Artículos de revistas: "Liquid chromatography research"

1

Yatsenko, Larisa Anatolyevna, Maria Yurevna Printseva, Ilya Danilovich Cheshko y Artur Alexandrovich Tumanovsky. "Detection of residues and determination of the composition of combustible components in case of explosions of vapor-gas-air mixtures". Technology of technosphere safety 97 (2022): 51–60. http://dx.doi.org/10.25257/tts.2022.3.97.51-60.

Texto completo

Resumen

Introduction. Liquefied hydrocarbon gases (LHG) are widely used in various fields. The main components of LHG are: propane, isobutane and n-butane, which are not only combustible, but also explosive gases capable of detonation combustion. The detection of LHG in the air is a very urgent task in expert studies. To determine the component composition of various flammable liquids, for the purpose of their identification, chromatographs equipped with a capillary quartz column with a phase that allows detecting saturated hydrocarbons of the homologous series from pentane to pentatetracontane inclusive are used in the Forensic Expertise Institutions of Federal Fire Service of EMERCOM of Russia. However, it is not possible to analyze the component composition of lighter hydrocarbons according to the previously proposed and used in expert practice method for detecting and studying flammable liquids/high liquids under these conditions. To solve the problem of unification of the use of the instrumental base for the detection of residues of flammable liquids, liquid liquids and light hydrocarbons, new chromatography conditions were selected using the existing equipment set. Goals and objectives. The aim of the study is to select the analysis conditions for detecting the remains of liquefied hydrocarbon gases after explosions of steam-air mixtures on the basis of the instrumental gas chromatographic complex in service with the Forensic Expertise Institutions of Federal Fire Service of EMERCOM of Russia. Research methods. To detect and determine the composition of residues of combustible components during explosions of vapor-gas-air mixtures, a hardware-software instrumental complex based on a gas-liquid chromatograph equipped with a flame ionization detector, a ZB-50 capillary column, and an attachment from a two-stage thermal desorber was used. Results and its discussion. In the course of the study, the optimal conditions for conducting gas chromatographic analysis were defined and selected in order to detect liquefied hydrocarbon gases. Recommended pressures are given for various carrier gases. It is shown that, by varying the pressure and inlet temperature, light hydrocarbons propane, butane, isobutane is fairly well separated on a gas-liquid chromatograph with a flame ionization detector and on a ZB-50 capillary column 30 meters long. Conclusion. The research shows that the problem of combining a hardware-software instrumental complex based on a gas chromatograph with an attachment from a two-stage thermal desorber used for the analysis of two groups of substances (liquefied hydrocarbons and flammable liquids, gas liquids) is solved by varying the pressure and temperature of the input. Keywords: gas-liquid chromatography, thermal desorption, liquefied petroleum gases, light hydrocarbons, air-fuel mixtures, vapor-gas-air mixtures, explosion, fire examination.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Lange, Mike, Zhixu Ni, Angela Criscuolo y Maria Fedorova. "Liquid Chromatography Techniques in Lipidomics Research". Chromatographia 82, n.º 1 (16 de noviembre de 2018): 77–100. http://dx.doi.org/10.1007/s10337-018-3656-4.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Wang, Peng, Jun Cai, Dong Hao Li y Xiang Fan Piao. "Research on Multidimensional Liquid Chromatography Sample Pretreatment System". Applied Mechanics and Materials 701-702 (diciembre de 2014): 832–35. http://dx.doi.org/10.4028/www.scientific.net/amm.701-702.832.

Texto completo

Resumen

Using multidimensional liquid chromatography technology, a liquid chromatography sample pretreatment system which was controlled by a microcontroller was designed. Real sample pretreatment experiments have been done. The experimental results showed that the complex samples can be separated effectively with this system according to 3 polarities. The operation of this system is simple, fast and high automatic, which meet the requirements of pretreatment of liquid chromatography complex samples.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

YANG, Sandong, Naijie LI, Zhou MA, Tao TANG y Tong LI. "Research advances in nano liquid chromatography instrumentation". Chinese Journal of Chromatography 39, n.º 10 (1 de octubre de 2021): 1065–76. http://dx.doi.org/10.3724/sp.j.1123.2021.06017.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

van de Meent, Michiel H. M. y Gerhardus J. de Jong. "Novel liquid-chromatography columns for proteomics research". TrAC Trends in Analytical Chemistry 30, n.º 11 (diciembre de 2011): 1809–18. http://dx.doi.org/10.1016/j.trac.2011.06.012.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Arnold, P. J., R. Guserle, V. Luckow, R. Hemmer y H. Grote. "Liquid chromatography-mass spectrometry in metabolic research". Journal of Chromatography A 554, n.º 1-2 (agosto de 1991): 267–80. http://dx.doi.org/10.1016/s0021-9673(01)88455-7.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Dembek, Mikołaj y Szymon Bocian. "Stationary Phases for Green Liquid Chromatography". Materials 15, n.º 2 (6 de enero de 2022): 419. http://dx.doi.org/10.3390/ma15020419.

Texto completo

Resumen

Industrial research, including pharmaceutical research, is increasingly using liquid chromatography techniques. This involves the production of large quantities of hazardous and toxic organic waste. Therefore, it is essential at this point to focus interest on solutions proposed by so-called “green chemistry”. One such solution is the search for new methods or the use of new materials that will reduce waste. One of the most promising ideas is to perform chromatographic separation using pure water, without organic solvents, as a mobile phase. Such an approach requires novel stationary phases or specific chromatographic conditions, such as an elevated separation temperature. The following review paper aims to gather information on stationary phases used for separation under purely aqueous conditions at various temperatures.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Schmidt, Axel, Fabian Mestmäcker, Lisa Brückner, Tobias Elwert y Jochen Strube. "Liquid-Liquid Extraction and Chromatography Process Routes for the Purification of Lithium". Materials Science Forum 959 (junio de 2019): 79–99. http://dx.doi.org/10.4028/www.scientific.net/msf.959.79.

Texto completo

Resumen

Since several years, the lithium market is characterized by high growth rates especially due to the increasing demand for lithium-ion batteries. Therefore, the primary production is currently expanded and there is a growing interest in recycling. However, because of the chemical properties of lithium, many production processes lack efficient processes for the separation, concentration and purification of lithium. This article reviews the current use of liquid-liquid extraction (LLE) and chromatography in lithium production as well as research. Currently, the industrial application of LLE and chromatography in lithium purification is limited to the extraction of impurities and co-products. Extraction of lithium is only used as concentration step in few processes before lithium precipitation. In research and development, a wide variety of extractants and resins is investigated. In LLE, chelating extractants like crown ethers and calixarene and synergistic systems show the greatest potential. In the chromatographic separation the main focus of research lies upon cation exchange media, especially media with sulfonated ligands. However, most research is still in early development. Therefore, extensive research is needed to enable the industrial use of optimized LLE and chromatography processes in lithium production. Content TOC \o "1-3" \h \z \u HYPERLINK \l "_Toc515547308" Abstract PAGEREF _Toc515547308 \h 2 HYPERLINK \l "_Toc515547309" Content PAGEREF _Toc515547309 \h 3

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Kataev, S. S., O. N. Dvorskaya, M. A. Gofenberg, A. V. Labutin y A. B. Melentyev. "ANALYTICAL FEATURES OF SYNTHETIC MDMB(N)-073F CANNABIMIMETICS AND ITS MARKERS IN BIOLOGICAL MATERIAL". Pharmacy & Pharmacology 7, n.º 4 (10 de septiembre de 2019): 184–97. http://dx.doi.org/10.19163/2307-9266-2019-7-4-184-197.

