated from Stilton cheese were made by accelerator mass spectrometry (AMS) to determine the fraction of carbon originating from contemporary biogenic sources. DEHP is classified as a “priority hazardous substance” by the European Union, a probable human carcinogen by the United States Environmental Protection Agency, and is suspected to be a human endocrine disrupter. Measurement of its 14C abundance in a specific food indicates whether its presence is due to contamination from industrially synthesized DEHP or a naturally inherent component. A method was developed to determine the contemporary carbon fraction of DEHP in a fatty food matrix at concentrations of 0.14 mg/kg. Five 90–μg quantities of DEHP were extracted from 12 kg of Stilton cheese and isolated by silica gel, size exclusion, and high-performance liquid chromatography (HPLC). Masses of samples were determined by gas chromatography mass spectrometry (GC-MS) analyses prior to combustion and manometry afterwards. The purity of DEHP carbon mass in each isolate was determined by multivariate deconvolution of GCMS fragmentation spectra obtained from measurements of standards and isolates, and ranged from 88.0 ± 1.8% to 92.3 ± 1.1% (n = 5, 1σ). Concurrently processed isolation method blanks contained from 0.15 ± 0.04 to 1.52 ± 0.06 μg (n = 3, 1σ) DEHP per sample and significant quantities of pre- and post-chromatographic extraneous carbon contamination. The mean 14C-corrected contemporary carbon fraction of DEHP in the isolates was 0.235 ± 0.073 (1σ; and ± 0.091 at the 95% confidence level), revealing that the majority of DEHP in Stilton cheese results from anthropogenic sources, but with a significant naturally occurring component.
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Börner, Steffen, Hildburg Fry, Gabor Balizs e Reinhard Kroker. "Confirmation of Chloramphenicol Residues in Egg by Gas Chromatography/High-Resolution Mass Spectrometry and Comparison of Quantitation with Gas Chromatography–Electron Capture Detection". Journal of AOAC INTERNATIONAL 78, n. 5 (1 settembre 1995): 1153–60. http://dx.doi.org/10.1093/jaoac/78.5.1153.
Abstract (sommario):
Abstract Determination of chloramphenicol (CAP) residues in egg by gas chromatography/high-resolution mass spectrometry (GC/HRMS) with negative chemical ionization and gas chromatography with electron capture detection (GC–ECD) is described. A cleanup based on acetonitrile extraction followed by solid-phase extraction with silica gel and gel filtration columns was developed for extraction of CAP residues from whole egg. For quantitation, the internal standards used were the meta isomer of CAP (m-CAP) for GC–ECD and both m-CAP and deuterium-labeled CAP (D5-CAP) for GC/HRMS. For GC/HRMS, evaluation was performed by selecting characteristic ions at m/z 466 for CAP and m-CAP and at m/z 471 for D5-CAP. Both methods were validated with egg samples fortified at 0.4–2.0 μg/kg and lyophilized egg samples from animals treated at the 1 μg/kg concentration level. The coefficient of variation was below 10%. Limits of detection and quantitation of both methods were about 0.3 and 0.5 ng/kg, respectively. For confirmation of CAP residues, the relative ion abundance (m/z 466 and 468) was calculated. Further confidence was obtained by comparison of accurate monoisotopic masses from a spectrum library.
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Monga, Gaganpreet Kaur, Anima Ghosal e Dil Ramanathan. "To Develop the Method for UHPLC-HRMS to Determine the Antibacterial Potential of a Central American Medicinal Plant". Separations 6, n. 3 (29 luglio 2019): 37. http://dx.doi.org/10.3390/separations6030037.
Abstract (sommario):
The development of antibiotic resistance by microbials has long been acknowledged. The major challenge worldwide is to develop novel, natural, and potent antibiotics against the multidrug resistant bacteria. In this study, our aim was to develop the method for a highly sensitive instrument, ultra-high performance liquid chromatograph-high resolution mass spectrometer (UHPLC-HRMS), to evaluate the antibacterial property of a natural product. Aechmea magdalenae (Andre) Andre ex Baker, a plant belonging to the family Bromeliaceae, a native of Central America was used in this study. Based on the available literature, it was hypothesized that Aechmea magdalenae has antibacterial activity. In addition, the profiling done on A. magdalenae using gas chromatography-mass spectrometry (GC-MS) also revealed the presence of medicinally important chemical compounds, such as acetic acid. Minimum inhibitory concentration (MIC) of dried Aechmea plant extract was determined for the first time using 96-well plate assay, followed by determination of antibacterial potential using LC-MS. The reason being that other dried methanolic plant extracts, such as Vismia macrophylla, lined up for antibacterial testing have dark extracts, for which determining the antibacterial potential and reading the results with the naked eye would be challenging. To overcome the situation of dark plant extracts, a generalized novel LC-MS method was developed that was used for the plant A. magdalenae, and would be used further for other plants. A blue indicator called resazurin was added to the wells; resazurin, upon incubation with the living cells, got reduced to resorufin (which was pink), while it remained blue with bacterial growth inhibition. The mass difference created due to reduction of resazurin to resorufin was detected by using LTQ Orbitrap Discovery in positive ion mode to determine the antibacterial activity of the plant extract. The sample preparation for LC-MS assay included centrifugation of the samples taken from 96-well plate, followed by filtration of the supernatant, before exposing them to C-18 column. The results obtained from full scan LC-MS spectrum consistently demonstrated the presence of resorufin from wells with bacterial growth, and resazurin from wells with inhibition through peaks of relevant masses.
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Colville, Louise, Tim R. Marks, Hugh W. Pritchard, Ceci C. Custódio e Nelson B. Machado-Neto. "Development of a reliable GC-MS method for fatty acid profiling using direct transesterification of minimal quantities of microscopic orchid seeds". Seed Science Research 26, n. 1 (22 dicembre 2015): 84–91. http://dx.doi.org/10.1017/s0960258515000367.
Abstract (sommario):
AbstractOrchid seeds are among the smallest seeds in nature and they are naturally rich in fatty acids. However, the fatty acid composition of orchid seeds has not been investigated because the sample masses utilized for widely used methods for fatty acid profiling would generally require prohibitively large numbers (i.e. 10,000s) of seeds. The present work aimed to develop a method for fatty acid analysis using gas chromatography–mass spectrometry on small quantities (mg) of seeds. The method was developed using the seeds of two species, Dactylorhiza fuchsii, a temperate terrestrial, and Grammatophyllum speciosum, a tropical epiphyte. A range of sample masses was tested to determine the minimum mass required to achieve reliable fatty acid composition data. A direct transesterification method was used, which did not require extraction of fatty acids from seeds prior to analysis, and the effects of seed processing (crushed versus intact seeds) and incubation time in toluene on fatty acid yield were tested. Stable fatty acid profiles were obtained using as little as 10 mg of seeds. Neither crushing the seeds nor extending the toluene incubation step had much effect on the fatty acid yield. The simple direct transesterification method presented will enable the fatty acid composition of orchid seeds, and possibly other small seeds, to be determined reliably for studies into seed development, storage and germination.
30
Sieg, K., E. Starokozhev, E. Fries, S. Sala e W. Püttmann. "n-Aldehydes (C<sub>6</sub>–C<sub>10</sub>) in snow samples collected at the high alpine research station Jungfraujoch during CLACE 5". Atmospheric Chemistry and Physics Discussions 9, n. 2 (26 marzo 2009): 8071–99. http://dx.doi.org/10.5194/acpd-9-8071-2009.
Abstract (sommario):
Abstract. Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch, Switzerland, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 in February and March 2006. Sampling was carried out on the Sphinx platform. Headspace-solid-phase-dynamic extraction (HS-SPDE) combined with gas chromatography/mass spectrometry (GC/MS) was used to quantify C6–C10 n-aldehydes in the snow samples. The most abundant n-aldehyde was n-hexanal (median concentration 1.324 μg L−1) followed by n-nonanal, n-decanal, n-octanal and n-heptanal (median concentrations 1.239, 0.863, 0.460, and 0.304 μg L−1, respectively). A wide range of concentrations was found among individual snow samples, even for samples taken at the same time. Higher median concentrations of all n-aldehydes were observed when air masses reached Jungfraujoch from the north-northwest in comparison to air masses arriving from the southeast-southwest. Results suggest that the n-aldehydes detected most likely are of direct and indirect biogenic origin, and that they entered the snow through the particle phase.
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MAULANA, YUSUF EKA, TRISNA YULIANA e AINI ASPIATI ROHMAH. "Identifikasi Senyawa BTEX pada Asap Kendaraan Bermotor Roda Dua". Jurnal Reka Lingkungan 9, n. 2 (24 giugno 2020): 71–83. http://dx.doi.org/10.26760/rekalingkungan.v9i2.71-83.
Abstract (sommario):
AbstrakPenggunaan kendaraan bermotor roda dua di Indonesia semakin berkembang pesat. Semakin tinggi tingkat penggunaan transportasi yang beroperasi disuatu daerah, maka akan semakin tinggi pula potensi pencemaran udara di daerah tersebut. Jika pembakaran pada kendaraan bermotor tidak sempurna maka dapat dihasilkan senyawa yang berbahaya yaitu benzene (C6H6), toluene (C7H8), ethylbenzene (C8H9), dan xylene (C8H10) atau biasa disingkat BTEX. Tujuan penelitian ini adalah untuk mengidentifikasi senyawa BTEX dan senyawa hidrokarbon lainnya dalam asap kendaraan bermotor dengan menggunakan kromatografi gas-spektrometer massa (GC-MS). Hasil identifikasi menunjukkan adanya hubungan yangsangat kuat antara standard dengan hasil pengukuran yaitu dengan R2 di atas 0,99. Identifikasi menunjukkan senyawa BTEX yang terbentuk adalah Benzene, Toluene, Etil Benzene, Xylene.Kata kunci: kendaraan bermotor, hidro karbon, BTEX, GC-MS.AbstractThe use of two wheels motorized vehicles or motorcycles in Indonesia is growing rapidly. It has been known that the greater the number of two wheels motorized vehicles the higher the potential for air pollution. If the combustion occur incomplete, hazardous compounds can be generated, namely benzene (C6H6), toluene (C7H8), ethylbenzene (C8H9), and xylene (C8H10) or commonly abbreviated BTEX. The purpose of this study was to identify BTEX compounds and other hydrocarbon compounds in motor vehicle fumes using gas chromatography-mass spectrometers. The identification results indicate a very strong relationship between the standard and the measurement results, with R2 above 0.99. Identification shows that BTEX compounds formed are Benzene, Toluene, Ethyl Benzene, Xylene. Keywords: motorcycles, hidro karbon, BTEX, GC-MS.
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Asra, Ridho, R. Rusdi, Putut Arifin e N. Nessa. "ANALISIS SENYAWA BERBAHAYA PARFUM ISI ULANG YANG DIJUAL DI KOTA PADANG MENGGUNAKAN METODE KROMATROGRAFI GAS-SPEKTROMETRI MASSA". Jurnal Riset Kimia 10, n. 1 (30 marzo 2019): 20. http://dx.doi.org/10.25077/jrk.v12i2.324.
Abstract (sommario):
Perfume is widely used by most of people in this world. The increasing demand of perfume has caused many producers cheating by adding dangerous compounds and also unregistered by the National Agency of Drug and Food Control Indonesia. The aim of this study is to analyze the dangerous compounds in unregistered perfumes sold in Pasar Raya Padang City by using gas chromatography-mass spectrometry (GC-MS) method. In this Study, samples (A, B, C, D and E) were collected and the value of specific weight and refractive index of the samples were analyzed. The results showed that five samples contained relatively similar chemical compounds. Twelve compounds were detected and seven of them were harmful to health in refill perfumes which were dipropylene glycol, linalool, lily aldehyde, benzenepentanol, dimethylbenzyl carbinyl acetate, dihydro methyl jasmonate, alpha hexyl cinnamic aldehyde, based on Material Safety Data Sheet (MSDS). Regular monitoring of chemicals used in the manufacture of perfumes which may cause health risks to users should be controlled by National Agency of Drug and Food Control Indonesia.