Texto completo

Resumen

The aim of the research is to study both analytical features of synthetic MDMB(N)-073F cannabimimetics of indazole carboxamides group by gas chromatography methods combined with tandem mass spectrometry (GC-MS) and high performance liquid chromatography with high-resolution mass spectrometry (HPLC-HRMS) as well as characteristics of the major MDMB(N)-073F metabolite, its glucuronide and derivatives, using gas chromatography with mass-spectrometric (GC-MS) detection and high-performance liquid chromatography (HPLC) with MS/MS mass spectrometry (HPLC-MS/MS) in urine samples to be applied in expert practice, chemical-toxicological and forensic and chemical analyses.Materials and methods. To carry out the study, the following materials were used: plant-based objects with narcotic drugs withdrawn from illegal trafficking and applied to them;. urine samples to be studied under chemical-toxicological and forensic and chemical analyses. For solid-phase epitaxy, SampliQ EVIDEX TFE cartridges – 200 mg – 3 ml (Agilent, USA) were used for sample preparation; β-glucuronidase, Type HP-2, From Helix Pomatia, 100000 UA/ml (Sigma-ALDRICH CHEMI, Germany) was used for enzymatic hydrolysis. GC-MS/MS analysis was made using Agilent 7890 gas chromatograph with a tandem quadrupolar mass-spectrometer Agilent 7000 (Agilent, США); GC-MS analysis was carrid out using gas chromatograph Agilent 7820 with mass-selective detector Agilent 5975 (Agilent, USA); HPLC-HRMS research was made on liquid chromatograph Agilent 1260 with tandem hybrid high-resolution quadrupole-time-of-flight detector Agilent 6540 (Agilent, США); liquid chromatograph Agilent 1260 with Agilent 6460 (Agilent, USA) with tandem mass-spectrometer were used for making HPLC-MS/MS research.Results. The structure of MDMB(N)-073F compound has been confirmed and an exact mass of the protonated molecule corresponding to the chemical formula C19H27FN3O3 fixed by GC-MS/MS and HPLC-HRMS methods. Spectral characteristics of MDMB(N)-073F have been given. One of the branches in MDMB(N)-073F biotransformation in the human body found out by GC-MS and HPLC-MS/MS methods, is the ester decomposition with further conjugation of the resulting acid. The product interacting with glucuronic acid, is found to be the conjugate of major MDMB(N)-073F metabolite of the Ist phase in biotransformation. Metabolites appearing due to the ester decomposition and its conjugate with glucuronic acid, are recommended to be used as markers for synthetic MDMB(N)-073F cannabimimetics in the analysis by chromatographic methods; they can be used for regular screening of biological samples.Conclusion. The research results presented here, are the following: the analytical features characteristic for synthetic MDMB(N)-073F cannabimimetics found out by gas chromatography methods combined with tandem mass spectrometry (GC-MS/ MS) and liquid chromatography of hybrid high-resolution quadrupole-time-of-flight mass spectrometry (HPLC-HRMS), as well as characteristics of major MDMB(N)-073F metabolite, its glucuronide and derivatives with the use of gas chromatography with mass-spectrometric detection (GC-MS) and liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS) in urine samples to be applied in expert practice, chemical-toxicological, forensic and chemical analyses.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Wang, Chao, Qiang Ma y Xing Wang. "Determination of Alkylphenol Ethoxylates in Textiles by Normal-Phase Liquid Chromatography and Reversed-Phase Liquid Chromatography/Electrospray Mass Spectrometry". Journal of AOAC INTERNATIONAL 90, n.º 5 (1 de septiembre de 2007): 1411–17. http://dx.doi.org/10.1093/jaoac/90.5.1411.

Texto completo

Resumen

Abstract Comprehensive analytical methods based on pressurized liquid extraction followed by normal-phase liquid chromatography (NPLC) with ultraviolet detection and reversed-phase liquid chromatography (RPLC)/electrospray mass spectrometry (MS) have been developed for determination of alkylphenol ethoxylates (APEOs) in textile samples. NPLC with an aminosilica column allowed for the chromatographic separation of APEOs according to the increasing number of ethylene units and revealed the exact distribution of individual oligomers. RPLC coupled with electrospray MS was highly sensitive and enabled the complete qualitative and quantitative determination of individual APEOs in textile samples. The 2 analytical methods based on different chromatographic separation mechanisms, i.e., NPLC and RPLC, may provide complementary information of APEOs in textile materials. The 2 detection methods were successfully applied to the investigation of various textile samples, and the data of our research suggested actual pollution in real textile products.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Gama, M. R., C. H. Collins y C. B. G. Bottoli. "Nano-Liquid Chromatography in Pharmaceutical and Biomedical Research". Journal of Chromatographic Science 51, n.º 7 (12 de abril de 2013): 694–703. http://dx.doi.org/10.1093/chromsci/bmt023.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Forcisi, Sara, Franco Moritz, Basem Kanawati, Dimitrios Tziotis, Rainer Lehmann y Philippe Schmitt-Kopplin. "Liquid chromatography–mass spectrometry in metabolomics research: Mass analyzers in ultra high pressure liquid chromatography coupling". Journal of Chromatography A 1292 (mayo de 2013): 51–65. http://dx.doi.org/10.1016/j.chroma.2013.04.017.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Wang, Jian Ming, Ai Hua Ao, Chang Sheng Qiao, Yu Zhong y Yuan Yuan Zhang. "The Research Progress of Melanin". Advanced Materials Research 204-210 (febrero de 2011): 2057–60. http://dx.doi.org/10.4028/www.scientific.net/amr.204-210.2057.

Texto completo

Resumen

The sources of melanin and the sorts of melanin are introduced. New techniques for extraction and analysis of natural melanin were introduced. New analytical techniques are high performance liquid chromatography, high-speed countercurrent chromatography, high performance capillary electrophoresis and chromatography-mass spectrometry. The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. The applications of melanin are introduced.