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Rheamyta Carissa Siregar e Mahmiah. "Blue Energy dari Mikroalga Chlorella sp. sebagai Bahan Baku Biodiesel". Jurnal Riset Kelautan Tropis (Journal Of Tropical Marine Research) (J-Tropimar) 5, n. 2 (1 novembre 2023): 79–85. http://dx.doi.org/10.30649/jrkt.v5i2.73.
Abstract (sommario):
Biodiesel merupakan bioenergi bersih terbarukan karena dapat dihasilkan dari minyak nabati. Salah satu upaya dalam meningkatkan kemandirian energi di bidang kelautan (blue energy) adalah dengan menyiapkan bahan bakar alternatif potensial yang berasal dari mikroalga. Mikroalga mempunyai keunggulan dibandingkan jenis tumbuhan lain, karena pertumbuhan mikroalga sangat produktif serta laju pertumbuhannya sangat cepat dan tidak membutuhkan lahan yang subur, sehingga tidak bersaing dengan tanaman pangan. Beberapa mikroalga memiliki kandungan minyak hingga sebesar 80% dari massa tubuhnya. Bertujuan untuk memberikan informasi tentang perbedaan metode ekstraksi dan identifikasi kandungan minyak dengan mikroalga jenis Chlorella sp. yang dapat menjadikan bahan baku biodiesel. Metode penelitihan ini menggunakan analisis FTIR (Fourier Transform Infrared) dan GC-MS (Gas Chromatography-Mass Spectrometry). Hasil penelitian menunjukkan metode ekstraksi soxhlet dapat memisahkan biodiesel serta identifikasi bahan baku biodiesel diperoleh presentase minyak mikroalga dan kandungan senyawa. Senyawa yang paling dominan yaitu senyawa Asam Linoleat, senyawa Asam Palmitat, yang di dominasi oleh senyawa Asam Stearat.
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Bekka-Hadji, Fahima, Isabelle Bombarda, Ferhat Djoudi, Sofiane Bakour e Abdelaziz Touati. "Chemical Composition and Synergistic Potential of Mentha pulegium L. and Artemisia herba alba Asso. Essential Oils and Antibiotic against Multi-Drug Resistant Bacteria". Molecules 27, n. 3 (7 febbraio 2022): 1095. http://dx.doi.org/10.3390/molecules27031095.
Abstract (sommario):
The essential oils were obtained by hydrodistillation from aerial parts of Mentha pulegium L. (M. pulegium L.) and Artemisia herba alba (A. herba alba) Asso. and analyzed by gas chromatography–flame ionization detector chromatograpy (GC–FID) and gaz chromatography–mass spectrometry (GC–MS). The antibacterial activities of the oils were determined by the disk diffusion method and a microdilution broth assay against six bacteria stains. The combinations of these essential oils with antibiotics were evaluated against two multi-drug-resistant bacteria strains: imipenem-resistant Acinetobacter baumannii (IRAB S3310) and methicillin-resistant Staphylococcus aureus (MRSA S19). The chemical analysis of M. pulegium essential oil revealed the presence of pulegone (74.8%) and neoisomenthol (10.0%). A. herba alba essential oil was characterized by camphor (32.0%), α-thujone (13.7%), 1,8-cineole (9.8%), β-thujone (5.0%), bornéol (3.8%), camphene (3.6%), and p-cymene (2.1%). All strains tested except Pseudomonas aeruginosa were susceptible to these oils. The combinations of essential oils with antibiotics exerted synergism, antagonism, or indifferent effects. The best effect was observed with A. herba alba essential oil in association with cefoxitin (CX) against MRSA S19. However, for IRAB S3310, the strongest synergistic effect was observed with M. pulegium in association with amikacin (AK). This study demonstrated that M. pulegium and A. herba alba essential oils have antibacterial activities which could be potentiated by antibiotics especially in the case of IRAB S3310.
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Coggon, Matthew M., Chelsea E. Stockwell, Megan S. Claflin, Eva Y. Pfannerstill, Lu Xu, Jessica B. Gilman, Julia Marcantonio et al. "Identifying and correcting interferences to PTR-ToF-MS measurements of isoprene and other urban volatile organic compounds". Atmospheric Measurement Techniques 17, n. 2 (31 gennaio 2024): 801–25. http://dx.doi.org/10.5194/amt-17-801-2024.
Abstract (sommario):
Abstract. Proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) is a technique commonly used to measure ambient volatile organic compounds (VOCs) in urban, rural, and remote environments. PTR-ToF-MS is known to produce artifacts from ion fragmentation, which complicates the interpretation and quantification of key atmospheric VOCs. This study evaluates the extent to which fragmentation and other ionization processes impact urban measurements of the PTR-ToF-MS ions typically assigned to isoprene (m/z 69, C5H8H+), acetaldehyde (m/z 45, CH3CHO+), and benzene (m/z 79, C6H6H+). Interferences from fragmentation are identified using gas chromatography (GC) pre-separation, and the impact of these interferences is quantified using ground-based and airborne measurements in a number of US cities, including Las Vegas, Los Angeles, New York City, and Detroit. In urban regions with low biogenic isoprene emissions (e.g., Las Vegas), fragmentation from higher-carbon aldehydes and cycloalkanes emitted from anthropogenic sources may contribute to m/z 69 by as much as 50 % during the day, while the majority of the signal at m/z 69 is attributed to fragmentation during the night. Interferences are a higher fraction of m/z 69 during airborne studies, which likely results from differences in the reactivity between isoprene and the interfering species along with the subsequent changes to the VOC mixture at higher altitudes. For other PTR masses, including m/z 45 and m/z 79, interferences are observed due to fragmentation and O2+ ionization of VOCs typically used in solvents, which are becoming a more important source of anthropogenic VOCs in urban areas. We present methods to correct these interferences, which provide better agreement with GC measurements of isomer-specific molecules. These observations show the utility of deploying GC pre-separation for the interpretation PTR-ToF-MS spectra.
36
Sipahelut, Sophia G. "Perbandingan Komponen Aktif Minyak Atsiri dari Daging Buah Pala Kering Cabinet Dryer Melalui Metode Distilasi Air dan Air-Uap". AGRITEKNO, Jurnal Teknologi Pertanian 8, n. 1 (6 settembre 2019): 8–13. http://dx.doi.org/10.30598/jagritekno.2019.8.1.8.
Abstract (sommario):
The demand for essential oils has increased recently due to the growing of parfume, cosmetic, pharacentical, food and beverage, natural flavourings, medicines, aroma therapy, as well as non-food industries. Nutmeg fruit flesh is one of the potential sources of essential oils which can be obtained by both water distilation and water-steam distillation. Gas Chromatography-Mass Spectometry (GC-MS) is a dynamic analytical method to separate and to detect volatile compounds in a mixture. This study was aimed to compare active components of essential oils from cabinet dryer-dried nutmeg fruit flesh by water distillation and water-steam distillation. Results showed that 28 compounds were detected in essential oils of nutmeg flesh by water distillation, while 31 were identified in oil by water-steam distillation. Compounds identified with higher intensity in oil by water distillation were α-pinene (15.8%), β-pinene (12.0%), limonene (7.5%), δ-terpinene (8.7%), terpinene-4 -ol (14.4%), α-terpineol (4.9%), and myristicin (15.6%). The similar compounds were also detected in oil by water-steam distillation but in different quantities such as 13,3%, 8,8%, 7,2%, 8,7%, 15,6%, 7,7%, 13,5%, respectively.
Keywords: distillation method, essential oil component, GC-MS, nutmeg fruit flesh
ABSTRAK
Perkembangan industri parfum, kosmetik, farmasi, makanan dan minuman, penyedap alami, obat-obatan, aroma terapi, maupun industri bukan makanan semakin tahun semakin meningkat yang berakibat meningkatnya kebutuhan minyak atsiri. Daging buah pala menjadi salah satu potensi sumber minyak atsiri yang dapat diperoleh melalui metode distilasi (distilasi air dan distilasi air-uap). Kromatografi Gas Spectrometer Massa (GC-MS) merupakan metode yang dinamis untuk pemisahan dan deteksi senyawa-senyawa yang mudah menguap dalam suatu campuran. Tujuan penelitian ini adalah membandingkan komponen senyawa aktif minyak atsiri dari daging buah pala kering cabinet dryer yang diperoleh dari distilasi air dan distilasi air-uap menggunakan GC-MS. Hasil analisis GC-MS minyak atsiri daging buah pala yang diperoleh melalui distilasi air terdapat 28 senyawa, sedangkan dengan distilasi air-uap diperoleh 31 senyawa. Intensitas tertinggi pada metode distilasi air teridentifikasi sebagai senyawa α-pinene (15,8%), β-pinene (12,0%), limonene (7,5%), δ-terpinene (8,7%), Terpinene-4-ol (14,4%), α-terpineol (4,9%), dan myristicin (15,6%), sedangkan intensitas tertinggi pada metode distilasi air-uap teridentifikasi sebagai senyawa α-pinene (13,3%), β-pinene (8,8%), Limonene (7,2%), δ-terpinene (8,7%), terpinene-4-ol (15,6%), α-terpineol (7,7%), dan myristicin (13,5%).
Kata kunci: daging buah pala, GC-MS, komponen minyak atsiri, metode distilasi
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Петрова (Petrova), Наталья (Natal'ya) Валериевна (Valerievna), Катерина (Katerina) Владимировна (Vladimirovna) Сазанова (Sazanova), Нина (Nina) Анатольевна (Аnatol'evna) Медведева (Medvedeva) e Алексей (Аleksej) Леонидович (Leonidovich) Шаварда (Shavarda). "METABOLOMIC PROFILE AT THE DIFFERENT STAGES OF PRUNELLA VULGARIS (LAMIACEAE) ONTOGENESIS AT GROWING IN THE CLIMATE CHAMBER". chemistry of plant raw material, n. 3 (4 aprile 2018): 139–48. http://dx.doi.org/10.14258/jcprm.2018033798.
Abstract (sommario):
By gaz chromatography-mass spectrometry (GC-MS) technique based metabolite profiling of the methanol extract derived from leaves of Prunella vulgaris L. (Lamiaceae) was carried out. P. vulgaris was grown in climatic chamber. For every metabolomics profile, we estimated 102 target substances, and 41 of them were identified. Metabolite spectrum on vegetation stage is different than other stage by absent of groups: amino acids, terpenes and lipids. Comparison of the results of statistical analysis based on the data array, including all detected metabolites (metabolite profiling) show, that metabolomes of blossom and fructification stage of plants match often and only a small number of metabolites P. vulgaris at the this stage make it specific. It was studied the spatial heterogeneity in the structure of the metabolic network. The results of it are showed that metabolomes variety of the leaves from one plants much more than local variety in the range of parts of one leaf. Spatial distributions of metabolites of heterogeneity in a leaf have been illustrated on the example of threonic acid.
38
Shawn, Samuel T., Sean W. Harshman, Christina N. Davidson, Jae Hwan Lee, Anne E. Jung, Ariel Parker, M. Aaron Hawkins, Blake W. Stamps, Rhonda L. Pitsch e Jennifer A. Martin. "Sterilization and reuse of masks for a standardized exhaled breath collection device by autoclaving". Journal of Breath Research 17, n. 3 (30 giugno 2023): 036006. http://dx.doi.org/10.1088/1752-7163/ace127.