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Alves de Castro, Artur Eduardo, Roberto Da Silva Gusmão, Dirceu Aparecido Gonçalves de Souza, Honoria Paula Alves de Sa, Regina Mara Silva Pereira y Márcio Luiz Dos Santos. "Surgimento e Evolução do Cromatógrafo Líquido de Ultra Alta Eficiência (UPLC), sua Aplicabilidade, Vantagens e Desvantagens". UNICIÊNCIAS 25, n.º 2 (14 de diciembre de 2021): 86–92. http://dx.doi.org/10.17921/1415-5141.2021v25n2p86-92.

Texto completo

Resumen

A cromatografia líquida convencional é uma técnica analítica que consome uma grande quantidade de solventes orgânicos, comprometendo parte significativa dos gastos com laboratórios de controle de qualidade, desenvolvimento analítico e de estabilidade nas indústrias farmacêuticas, que levou os pesquisadores a buscarem meios e alternativas que pudessem mitigar este impacto econômico e ecológico. O Cromatógrafo Líquido de Ultra Alta Eficiência ou Ultra-High Performance Liquid Chromatography – UHPLC ou UPLC - foi uma alternativa desenvolvida com esses propósitos, alternativamente às análises cromatográficas convencionalmente executadas por aparelhos de Cromatografia Líquida de Alta Eficiência ou High Performance Liquid Chromatograph – HPLC. O objetivo do trabalho é traçar um histórico da evolução do UPLC, que possibilitou o melhoramento da técnica cromatográfica de alta eficiência, quanto ao tempo de análise e, consequentemente, redução do uso de solventes a partir dos princípios do HPLC, técnica atualmente utilizada com a maior quantidade de equipamentos instalados nos centros de pesquisa e universidades, além de laboratórios de rotina, de pesquisa e desenvolvimento das indústrias farmacêuticas em todo o mundo. Os resultados alcançados em relação à precisão analítica equivalente ou superior, redução do tempo de análise, redução do consumo de solventes orgânicos e, consequentemente, redução considerável do custo de análises quando comparados à Cromatografia Líquida de Alta Eficiência convencional, garantiram o sucesso da implantação desta técnica analítica, que vem ganhando espaço considerável nesses ambientes. Palavras-chave: UPLC. UHPLC. HPLC. Abstract Conventional liquid chromatography is an analytical technique that consumes a large quantity of organic solvents, compromising a significant part of the costs in quality control laboratories, analytical development and stability in pharmaceutical industries, which led researchers to search for ways and alternatives that could mitigate this economic and ecological impact. The Ultra-High Performance Liquid Chromatography - UHPLC - (or UPLC - Ultra Performance Liquid Chromatography) - was an alternative developed for these purposes to the chromatographic analyses conventionally performed by High Performance Liquid Chromatography - HPLC devices. The objective of this study is to trace a history of the UPLC evolution, which enabled the improvement of the high efficiency chromatographic technique, regarding the time of analysis and, consequently, reduction of the use of solvents from the HPLC principles, technique currently used with the largest amount of equipment installed in research centres and universities, besides routine laboratories, research and development of pharmaceutical industries around the world. The results achieved regarding the equivalent or superior analytical precision, reduction of analysis time, reduction of organic solvents consumption and consequently considerable reduction of theanalysis cost when compared to conventional High Performance Liquid Chromatography, guaranteed the success of the implementation of this analytical technique, which has been gaining considerable space in these environments. Keywords: UPLC. UHPLC. HPLC.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Wang, Ze, Qi Wang, Jinkui Zhang, Pengcheng Lin y Jun Dang. "An Integrated Chromatographic Strategy for the Large-Scale Extraction of Ergosterol from Tulasnellaceae sp." Separations 9, n.º 7 (17 de julio de 2022): 176. http://dx.doi.org/10.3390/separations9070176.

Texto completo

Resumen

A reliable chromatographic strategy is crucial for the extraction of target compounds from natural sources as it is related to the preparation efficiency, as well as the purity of the compounds. In this study, medium-pressure normal-phase liquid chromatography and high-pressure reverse-phase liquid chromatography were combined to prepare and purify ergosterol from Tulasnellaceae sp of Gymnadenia orchidis. First, Tulasnellaceae sp. was extracted three times (2.0 L and 2 h each time) with ethyl acetate, and the 6.0 L of extract solution was concentrated under reduced pressure to yield 2.2 g of crude sample. Then, the crude sample was pretreated utilizing silica gel medium-pressure liquid chromatography to enrich the target ingredient (586.0 mg). Finally, high-pressure reversed-phase liquid chromatography was used to purify the target compound, and the compound was characterized as ergosterol (purity > 95%) using spectral data. Overall, the simple and reproducible integrated chromatographic strategy developed in this study has the potential for the large-scale purification of steroids for laboratory and even industrial research. To the best of our knowledge, this is also the first report of ergosterol in Tulasnellaceae sp.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Karimkulov, Kurbonkul Mavlankulovich, Ikromjon Esanboyevich Uzoha, Madraim Khasanovich-Sarikulov y Azada Abdurakhmanova. "Classification and research of food gas liquid chromatography method". ACADEMICIA: An International Multidisciplinary Research Journal 10, n.º 11 (2020): 1008–19. http://dx.doi.org/10.5958/2249-7137.2020.01454.8.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Frank, C., V. Karl, A. Kaunzinger y K. Schumacher. "High performance liquid chromatography in food control and research". Journal of Chromatography A 653, n.º 2 (noviembre de 1993): 385–86. http://dx.doi.org/10.1016/0021-9673(93)83201-3.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Yang, Jun, Guowang Xu, Yufang Zheng, Hongwei Kong, Chang Wang, Xinjie Zhao y Tao Pang. "Strategy for metabonomics research based on high-performance liquid chromatography and liquid chromatography coupled with tandem mass spectrometry". Journal of Chromatography A 1084, n.º 1-2 (agosto de 2005): 214–21. http://dx.doi.org/10.1016/j.chroma.2004.10.100.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Scherbyna, O. "EXPERIMENTAL STUDIES ON THE DETECTION AND QUANTIFICATION OF VOLATILE FLAMMABLE AND TOXIC SUBSTANCES IN THE AIR AND BIOLOGICAL FLUIDS OF THE ORGANISM". Fire Safety, n.º 32 (14 de agosto de 2018): 74–79. http://dx.doi.org/10.32447/20786662.32.2018.11.