Abstract (sommario):
Abstract Exhaled breath research has been hindered by a lack of standardization in collection and analysis methodologies. Recently, the Respiration Collector for In Vitro Analysis (ReCIVA) sampling device has illustrated the potential to provide a consistent and convenient method for exhaled breath collection onto adsorbent media. However, the significant costs, compared to exhaled breath bags, associated with the standardized collector is believed to be the reason for limited widespread use by researchers in the exhaled breath field. For example, in addition to the sampling hardware, a single-use disposable silicon mask affixed with a filter is required for each exhaled breath collection. To reduce the financial burden, streamline device upkeep, reduce waste material, and ease the logistical burden associated with the single use masks, it is hypothesized that the consumable masks and filters could be sterilized by autoclaving for reuse. The masks were contaminated, autoclaved, and then tested for any surviving pathogens with spore strip standards and by measuring the optical density of cultures. The compound background collected when using the ReCIVA with new masks was compared to that collected with repeatedly autoclaved masks via thermal desorption gas chromatography mass spectrometry (TD-GC-MS). The capacity to block particulate matter of new filters was tested against that of autoclaved filters by introducing an aerosol and comparing pre-filter and post-filter particle counts. Finally, breath samplings were conducted with new masks and autoclaved masks to test for changes in measurements by TD-GC-MS of exogenous and endogenous compounds. The data illustrate the autoclave cycle sterilizes masks spiked with saliva to background levels (p = 0.2527). The results indicate that background levels of siloxane compounds are increased as masks are repetitively autoclaved. The data show that mask filters have significant breakthrough of 1 μm particles after five repetitive autoclaving cycles compared to new filters (p = 0.0219). Finally, exhaled breath results utilizing a peppermint ingestion protocol indicate two compounds associated with peppermint, menthone and 1-Methyl-4-(1-methylethyl)-cyclohexanol, and an endogenous exhaled breath compound, isoprene, show no significant difference if sampled with a new mask or a mask autoclaved five times (p > 0.1063). Collectively, the data indicate that ReCIVA masks and filters can be sterilized via autoclave and reused. The results suggest ReCIVA mask and filter reuse should be limited to three times to limit potentially problematic background contaminants and filter dysfunction.
39
Grant, Gary G., Jian Guo, Linda MacDonald e Melanie D. Coppens. "Oviposition response of spruce budworm (Lepidoptera: Tortricidae) to host terpenes and green-leaf volatiles". Canadian Entomologist 139, n. 4 (agosto 2007): 564–75. http://dx.doi.org/10.4039/n06-079.
Abstract (sommario):
AbstractA dual-choice behavioral bioassay and gas chromatography – electroantennogram detection (GC–EAD) were used to determine the effect of host terpenes and nonhost green-leaf volatiles (GLVs) on the oviposition preference of the spruce budworm, Choristoneura fumiferana (Clemens). Some emphasis was placed on assessing the ability of females to distinguish between enantiomers of chiral monoterpenes because (+)-α-pinene but not (–)-α-pinene or (±)-α-pinene had been shown previously to promote oviposition. Headspace volatiles from white spruce, Picea glauca (Moench) Voss (Pinaceae), and balsam fir, Abies balsamea (L.) Mill. (Pinaceae), were sampled using solid-phase microextraction and identified by gas chromatography – mass spectrometry with the aid of a chiral column. Females deposited significantly more egg masses on filter paper substrate treated with host monoterpenes than on controls. Contrary to expectation, substrates treated with several GLVs were also preferred over the controls. None of the GLVs or terpenes was deterrent. Females showed no significant ability in either the behavioral or the GC–EAD bioassays to distinguish between enantiomers of selected chiral monoterpenes, including α-pinene, in contrast to earlier findings. We conclude that host terpenes serve as general rather than host-specific oviposition stimuli for spruce budworm.
40
Habti, Fatima, Soumia Belouafa, Ahmed Bennamara, Mustapha Tarhy, Noureddine Fatini, Abdelmjid Bahloul e Abdelmjid Abourriche. "DEVELOPPEMENT AND VALIDATION OF A QUECHERS EXTRACTION BASED GAZ CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY ``GC-MS/MS`` METHOD FOR THE DETERMINATION OF 7 POLYCHLORINATED BIPHENYLS RESIDUES IN BIVALVES "OYTERS"." International Journal of Advanced Research 5, n. 7 (31 luglio 2017): 1160–70. http://dx.doi.org/10.21474/ijar01/4824.
41
Qin, Ning, Xiang-Zhen Kong, Ying Zhu, Wei He, Qi-Shuang He, Bin Yang, Hui-Ling Ou-Yang, Wen-Xiu Liu, Qing-Mei Wang e Fu-Liu Xu. "Distributions, Sources, and Backward Trajectories of Atmospheric Polycyclic Aromatic Hydrocarbons at Lake Small Baiyangdian, Northern China". Scientific World Journal 2012 (2012): 1–13. http://dx.doi.org/10.1100/2012/416321.
Abstract (sommario):
Air samples were collected seasonally at Lake Small Baiyangdian, a shallow lake in northern China, between October 2007 and September 2008. Gas phase, particulate phase and dust fall concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured using a gas chromatograph-mass spectrometer (GC-MS). The distribution and partitioning of atmospheric PAHs were studied, and the major sources were identified; the backward trajectories of air masses starting from the center of Lake Small Baiyangdian were calculated for the entire year. The following results were obtained: (1) The total concentration of 16 priority controlled PAHs (PAH16) in the gas phase was417.2±299.8 ng·m−3, in the particulate phase was150.9±99.2 ng·m−3, and in dust fall was6930.2±3206.5 ng·g−1. (2) Vehicle emission, coal combustion, and biomass combustion were the major sources in the Small Baiyangdian atmosphere and accounted for 28.9%, 45.1% and 26.0% of the total PAHs, respectively. (3) Winter was dominated by relatively greater PAHs polluted northwesterly air mass pathways. Summer showed a dominant relatively clean southern pathway, whereas the trajectories in autumn and spring might be associated with high pollution from Shanxi or Henan province.
42
Oteef, Mohammed D. Y., Khadejah D. Otaif e Abubakr M. Idris. "Personal Protective Equipment as a Potential Source of Phthalate Exposure during the COVID-19 Pandemic". Applied Sciences 13, n. 16 (9 agosto 2023): 9076. http://dx.doi.org/10.3390/app13169076.
Abstract (sommario):
Personal protective equipment (PPE)—especially face masks, face shields, and gloves—was used to minimize the spread of COVID-19. PPE is primarily made of plastic materials with various plastic additives, such as phthalate plasticizers. Phthalates are linked with various adverse health effects. Therefore, this study investigated the amounts of six commonly used phthalates (DBP, BBP, DEHP, DnOP, DINP, and DIDP) in different types of PPE samples collected during the pandemic. Gas chromatography–mass spectrometry (GC–MS) was used to detect six selected phthalates and other organic chemicals in PPE samples. The quality of data was ensured using certified reference materials, internal standards, procedural blanks, and replicate analyses. The total phthalate content found in face shields and face masks was in the range of 0.29 µg/g to 942.60 µg/g, with DBP, DEHP, and DINP detected most frequently. A health risk assessment concluded that the determined levels were not expected to pose adverse health effects on the wearer. However, the findings of this study suggest that chronic daily intakes of phthalates from two vinyl glove samples with phthalate content exceeding 11% and 14% (w/w) of the glove’s weight may potentially increase the risk of cancer in humans. In addition to the target phthalates, flame retardants and other plasticizers (e.g., organophosphates and dioctyl isophthalate) were tentatively identified in various PPE samples.