Texto completo

Resumen

The methods of isolation, purification and qualitative and quantitative determination of phenol in air and biological fluids of an organism are offered. Isolation was carried out by distillation with water vapor, purification by extraction with chloroform, and identification by qualitative reactions, by chromatography in a thin layer of sorbent and by liquid chromatography. The quantitative determination of phenol was carried out by liquid chromatography in a reverse phase (chromatograph "Tsvet-304" with an ultraviolet detector). Calculation of the quantitative content of phenol was carried out by the method of absolute calibration. As a result of the research, it was found that by using the molecular liquid chromatography method, it is possible to determine 17-20% of phenol isolated from urine and 21-24% isolated from the air. The retention time of phenol 1h.14s, the results of the analysis are well reproducible. The worked out techniques have high resolution, high sensitivity and speed of analysis.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Akhtayeva, M. B. y G. Ye Azimbayeva. "Research of amino acid content of Cichorium intybus L. and Urtica dioica L. by means of gas-liquid chromatography". Bulletin of the Karaganda University. "Chemistry" series 95, n.º 3 (30 de septiembre de 2019): 8–13. http://dx.doi.org/10.31489/2019ch3/8-13.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Domnina, Yu M., V. V. Suslov, S. A. Kedik, E. V. Vorfolomeeva y A. V. Meleshko. "Quantitative Determination of Naltrexone Hydrochloride in a Nasal Spray by High-performance Liquid Chromatography". Drug development & registration 9, n.º 2 (30 de mayo de 2020): 98–104. http://dx.doi.org/10.33380/2305-2066-2020-9-2-98-104.

Texto completo

Resumen

Introduction. Naltrexone, an antagonist of µ-opioid receptors, is promising for the treatment of various autoimmune and oncological diseases when used in doses of 1.5–5 mg/day. To date, there are no medications that provide such dosages of naltrexone.Aim. Development and validation of a method for the quantitative determination of naltrexone hydrochloride in a nasal spray by high performance liquid chromatography (HPLC).Materials and methods. As an object of research, a naltrexone hydrochloride nasal spray was used. The quantitative determination of naltrexone in the test sample was developed using a Dionex UltiMate 3000 high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a diode-matrix detector.Results and discussion. The possibility of using isocratic and gradient chromatographic modes for the quantitative determination of naltrexone hydrochloride in the nasal spray was studied. Based on these results, a new method of determination using the gradient mode is proposed, which allows minimizing the influence of the polymer component in the test sample on the analysis results.Conclusion. A new technique of high-performance liquid chromatography (HPLC) is proposed that allows identification and quantification of naltrexone hydrochloride in a nasal spray containing a high concentration of water-soluble heat-sensitive poloxamer as a thickener. The developed method was validated according to the parameters: correctness, precision, specificity, linearity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Morley, Raena y Mirjana Minceva. "Liquid–Liquid Chromatography: Current Design Approaches and Future Pathways". Annual Review of Chemical and Biomolecular Engineering 12, n.º 1 (7 de junio de 2021): 495–518. http://dx.doi.org/10.1146/annurev-chembioeng-101420-033548.

Texto completo

Resumen

Since its first appearance in the 1960s, solid support–free liquid–liquid chromatography has played an ever-growing role in the field of natural products research. The use of the two phases of a liquid biphasic system, the mobile and stationary phases, renders the technique highly versatile and adaptable to a wide spectrum of target molecules, from hydrophobic to highly polar small molecules to proteins. Generally considered a niche technique used only for small-scale preparative separations, liquid–liquid chromatography currently lags far behind conventional liquid–solid chromatography and liquid–liquid extraction in process modeling and industrial acceptance. This review aims to expose a broader audience to this high-potential separation technique by presenting the wide variety of available operating modes and solvent systems as well as structured, model-based design approaches. Topics currently offering opportunities for further investigation are also addressed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Ashworth, Raymond B. "Liquid Chromatographic Assay of Tetracyclines in Tissues of Food-Producing Animals". Journal of AOAC INTERNATIONAL 68, n.º 5 (1 de septiembre de 1985): 1013–18. http://dx.doi.org/10.1093/jaoac/68.5.1013.

Texto completo

Resumen

Abstract A survey of the literature is presented on liquid chromatographic (LC) determination of tetracyclines in plasma, urine, and tissues of foodproducing animals. Food Safety and Inspection Service (FSIS) research on tetracyclines during 1973-1984 is discussed, including the thin layer chromatographic qualitative identification method for tissues. Research on development of LC column packings for trace level chromatography of tetracyclines and anhydrotetracyclines is also discussed. Data are shown for recovery, ruggedness testing, and analyst qualification studies on the tentative version of the LC method

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Zhang, Kai, Xianling Zheng, Hongfeng Zhang, Xueqiang Zhang, Yanmin Xu, Shiying Jin y Shuang Huo. "Research Progress on the Pharmacological Effects and Quality Analysis Methods of Bupleurum". Journal of Clinical and Nursing Research 6, n.º 3 (7 de abril de 2022): 7–13. http://dx.doi.org/10.26689/jcnr.v6i3.3836.

Texto completo

Resumen

Bupleurum has been used as traditional medicine in China, Japan, South Korea, and other Asian countries for more than 2,000 years. The crude extracts and pure compounds isolated from Bupleurum have a variety of biological activities, such as anti-inflammatory, anti-cancer, antipyretic, antibacterial, anti-viral, liver protection, neuroprotection, and immune regulation. The pharmacological effects of Bupleurum have been classified and summarized in this paper by consulting literatures at home and abroad. At the same time, the quality analysis methods of bupleurum, including high-performance liquid chromatography, thin layer chromatography, ultra-high-performance liquid chromatography mass spectrometry, UPLC-QTOF-MS, and so on, are discussed. This paper provides a reference for further research, development, and application of Bupleurum.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Bruns, Andreas. "Applications of preparative high-performance liquid chromatography in oleochemical research". Journal of Chromatography A 536 (enero de 1991): 75–84. http://dx.doi.org/10.1016/s0021-9673(01)89237-2.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Mellon, F. A., J. R. Chapman y J. A. E. Pratt. "Thermospray liquid chromatography—mass spectrometry in food and agricultural research". Journal of Chromatography A 394, n.º 1 (enero de 1987): 209–22. http://dx.doi.org/10.1016/s0021-9673(01)94173-1.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Varynskyi, B. "Historical essay of the development of chromatography at the Zaporizhzhia State Medical University." Zurnal Hromatograficnogo tovaristva 21, n.º 67 (14 de diciembre de 2022): 56–65. http://dx.doi.org/10.15407/zht2021.67.056.

Texto completo

Resumen

The purpose of this work is to analyze the chronology and state of development of chromatographic methods at the Zaporizhzhia State Medical University (ZSMU). A historical overview of the use of chromatographic methods at ZSMU is provided. First of all, emphasis is placed on the introduction of high-performance liquid chromatography and gas-liquid chromatography. The main scientific laboratories and groups that worked and are working at the Zaporizhzhia State Medical University in the field of instrumental chromatography are shown. There were groups at the Department of Biological Chemistry, the Department of Faculty Pediatrics, the Department of Physical and Colloidal Chemistry. Currently, the Department of Physical Colloid Chemistry is actively working on a new laboratory of liquid chromato-mass spectrometry of the Department of Experimental Pharmaceutical Research of the training medical-laboratory center. The laboratory performs research for many departments of ZSMU, including the Faculty of Pharmacy, the Faculty of Postgraduate Education, the Faculty of Medicine. The laboratory develops, validates and uses methods to establish the purity and confirm the molecular weight and structure of new biologically active substances synthesized to search for new drugs, research of impurities in drug substances, determination of biologically active substances in extracts of medicinal plant raw materials, determination of residual amounts drugs in poultry meat and eggs, and other livestock and poultry products, determination of concentrations of disease markers, determination of distribution, metabolism and excretion of drugs.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Yao, Shun, Yu Cao, Chun-mei Jia, Yan Wang y Hang Song. "Developments of instruments and methods related with high-speed countercurrent chromatography and their applications in research of natural medicines". Open Chemistry 10, n.º 3 (1 de junio de 2012): 417–32. http://dx.doi.org/10.2478/s11532-011-0141-4.

Texto completo

Resumen

AbstractHigh-speed countercurrent chromatography (HSCCC) is a liquid-liquid separation chromatographic technique which uses no solid supporting medium. During its rapid development in the last 30 years, great progress has been made in the instrumentation, the basic study and application of HSCCC. It has significant advantages over other instrumental separation techniques, in its high efficiency and continuous processing capability. In recent years, HSCCC has been widely used in research and development of natural medicines and functional foods, including preparative separation, fingerprint analysis and screening of bioactive constituents. A review of the technique is presented in this paper.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Shkurdoda, S., D. Shynkarenko, V. Pasichnyk, K. Korol y O. Posilskyi. "EXPERT STUDY OF ISONIAZIDE IN MEAT PRODUCTS". Criminalistics and Forensics, n.º 66 (2021): 785–99. http://dx.doi.org/10.33994/kndise.2020.66.57.

Texto completo

Resumen

The article deals with the recommendations for the detection of isoniazid in meat products, using the example of minced meat using physicochemical methods. This study does not lose its relevance over the years, due to the use of drugs for tuberculosis for poisoning homeless and domestic animals, in particular dogs, in different regions of Ukraine, the main active ingredient of which is isoniazid. The article describes a method for the extraction of isoniazid in food products of meat origin (minced meat, sausage), which presumably could or may be used to poison domestic animals, in particular dogs. Isoniazid was identified by the methods of qualitative color reactions, thin-layer chromatography, and gas chromatography with a mass-selective detector. The process of qualitative identification of isoniazid in foodstuffs that could or may be used to poison domestic animals, in particular dogs, includes: -the method of extraction and separation of interfering impurities, primarily fats, preliminary research by the method of qualitative analytical reactions; -studies by thin layer chromatography; -research by instrumental methods, in particular, gas chromatography with mass-selective detection. The method for extracting isoniazid from meat products described in the article is effective and allows you to get rid of interfering substances, especially fats. In addition, the method of gas chromatography with mass-selective detection has sufficient sensitivity and selectivity. It allows with a minimum number of interfering peaks of low intensity, determine the composition of isoniazid accurately. The specified list of instrumental base, methods and research techniques is not exhaustive. The examiner should be guided by the availability of relevant literature and the availability of appropriate analytical equipment (gas chromatograph, gas chromatograph with mass-selective detector, liquid chromatograph, liquid chromatograph with mass-selective detector, etc.). In accordance with this, it is necessary to use certain methods for studying substances. These methods are subject to mandatory verification before being used in the laboratory. The obtained research results allow us to recommend this technique for implementation in expert practice.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Kurbanoglu, Sevinc, Ozer Karsavurdan y Sibel A. Ozkan. "Recent Advances on Drug Analyses Using Ultra Performance Liquid Chromatographic Techniques and their Application to the Biological Samples". Current Analytical Chemistry 15, n.º 3 (7 de mayo de 2019): 277–93. http://dx.doi.org/10.2174/1573411014666180423152612.

Texto completo

Resumen

Introduction: Ultra-Performance Liquid Chromatographic (UPLC) method enables analyst to establish an analysis at higher pressure than High Performance Liquid Chromatographic (HPLC) method towards liquid chromatographic methods. UPLC method provides the opportunity to study a higher pressure compared to HPLC, and therefore smaller column in terms of particle size and internal diameter are generally used in drug analysis. The UPLC method has attracted gradually due to its advantages such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. In this review, the recent selected studies related to the UPLC method and its method validation are summarized. The drug analyses and the results of the studies which were investigated by UPLC method, with certain parameters from literature are presented. Background: Quantitative determination of drug active substances by High-Performance Liquid Chromatography (HPLC) from Liquid Chromatography (LC) methods has been carried out since the 1970's with the use of standard analytical LC methods. In today's conditions, rapid and very fast even ultra-fast, flow rates are achieved compared to conventional HPLC due to shortening analysis times, increasing method efficiency and resolution, reducing sample volume (and hence injection volume), reducing waste mobile phase. Using smaller particles, the speed and peak capacity are expanding to new limit and this technology is named as Ultra Performance Liquid Chromatography. In recent years, as a general trend in liquid chromatography, ultra-performance liquid chromatography has taken the place of HPLC methods. The time of analysis was for several minutes, now with a total analysis time of around 1-2 minutes. The benefits of transferring HPLC to UPLC are much better understood when considering the thousands of analyzes performed for each active substance, in order to reduce the cost of analytical laboratories where relevant analysis of drug active substances are performed without lowering the cost of research and development activities. Methods: The German Chemist Friedrich Ferdinand Runge, proposed the use of reactive impregnated filter paper for the identification of dyestuffs in 1855 and at that time the first chromatographic method in which a liquid mobile phase was used, was reviewed. Christian Friedrich Chönbein, who reported that the substances were dragged at different speeds in the filter paper due to capillary effect, was followed by the Russian botanist Mikhail S. Tswet, who planted studies on color pigment in 1906. Tswet observes the color separations of many plant pigments, such as chlorophyll and xanthophyll when he passes the plant pigment extract isolated from plant through the powder CaCO3 that he filled in the glass column. This method based on color separation gives the name of "chromatographie" chromatography by using the words "chroma" meaning "Latin" and "graphein" meaning writing. Results and Conclusion: Because the UPLC method can be run smoothly at higher pressures than the HPLC method, it offers the possibility of analyzing using much smaller column sizes and column diameters. Moreover, UPLC method has advantages, such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. The use of the UPLC method especially analyses in biological samples such as human plasma, brain sample, rat plasma, etc. increasingly time-consuming due to the fact that the analysis time is very short compared to the HPLC, because of the small amount of waste analytes and the considerable savings in their cost.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Кошеваров, N. Koshevarov, Абрамов, S. Abramov, Абрамова, E. Abramova, Мисюра et al. "Determination of fenbendazole and its metabolites in milk by the method of liquid chromatography coupled with tandem mass-spectrometry". Russian Journal of Parasitology 3, n.º 4 (25 de diciembre de 2016): 554–62. http://dx.doi.org/10.12737/23082.