43
Leibrock, E., L. G. Huey, P. D. Goldan, W. C. Kuster, E. Williams e F. C. Fehsenfeld. "Ground-based intercomparison of two isoprene measurement techniques". Atmospheric Chemistry and Physics 3, n. 1 (3 febbraio 2003): 67–72. http://dx.doi.org/10.5194/acp-3-67-2003.
Abstract (sommario):
Abstract. An informal intercomparison of two isoprene (C5H8) measurement techniques was carried out during Fall of 1998 at a field site located approximately 3 km west of Boulder, Colorado, USA. A new chemical ionization mass spectrometric technique (CIMS) was compared to a well-established gas chromatographic technique (GC). The CIMS technique utilized benzene cation chemistry to ionize isoprene. The isoprene levels measured by the CIMS were often larger than those obtained with the GC. The results indicate that the CIMS technique suffered from an anthropogenic interference associated with air masses from the Denver, CO metropolitan area as well as an additional interference occurring in clean conditions. However, the CIMS technique is also demonstrated to be sensitive and fast. Especially after introduction of a tandem mass spectrometric technique, it is therefore a candidate for isoprene measurements in remote environments near isoprene sources.
44
Costa Lourenço, Yanka Beatriz, Alexandre Santos Pimenta, Leoclécio Luís de Paiva, Francisco Marlon Carneiro Feij´o, Maíra Fasciotti, Renato Vinicius Oliveira Castro e Elias Costa de Souza. "Eucalyptus Wood Vinegar: Chemical Profiling, Evaluation of Acute Toxicity to Artemia salina and Effect on the Hatching of Betta splendens Eggs". Ensaios e Ciência C Biológicas Agrárias e da Saúde 25, n. 5-esp (14 marzo 2022): 776–82. http://dx.doi.org/10.17921/1415-6938.2021v25n5-espp776-782.
Abstract (sommario):
In Brazil nowadays, eucalyptus wood vinegar (WV) is an important input in food industry and for agriculture and veterinary uses. The main objectives of the present research work were to characterize the phenolic fraction in the industrial WV by gas chromatography and mass spectrometry, evaluate the acute toxicity of industrial WV to the brine shrimp Artemia salina, and assess the effect of the product on the hatching of Betta splendens eggs. Two types of WV were employed in the experiments, raw and bi-distilled WV. Both were profiled by gas chromatography and mass spectrometry (GC/MS). Bioassays with Artemia salina nauplii were performed to determine the acute toxicity of WV. To assess the effect of WV on the hatching of B. splendens eggs, five concentrations of bi-distilled WV were employed encompassing one control and four experimental treatments, 0% (T0), 0.025% (T1), 0.050% (T2), 0.075% (T3) and 0.100% (T4) with ten replicates per treatment. Probit and regression analysis were applied to the experimental data of the brine shrimp bioassay and the experiment with the bettas, respectively. Phenols reported in the literature as having biological activity were identified in the WV by GC/MS. Median lethal doses (LD50) equal to 272 and 298 mg mL‑1 were determined for the raw and bi-distilled WV, respectively. Regarding the experiment with B. splendens eggs, a concentration of 0.05% was found ideal to reach maximum of hatching and minimize the fungal infection in the fingerlings. The bi-distilled WV has potential to be applied in the commercial production of this fish species, with significant decrease in mortality rates. Keywords: Eucalyptus Wood Vinegar. Eucalyptus Pyroligneous Extract. Phenolic Compounds. Acute Toxicity. Artemia salina. Antifungal Activity. Betta splendens Resumo Atualmente no Brasil, o extrato pirolenhoso de eucalipto (EP) é um importante insumo na indústria de alimentos e também para uso na agricultura e veterinária. Os principais objetivos do presente trabalho de pesquisa foram avaliar a toxicidade aguda do EP industrial para em Artemia salina e o efeito do produto na eclosão de ovos de Betta splendens. Dois tipos de EP foram empregados nos experimentos, EP bruto e bidestilado. Ambos foram analisados por cromatografia gasosa e espectrometria de massa (GC/MS). Bioensaios com náuplios de A. salina foram realizados para determinar a toxicidade aguda do EP. Para avaliar o efeito do EP na eclosão de ovos de B. splendens, cinco concentrações de EP bidestilado foram empregadas perfazendo 5 tratamentos, 0% (T0), 0,025% (T1), 0,050% (T2), 0,075% (T3) e 0,100% (T4) com dez repetições por tratamento. Os dados experimentais do bioensaio com A. salina e do experimento com B. splendens foram submetidos à análise Probit e de regressão, respectivamente. Todos os fenóis relatados na literatura como tendo atividade biológica foram identificados no EP por GC/MS. Doses letais medianas (DL50) iguais a 272 e 298 mg mL-1 foram determinadas para o EP bruto e bidestilado, respectivamente. Em relação ao experimento B. splendens, a concentração de 0,05% foi considerada ideal para atingir o máximo de eclosão e minimizar a infecção fúngica nos alevinos. O EP bidestilado tem potencial para ser aplicado na produção comercial dessa espécie de peixe, com queda significativa nas taxas de mortalidade. Palavras-chave: Extrato Pirolenhoso de Eucalipto. Compostos Fenólicos. Toxicidade Aguda. Artemia salina. Atividade Antifúngica. Betta splendens
45
Costa Lourenço, Yanka Beatriz, Alexandre Santos Pimenta, Leoclécio Luís de Paiva, Francisco Marlon Carneiro Feij´o, Maíra Fasciotti, Renato Vinicius Oliveira Castro e Elias Costa de Souza. "Eucalyptus Wood Vinegar: Chemical Profiling, Evaluation of Acute Toxicity to Artemia salina and Effect on the Hatching of Betta splendens Eggs". Ensaios e Ciência C Biológicas Agrárias e da Saúde 25, n. 5-esp. (14 marzo 2022): 776–82. http://dx.doi.org/10.17921/1415-6938.2021v25n5-esp.p776-782.