Texto completo

Resumen

Objective of research: Development of methods for the determination of fenbendazole and its metabolites in milk by liquid chromatography coupled with tandem mass spectrometry. Materials and methods: Fenbendazole was administered orally to five cows. Samples of milk were taken on 1, 3, 5 and 10 days of drug application. The research method includes a description of reagents, plates and equipment; mass-spectrometric conditions for analysis of fenbendazole and its metabolites; preparation of the equipment to operation; preparation of eluent solution; preparation of the chromatograph to analysis; determination of chromatographic parameters of standard drug samples; preparation of milk samples to analysis; establishment of parameters of extracts’ chromatography; procedure of calibration of fenbendazole and its metabolites in eluent. Results and discussion: When studying the pharmacokinetics of fenbendazole and its metabolites (sulfone and sulfoxide) in milk, it was found that the maximal concentrations were determined 24 h after drug administration and were 22,6 ng/ml for fenbendazole sulfone, 34,0 ng/ml for fenbendazole sulfoxide and 19,7 ng/ml for fenbendazole. 10 days after treatment, the concentrations of fenbendazole and its metabolites in milk did not exceed permitted values.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Markova, E. B., A. S. Savchenko, A. G. Cherednichenko, Yu M. Averina y V. S. Boldyrev. "Research of the Processes of Chromatographic Analysis of Medicines on HKUST-1 Metal-Organic Framework Structures". Herald of the Bauman Moscow State Technical University. Series Natural Sciences, n.º 6 (93) (diciembre de 2020): 122–36. http://dx.doi.org/10.18698/1812-3368-2020-6-122-136.

Texto completo

Resumen

The paper studies the process of analysis of tetracycline and paracetamol with the use of the HKUST-1 organometallic framework sorbent by high performance liquid chromatography. To obtain experimental data using the previously described technique, a sample of the material under consideration was synthesized and its physicochemical properties were studied. It has been established that individual sorbent particles have an octahedral shape and have a porous structure capable of adsorbing chemical compounds of various nature. The specific surface of the sample was calculated using the BET method and was Ssp = 551.3 m2/g. The study notes that when water or aqueous-organic media are used as eluents for chromatographic analysis, sorbents based on HKUST-1 have low stability; their degradation is observed when passing eluent solutions in an amount equal to 300--500 volumes of the chromatographic column. When only organic solvents are used for chromatographic analysis of tetracycline and paracetamol in the temperature range of 25--45 °C, no decomposition of the HKUST-1 sorbent and no degradation of the analyzed drugs are observed. Findings of research show that the efficiency of the eluent increases in the tetrahydrofuran--methanol--acetonitrile series. For all organic solvents used, the retention times were determined, the degree of separation, HETP, and the speed of response were calculated at various temperatures. A complex of studies has proved the possibility of using the organometallic sorbent HKUST-1 for the effective separation of drug mixtures by high-performance liquid chromatography

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Павлюк, Б. В., Ю. Я. Мельник, Т. А. Грошовий, М. Б. Чубка y В. Й. Скорохода. "Research of water extraction from xenoderm as an active pharmaceutical ingredient in drugs". Farmatsevtychnyi zhurnal, n.º 5 (1 de octubre de 2020): 42–50. http://dx.doi.org/10.32352/0367-3057.5.20.05.

Texto completo

Resumen

Today, burns are one of the most common types of injuries in the home and at work around the world. Therefore, the issue of treatment of burns remains relevant today for medicine and pharmacy in particular. In Ukraine, the method of treatment of burns using xenodermoimplants from porcine skin is used, and therefore the crushed substrate of cryolyophilized porcine skin (xenoderm) is a promising active ingredient in the technology of various drug forms. The aim of the work was to study the structural and mechanical properties of water extract from the crushed substrate of the xenoderm and to determine its amino acid composition by using physicochemical analysis, namely using high performance liquid chromatography (HPLC). A glass pycnometer and a Heppler BH 2 MLW drop ball viscometer were used to determine the density and viscosity of the water extract from the xenoderm. The density and viscosity of the water extract were studied at different temperatures. The dependence of the density and viscosity of the water extract from the xenoderm on temperature was studied and it was found that with increasing temperature the dynamic viscosity decreases and the density changes slightly. A glass pycnometer and a viscometer with falling ball were used to determine the density and viscosity of the xenoderm water extract. Chromatographic separation of amino acids was performed on a liquid chromatograph Agilent 1200 with a fluorescent detector. Chromatographic determination of amino acids was performed on a liquid chromatograph Agilent 1200 (USA) with a fluorescent detector G1315A (USA) and an autosampler 1313A. Using the HPLC method, 16 amino acids were identified (essential – 6; conditionally – 2; nonessential – 8). Identified amino acids are almost in a bound state (1.5%), the largest amount is glutamic acid (0.23%), glycine (0.19%), aspartic acid (0.18%), proline (0.17%) and arginine (0.17%). In unbound form, the content of glutamic acid (0.09%) and glycine (0.06%) is the highest. Based on the results of research, you can choose quality indicators, to determine the appropriate criteria that can be proposed for the standardization of water extract from the crushed substrate of the xenoderm.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Kaleniecka, Aleksandra, Elżbieta Włodarczyk, Krzysztof Piaskowski, Lucyna Lewandowska y Paweł K. Zarzycki. "Unexpected Encapsulation of Selected Polycyclic Aromatic Hydrocarbons by β-Cyclodextrin Studied Using UV-Vis Spectrophotometry, Micro-Planar Chromatography and Temperature Dependent Inclusion Chromatography". Symmetry 12, n.º 12 (28 de noviembre de 2020): 1967. http://dx.doi.org/10.3390/sym12121967.