Abstract (sommario):
In Brazil nowadays, eucalyptus wood vinegar (WV) is an important input in food industry and for agriculture and veterinary uses. The main objectives of the present research work were to characterize the phenolic fraction in the industrial WV by gas chromatography and mass spectrometry, evaluate the acute toxicity of industrial WV to the brine shrimp Artemia salina, and assess the effect of the product on the hatching of Betta splendens eggs. Two types of WV were employed in the experiments, raw and bi-distilled WV. Both were profiled by gas chromatography and mass spectrometry (GC/MS). Bioassays with Artemia salina nauplii were performed to determine the acute toxicity of WV. To assess the effect of WV on the hatching of B. splendens eggs, five concentrations of bi-distilled WV were employed encompassing one control and four experimental treatments, 0% (T0), 0.025% (T1), 0.050% (T2), 0.075% (T3) and 0.100% (T4) with ten replicates per treatment. Probit and regression analysis were applied to the experimental data of the brine shrimp bioassay and the experiment with the bettas, respectively. Phenols reported in the literature as having biological activity were identified in the WV by GC/MS. Median lethal doses (LD50) equal to 272 and 298 mg mL‑1 were determined for the raw and bi-distilled WV, respectively. Regarding the experiment with B. splendens eggs, a concentration of 0.05% was found ideal to reach maximum of hatching and minimize the fungal infection in the fingerlings. The bi-distilled WV has potential to be applied in the commercial production of this fish species, with significant decrease in mortality rates. Keywords: Eucalyptus Wood Vinegar. Eucalyptus Pyroligneous Extract. Phenolic Compounds. Acute Toxicity. Artemia salina. Antifungal Activity. Betta splendens Resumo Atualmente no Brasil, o extrato pirolenhoso de eucalipto (EP) é um importante insumo na indústria de alimentos e também para uso na agricultura e veterinária. Os principais objetivos do presente trabalho de pesquisa foram avaliar a toxicidade aguda do EP industrial para em Artemia salina e o efeito do produto na eclosão de ovos de Betta splendens. Dois tipos de EP foram empregados nos experimentos, EP bruto e bidestilado. Ambos foram analisados por cromatografia gasosa e espectrometria de massa (GC/MS). Bioensaios com náuplios de A. salina foram realizados para determinar a toxicidade aguda do EP. Para avaliar o efeito do EP na eclosão de ovos de B. splendens, cinco concentrações de EP bidestilado foram empregadas perfazendo 5 tratamentos, 0% (T0), 0,025% (T1), 0,050% (T2), 0,075% (T3) e 0,100% (T4) com dez repetições por tratamento. Os dados experimentais do bioensaio com A. salina e do experimento com B. splendens foram submetidos à análise Probit e de regressão, respectivamente. Todos os fenóis relatados na literatura como tendo atividade biológica foram identificados no EP por GC/MS. Doses letais medianas (DL50) iguais a 272 e 298 mg mL-1 foram determinadas para o EP bruto e bidestilado, respectivamente. Em relação ao experimento B. splendens, a concentração de 0,05% foi considerada ideal para atingir o máximo de eclosão e minimizar a infecção fúngica nos alevinos. O EP bidestilado tem potencial para ser aplicado na produção comercial dessa espécie de peixe, com queda significativa nas taxas de mortalidade. Palavras-chave: Extrato Pirolenhoso de Eucalipto. Compostos Fenólicos. Toxicidade Aguda. Artemia salina. Atividade Antifúngica. Betta splendens
46
Ali, Akhtar, Yasmeen M. Bashmil, Jeremy J. Cottrell, Hafiz A. R. Suleria e Frank R. Dunshea. "LC-MS/MS-QTOF Screening and Identification of Phenolic Compounds from Australian Grown Herbs and Their Antioxidant Potential". Antioxidants 10, n. 11 (5 novembre 2021): 1770. http://dx.doi.org/10.3390/antiox10111770.
Abstract (sommario):
Culinary spices and herbs have been used to impart a characteristic flavour and aroma in food due to their appealing fragrance. Recently, bioactive compounds from herbs, especially phenolics, have gained much attention due to their potential health outcomes. The aim of this study was to characterize and quantify the phenolic compounds from 10 widely used Australian-grown herbs (oregano, rosemary, bay, basil, sage, fenugreek, dill, parsley, mint and thyme). For this purpose, liquid chromatography mass spectrometry (LC-MS) was used for the complete profiling of polyphenolic compounds and quantification of abundant phenolic compounds was completed with high-performance liquid chromatography—photodiode array detection (HPLC-PDA). Polyphenols from Australian-grown herbs were estimated through total phenolic content (TP), total flavonoids (TF) and total tannins (TT) along with their in-vitro antioxidant activities. Oregano and mint were estimated with the highest value of TP (140.59 ± 9.52 and 103.28 ± 8.08 mg GAE/g, milligram gallic acid equivalent/gram) while rosemary and mint had the highest TF (8.19 ± 0.74 and 7.05 ± 0.43 mg QE (quercetin equivalent)/g). In this study, eighty-four (84) phenolic compounds were screened and confirmed through LC-MS/MS by comparing their masses and fragmentation pattern with published libraries. The results of this study validate the use of these herbs as bioactives and their positive impact on human health.
47
Koss, Abigail R., Kanako Sekimoto, Jessica B. Gilman, Vanessa Selimovic, Matthew M. Coggon, Kyle J. Zarzana, Bin Yuan et al. "Non-methane organic gas emissions from biomass burning: identification, quantification, and emission factors from PTR-ToF during the FIREX 2016 laboratory experiment". Atmospheric Chemistry and Physics 18, n. 5 (7 marzo 2018): 3299–319. http://dx.doi.org/10.5194/acp-18-3299-2018.