Texto completo

Resumen

This research communication significantly extends our previous studies focusing on the temperature effects related to the unexpected chromatographic behavior of 1-acenaphthenol in the presence of native β-cyclodextrin (β-CD) additive, working under thin-layer chromatographic (TLC) conditions. We have applied complementary and orthogonal techniques including (i) temperature-controlled ultraviolet-visible (UV-VIS) spectroscopy, (ii) thermostated microplanar high-performance chromatography (micro-HPTLC) and (iii) temperature-dependent inclusion chromatography based on high-performance liquid chromatography (HPLC) to investigate the retention behavior of related host molecules. Particularly, various symmetric and asymmetric molecules were tested, such as: naphthalene and its derivatives including acenaphthylene, acenaphthene and selected dimethynaphthalenes: 1,8-DMN, 1,5-DMN, 2,3-DMN and 2,6-DMN. Reported raw experimental data, particularly performed in liquid phase and detected by UV-Vis spectrophotometry, may suggest that solubility changes of the supramolecular complexes studied and differences in total analysis time between TLC and HPLC separation can trigger strong retention of target components in planar chromatographic systems. This was also supported by principal component analysis (PCA) of the multi-source data obtained. It is hoped that the reported analyses enable the adjustment of phenomenological models describing liquid chromatography retention and the solubility behavior of low-molecular mass guest molecules, controlled by supramolecular interactions with selected macrocycles. It should be noted that the reported phenomenon, specifically supramolecular complexes precipitation, may have a number of practical applications. This can be used to improve the efficiency and selectivity of planar and/or microfluidic systems. On the other hand, precipitation via host-guest interactions may be applied for highly selective water purification technological processes that will be designed for the removal of given organic micropollutants.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Studzińska, Sylwia, Feiyang Li, Michał Szumski, Bogusław Buszewski y Michael Lämmerhofer. "Cholesterol Stationary Phase in the Separation and Identification of siRNA Impurities by Two-Dimensional Liquid Chromatography-Mass Spectrometry". International Journal of Molecular Sciences 23, n.º 23 (29 de noviembre de 2022): 14960. http://dx.doi.org/10.3390/ijms232314960.

Texto completo

Resumen

The aim of this research was to develop a simple and efficient ion-pair reagent-free chromatographic method for the separation and qualitative determination of oligonucleotide impurities, exemplified by synthesis of raw products of the two single strands of patisiran siRNA. The stationary phases with mixed hydrophobic/hydrophilic properties (cholesterol and alkylamide) were firstly used for this purpose with reversed-phased high-performance liquid chromatography. Several different chromatographic parameters were tested for their impact on impurities separation: type, concentration, pH of salt, as well as organic solvent type in the mobile phase. The pH was the most influential factor on the separation and signal intensities in mass spectrometry detection. Finally, the optimized method included the application of cholesterol stationary phase, with mobile phase containing 20 mM ammonium formate (pH 6.5) and methanol. It allowed good separation and the identification of most impurities within 25 min. Since not all closely related impurities could be fully resolved from the main peak in this oligonucleotide impurity profiling, two-dimensional liquid chromatography was used for peak purity determination of the target oligonucleotides. The Ethylene Bridged Hybrid (BEH) Amide column in hydrophilic interaction liquid chromatography was applied in the second dimension, allowing additional separation of three closely related impurities.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Hua, LIU, ZHOU TingTing y FAN GuoRong. "Application of liquid chromatography-mass spectrometry in research on iridoid glycosides". Pharmaceutical Care and Research 2011, n.º 11 (27 de febrero de 2011): 45–49. http://dx.doi.org/10.5428/pcar20110114.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Krcmova, Lenka, Dagmar Solichova y Petr Solich. "Microplates in liquid chromatography – New solution in clinical research? – A review". Talanta 115 (octubre de 2013): 973–79. http://dx.doi.org/10.1016/j.talanta.2013.06.048.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Brandão, Pedro F., Armando C. Duarte y Regina M. B. O. Duarte. "Comprehensive multidimensional liquid chromatography for advancing environmental and natural products research". TrAC Trends in Analytical Chemistry 116 (julio de 2019): 186–97. http://dx.doi.org/10.1016/j.trac.2019.05.016.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Vekey, K., D. Edwards y L. F. Zerilli. "Liquid chromatography-mass spectrometry coupling and its application in pharmaceutical research". Journal of Chromatography B: Biomedical Sciences and Applications 488, n.º 1 (marzo de 1989): 73–85. http://dx.doi.org/10.1016/s0378-4347(00)82940-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Goyal, Sham S. "Applications of column liquid chromatography to inorganic analysis in agricultural research". Journal of Chromatography A 789, n.º 1-2 (noviembre de 1997): 519–27. http://dx.doi.org/10.1016/s0021-9673(97)00838-8.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Hartvig, Per y Bengt Långström. "Combination of positron emission tomography with liquid chromatography in neuropharmacologic research". Journal of Chromatography A 507 (mayo de 1990): 303–10. http://dx.doi.org/10.1016/s0021-9673(01)84207-2.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Gelpı́, Emilio. "Contributions of liquid chromatography–mass spectrometry to “highlights” of biomedical research". Journal of Chromatography A 1000, n.º 1-2 (junio de 2003): 567–81. http://dx.doi.org/10.1016/s0021-9673(03)00601-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Farzaliyev, V. M. y M. N. Aliyeva. "Feature analysis of vapor-phase chromatography of high boiler organic compounds". Azerbaijan Oil Industry, n.º 4 (15 de abril de 2020): 40–47. http://dx.doi.org/10.37474/0365-8554/2020-4-40-47.

Texto completo

Resumen

The paper presents the physical-chemical features of the vapor-phase chromatography method for the analysis of polar high boiler organic compounds. The application conditions of vapor-phase chromatography for the research of petrochemical synthesis products are analyzed. The mechanism of chromatographic seperation of compounds in the vapor-liquid-solid phase system is reviewed. The physical-chemical parameters of application of vapor-phase chromatography are provided. It is shown that liquid crystals can be used for the efficiency increase of the analysis of high boiler organic compounds as hard carriers. Thus, isomer compounds in the flow of water steam may be seperated. The usage of water-formamide mixture as a gas carrier enables the analysis of high boiler amine-based organic compounds. Natural, modified zeolite-containing tuff, diatoms and zeolites can be used as adsorbents and hard carriers in the separation of high boiler products of petrochemical synthesis.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Jin, Ri Jun, Chao Qun Chu, Xiao Ping Wang, Dong Hao Li y Xiang Fan Piao. "Research on Multifunctional Gas Chromatography Sample Pretreatment Apparatus". Applied Mechanics and Materials 347-350 (agosto de 2013): 3440–45. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.3440.

Texto completo

Resumen

Multifunctional gas chromatography sample pretreatment apparatus (hereinafter referred to as pretreatment apparatus), which is developed on the basis of gas purge micro-syringe extraction (GP-MSE) technique, is a gas chromatography (GC) sample pretreatment apparatus that integrates extraction, purification, concentration and predissociation. The quantitative and qualitative analysis results analyzed by GC-MS for volatile oil that extracted from the plant samples by steam distillation method and pretreatment apparatus, show that the volatile components extracted by the apparatus outnumber the ones extracted by steam distillation method clearly, and the content of major constituents extracted by the apparatus is higher. The apparatus have advantages of low consumption of agentia, short extraction time, high enrichment efficiency, simple structure, convenience in usage and low operating costs. The apparatus can be widely used in the areas of medicine, agriculture, food, quality control to the sample pretreatment of solid or liquid sample.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Abdu Hussen, Ali. "High-Performance Liquid Chromatography (HPLC): A review". Annals of Advances in Chemistry 6, n.º 1 (20 de junio de 2022): 010–20. http://dx.doi.org/10.29328/journal.aac.1001026.