Abstract (sommario):
Abstract. Volatile and intermediate-volatility non-methane organic gases (NMOGs) released from biomass burning were measured during laboratory-simulated wildfires by proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF). We identified NMOG contributors to more than 150 PTR ion masses using gas chromatography (GC) pre-separation with electron ionization, H3O+ chemical ionization, and NO+ chemical ionization, an extensive literature review, and time series correlation, providing higher certainty for ion identifications than has been previously available. Our interpretation of the PTR-ToF mass spectrum accounts for nearly 90 % of NMOG mass detected by PTR-ToF across all fuel types. The relative contributions of different NMOGs to individual exact ion masses are mostly similar across many fires and fuel types. The PTR-ToF measurements are compared to corresponding measurements from open-path Fourier transform infrared spectroscopy (OP-FTIR), broadband cavity-enhanced spectroscopy (ACES), and iodide ion chemical ionization mass spectrometry (I− CIMS) where possible. The majority of comparisons have slopes near 1 and values of the linear correlation coefficient, R2, of > 0.8, including compounds that are not frequently reported by PTR-MS such as ammonia, hydrogen cyanide (HCN), nitrous acid (HONO), and propene. The exceptions include methylglyoxal and compounds that are known to be difficult to measure with one or more of the deployed instruments. The fire-integrated emission ratios to CO and emission factors of NMOGs from 18 fuel types are provided. Finally, we provide an overview of the chemical characteristics of detected species. Non-aromatic oxygenated compounds are the most abundant. Furans and aromatics, while less abundant, comprise a large portion of the OH reactivity. The OH reactivity, its major contributors, and the volatility distribution of emissions can change considerably over the course of a fire.
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Leibrock, E., L. G. Huey, P. D. Goldan, W. C. Kuster, E. Williams e F. C. Fehsenfeld. "Ground-based intercomparison of two isoprene measurement techniques". Atmospheric Chemistry and Physics Discussions 2, n. 3 (24 giugno 2002): 905–20. http://dx.doi.org/10.5194/acpd-2-905-2002.
Abstract (sommario):
Abstract. An informal intercomparison of two isoprene (C5H8) measurement techniques was carried out during Fall of 1998 at a field site located approximately 3 km west of Boulder, Colorado, USA. A new chemical ionization mass spectrometric technique (CIMS) was compared to a well-established gas chromatographic technique (GC). The CIMS technique utilized benzene cation chemistry to ionize isoprene. The isoprene levels measured by the CIMS were often larger than those obtained with the GC. The results indicate that the CIMS technique suffered from an interference associated with air masses from the Denver, CO metropolitan area. However, the CIMS technique is also demonstrated to be sensitive and fast and is a candidate for isoprene measurements in remote environments near isoprene sources.
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Bezuglaya, Elena, Igor Zinchenko, Nikolay Lyapunov, Hanna Vlasenko e Vladimir Musatov. "Substantiation of an approach to determination of ketoprofen macrogol 400 esters". ScienceRise: Pharmaceutical Science, n. 3(31) (30 giugno 2021): 51–63. http://dx.doi.org/10.15587/2519-4852.2021.235980.
Abstract (sommario):
The aim. The work is concerned with the substantiation of the approach to the identification and quantitative determination of ketoprofen macrogol 400 esters. Materials and methods. Ketoprofen, macrogol 400, ketoprofen macrogol 400 ester (KM400E), as well as model cream-gels were studied by the following methods: absorption spectrophotometry ultraviolet (UV) and visible, high-performance liquid chromatography (HPLC), gas chromatography (GC), GC / mass spectrometry, nuclear magnetic resonance (NMR) spectrometry and thermogravimetry. Results. It was found by GC and GC / mass spectrometry that the average molecular mass (Mr) of the test macrogol 400 is 383.50 and it contains oligomers with molecular masses from 150.17 to 546.65. KM400E, which is a mixture of esters of ketoprofen with macrogol oligomers, was synthesized. The formed esters were characterized by 1H NMR spectra. It was shown that the ratio of the average molecular mass of KM400E, calculated for monoesters, and the molecular mass of ketoprofen corresponds to the ratio of specific absorbances of solutions of ketoprofen and solutions of KM400E, this fact indicated the formation of monoesters. Taking into account the risk of variability of the fractional composition of macrogol 400 in different batches, it is advisable to quantify KM400E using ketoprofen reference standard (RS) and not KM400E RS. Using HPLC with diode array detection the peak of KM400E should be identified by the UV absorption spectrum with λmax≈255 nm, which is characteristic for ketoprofen, and the relative retention time (RRt) of the peak; KM400E should be quantified by the content of ketoprofen in this impurity. During storage of model cream-gels the content of KM400E impurity is significantly lower than the content of ketoprofen propylene glycol ester (mixture of isomers). Conclusions. The approach to the identification and quantitative determination of KM400E is substantiated. The analytical procedure for determination of KM400E impurity by HPLC with a diode array detection using ketoprofen RS was developed. Correctness of the procedure was proved by the results of the validation studies.
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Laube, J. C., e A. Engel. "First atmospheric observations of three chlorofluorocarbons". Atmospheric Chemistry and Physics Discussions 8, n. 2 (7 aprile 2008): 6683–95. http://dx.doi.org/10.5194/acpd-8-6683-2008.
Abstract (sommario):
Abstract. We report the first atmospheric observations of the Chlorofluorocarbons (CFCs) trifluorochloroethene, 3-chloropentafluoropropene and 4,4-dichlorohexafluoro-1-butene by means of Gas Chromatography with Electron Capture and Mass Spectrometric detection (GC-ECD-MS) in air samples taken at the Taunus Observatory operated by the University of Frankfurt (Main) and the Jungfraujoch High Altitude Research Station in Switzerland. These substances belong to a class of CFCs containing a double bond and are suspected to originate from the production and thermal degradation of widely used fluoropolymers like polychlorotrifluoroethene (PCTFE). Their atmospheric lifetimes are expected to be rather short. As a quantitative calibration is not available for these species by now we use a relative sensitivity method to estimate the observed atmospheric abundances. Identification was possible because of an air plume containing high concentrations of these substances. We suggest that the abundances found on this occasion originated from a local source. However, we have also observed the novel CFCs in air masses representative of background conditions, though with much lower concentrations. These species and some of their degradation products are toxic and could also be relevant for stratospheric and tropospheric ozone depletion.