Texto completo

Resumen

Today HPLC is widely applied for separations and purifications in a variety of areas including pharmaceuticals, biotechnology, environmental, polymer and food industries. It is accomplished by injection of a small amount of liquid sample into a moving stream of liquid (called the mobile phase) that passes through a column packed with particles of the stationary phase. The separation of a mixture into its components depends on different degrees of retention of each component in the column. HPLC is just one type of liquid chromatography, meaning the mobile phase is a liquid. Reversed-phase HPLC is the most common type of HPLC. The reversed-phase means the mobile phase is relatively polar, and the stationary phase is relatively non-polar. HPLC instrumentation includes a Solvent reservoir, pump, injector, column, detector, and integrator or acquisition and display system. The heart of the system is the column where separation occurs. The information that can be obtained using HPLC includes identification, quantification, and resolution of a compound. The major applications are in the area of Pharmaceuticals, food, research, manufacturing, forensics, and bio-monitoring of pollutants.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Petrova, Svetlana y Irina Maksimova. "Tokopherols in Okara (Soy Pulp): Highly Efficient Liquid Chromatography". Food Processing: Techniques and Technology 50, n.º 2 (27 de junio de 2020): 194–203. http://dx.doi.org/10.21603/2074-9414-2020-2-194-203.

Texto completo

Resumen

Introduction. Soy pulp, or okara, is a soy milk by-product. It contains a complex of valuable macro- and micronutrients, including fat-soluble vitamins. Recently, there has been a growing interest in replacing synthetic antioxidants with a mix of natural tocopherols. Soy beans and their by-products contain vitamin E and therefore can be used in food production, cosmetic, etc. Study objects and methods. The present research featured soy pulp. The content of tocopherols in the soy product was determined by high performance liquid chromatography using Sigma Aldrich standards and corresponding calibration dependencies. The research also involved spectrophotometry for determining tocopherols in standard solutions followed by chromatographic separation using fluorimetric detection. Results and discussion. To determine tocopherols in the okara, the test samples were treated with hexane. The filtered solution was exposed to low temperatures, after which the phases formed by centrifugation were separated. The samples were tested for all forms of tocopherols with the exception of β- and γ-forms. The chromatographic separation of the peaks of these forms was difficult due to the fact that their structural formulas were similar and differed only in the arrangement of methyl groups, i.e. the ortho- and paraposition. As a result, it was decided to determine the sum of the β- and γ-forms, which did not affect the objectivity of the analysis, since, according to published data, the content of β-tocopherol in soy products stays within 5%. Conclusion. The proposed method for sample preparation made it possible to improve the separation of the lipid fraction, which had a positive effect on the results of the analysis. The method also determined not only the quantitative, but also the qualitative content of tocopherols in the product. This reduced the risk of malfunctioning chromatographic equipment: the method proved more economical in terms of labor and reagent use. The obtained results corresponded to the existing scientific data on the content of tocopherols in soy products. The content of tocopherols in soy okara was 109 mg%.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Bao, Bo, Zhichao Wang, Dilantha Thushara, Achini Liyanage, Sanja Gunawardena, Zaiyong Yang y Shuangliang Zhao. "Recent Advances in Microfluidics-Based Chromatography—A Mini Review". Separations 8, n.º 1 (31 de diciembre de 2020): 3. http://dx.doi.org/10.3390/separations8010003.

Texto completo

Resumen

Microfluidics-based liquid chromatography is based on the miniaturization of the different types of liquid chromatography (LC) systems (e.g., affinity, adsorption, size exclusion, ion exchange) on a microchip to perform on-chip separation of different types of analytes. On-chip chromatography finds applications in genomics, proteomics, biomarker discovery, and environmental analysis. Microfluidics-based chromatography has good reproducibility and small sample consumption. However, the on-chip chromatography fabrication techniques are often more challenging to perform than conventional LC column preparation. Different research groups have attempted to develop different techniques to fabricate microfluidics-based LC systems. In this review, we will summarize the recent advances in microfluidics-based chromatography.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Aliaño-González, María, Marta Ferreiro-González, Gerardo Barbero, Miguel Palma y Carmelo Barroso. "Application of Headspace Gas Chromatography-Ion Mobility Spectrometry for the Determination of Ignitable Liquids from Fire Debris". Separations 5, n.º 3 (13 de agosto de 2018): 41. http://dx.doi.org/10.3390/separations5030041.

Texto completo

Resumen

A fast and correct identification of ignitable liquid residues in fire debris investigation is of high importance in forensic research. Advanced fast analytical methods combined with chemometric tools are usually applied for these purposes. In the present study, the Headspace Gas Chromatography-Ion Mobility Spectrometry (HS-GC-IMS) combined with chemometrics is proposed as a promising technique for the identification of ignitable liquid residues in fire debris samples. Fire debris samples were created in the laboratory, according to the Destructive Distillation Method for Burning that is provided by the Bureau of Forensic Fire and Explosives. Four different substrates (pine wood, cork, paper, and cotton sheet) and four ignitable liquids of dissimilar composition (gasoline, diesel, ethanol, and paraffin) were used to create the fire debris. The Total Ion Current (TIC) Chromatogram combined with different chemometric tools (hierarchical cluster analysis and linear discriminant analysis) allowed for a full discrimination between samples that were burned with and without ignitable liquids. Additionally, a good identification (95% correct discrimination) for the specific ignitable liquid residues in the samples was achieved. Based on these results, the chromatographic data from HS-GC-IMS have been demonstrated to be very useful for the identification and discrimination of ignitable liquids residues. The main advantages of this approach vs. traditional methodology are that no sample manipulation or solvent is required; it is also faster, cheaper, and easy to use for routine analyses.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Kulikov, Artem. "Development of micellar liquid and thin-layer chromatography." Zurnal Hromatograficnogo tovaristva 21, n.º 67 (11 de noviembre de 2021): 4–38. http://dx.doi.org/10.15407/zht2021.67.004.

Texto completo

Resumen

The review of the development of micellar high-performance liquid chromatography and micellar thin-layer chromatography is presented. The results of the research of the theoretical foundation and the organized solution usage as mobile phases for the analysis of plant and animal biological active substances, medicinal substances and drugs are demonstrated. The investigations had been carried out on the Chemical Metrology Department V.N. Karazin Kharkiv National University and in the State Enterprise “Ukrainian Scientific Pharmacopoeial Center for Quality of Medicines”.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Galvez, Luis, Mate Rusz, Michael A. Jakupec y Gunda Koellensperger. "Heart-cut 2DSEC-RP-LC-ICP-MS as a screening tool in metal-based anticancer research". Journal of Analytical Atomic Spectrometry 34, n.º 6 (2019): 1279–86. http://dx.doi.org/10.1039/c9ja00045c.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Liquid chromatography research"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros