Micellar electrokinetic chromatography (MEKC) is a chromatography technique used in analytical chemistry. It is a modification of capillary electrophoresis (CE), extending its functionality to neutral analytes, where the samples are separated by differential partitioning between micelles and a surrounding aqueous buffer solution.
Capillary electrophoresis (CE) is a family of electrokinetic separation methods performed in submillimeter diameter capillaries and in micro- and nanofluidic channels. Very often, CE refers to capillary zone electrophoresis (CZE), but other electrophoretic techniques including capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis and micellar electrokinetic chromatography (MEKC) belong also to this class of methods. In CE methods, analytes migrate through electrolyte solutions under the influence of an electric field. Analytes can be separated according to ionic mobility and/or partitioning into an alternate phase via non-covalent interactions. Additionally, analytes may be concentrated or "focused" by means of gradients in conductivity and pH.
Liquid chromatography–mass spectrometry (LC–MS) is an analytical chemistry technique that combines the physical separation capabilities of liquid chromatography with the mass analysis capabilities of mass spectrometry (MS). Coupled chromatography - MS systems are popular in chemical analysis because the individual capabilities of each technique are enhanced synergistically. While liquid chromatography separates mixtures with multiple components, mass spectrometry provides spectral information that may help to identify each separated component. MS is not only sensitive, but provides selective detection, relieving the need for complete chromatographic separation. LC-MS is also appropriate for metabolomics because of its good coverage of a wide range of chemicals. This tandem technique can be used to analyze biochemical, organic, and inorganic compounds commonly found in complex samples of environmental and biological origin. Therefore, LC-MS may be applied in a wide range of sectors including biotechnology, environment monitoring, food processing, and pharmaceutical, agrochemical, and cosmetic industries. Since the early 2000s, LC-MS has also begun to be used in clinical applications.
Electroextraction (EE) is a sample enrichment technique that focuses charged analytes from a large volume of one phase into a small volume of aqueous phase through the application of an electric current. The technique was originally developed as a separation technique for chemical engineering, but has since been coupled to capillary electrophoresis and liquid chromatography–mass spectrometry as a means of improving limits of detection, analysis time, and selectivity. The use of EE-CE has made capillary electrophoresis more applicable to use in the pharmaceutical industry.
Electrochromatography is a chemical separation technique in analytical chemistry, biochemistry and molecular biology used to resolve and separate mostly large biomolecules such as proteins. It is a combination of size exclusion chromatography and gel electrophoresis. These separation mechanisms operate essentially in superposition along the length of a gel filtration column to which an axial electric field gradient has been added. The molecules are separated by size due to the gel filtration mechanism and by electrophoretic mobility due to the gel electrophoresis mechanism. Additionally there are secondary chromatographic solute retention mechanisms.
Csaba Horváth was a Hungarian-American chemical engineer, particularly noted for building the first high-performance liquid chromatograph.
Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent from the first system is transferred onto the second column. Typically the second column has a different separation mechanism, so that bands that are poorly resolved from the first column may be completely separated in the second column. Alternately, the two columns might run at different temperatures. During the second stage of separation the rate at which the separation occurs must be faster than the first stage, since there is still only a single detector. The plane surface is amenable to sequential development in two directions using two different solvents.
Capillary electrophoresis–mass spectrometry (CE-MS) is an analytical chemistry technique formed by the combination of the liquid separation process of capillary electrophoresis with mass spectrometry. CE-MS combines advantages of both CE and MS to provide high separation efficiency and molecular mass information in a single analysis. It has high resolving power and sensitivity, requires minimal volume and can analyze at high speed. Ions are typically formed by electrospray ionization, but they can also be formed by matrix-assisted laser desorption/ionization or other ionization techniques. It has applications in basic research in proteomics and quantitative analysis of biomolecules as well as in clinical medicine. Since its introduction in 1987, new developments and applications have made CE-MS a powerful separation and identification technique. Use of CE-MS has increased for protein and peptides analysis and other biomolecules. However, the development of online CE-MS is not without challenges. Understanding of CE, the interface setup, ionization technique and mass detection system is important to tackle problems while coupling capillary electrophoresis to mass spectrometry.
Instrumental analysis is a field of analytical chemistry that investigates analytes using scientific instruments.
Leslie Stephen Ettre was a Hungarian-American analytical chemist and scientist who was known for his contributions to the field of chromatography, in particular open-tubular gas chromatography, as well as to documentation of the history of chromatography.
Edward S. Yeung is a Chinese-American chemist who studies spectroscopy and chromatography. Yeung is a Distinguished Professor Emeritus at Iowa State University. He was elected as a Fellow of the American Association for the Advancement of Science. He was a founding co-editor of the Annual Review of Analytical Chemistry from 2008 to 2014 and has served on the editorial committees of a number of other journals.
Richard Dale Smith is a chemist and a Battelle Fellow and Chief Scientist within the Biological Sciences Division, as well as the Director of Proteomics Research at the Pacific Northwest National Laboratory (PNNL). Dr. Smith is also Director of the NIH Proteomics Research Resource for Integrative Biology, an adjunct faculty member in the chemistry departments at Washington State University and the University of Utah, and an affiliate faculty member at the University of Idaho and the Department of Molecular Microbiology & Immunology, Oregon Health & Science University. He is the author or co-author of approximately 1100 peer-reviewed publications and has been awarded 70 US patents.
Marek Andrzej Trojanowicz is a Polish chemist, professor of chemical sciences with specialization in analytical chemistry, academic staff member, and head of the Laboratory for Flow Analysis and Chromatography, University of Warsaw, Poland.
Walter Goodrich Jennings was an American chemist, educator and entrepreneur. He was co-founder of J&W Scientific, which became the world's largest supplier of fused silica columns; the company was purchased by Agilent Technologies in 2000.
Daniel Wayne Armstrong is an American chemist who specializes in separation science, chiral molecular recognition, bioanalytic analysis, mass spectrometry and colloid chemistry. He is the Robert A. Welch Distinguished Professor at the University of Texas at Arlington. He has authored ~ 750 publications including 35 book chapters, a book, and holds over 35 patents on separation technologies. He was an associate editor for the prestigious American Chemical Society journal Analytical Chemistry and is a member of the national Academy of Inventors. Armstrong has given over 560 invited seminars worldwide at international conferences, universities and corporations. His research and patents formed the basis for two companies: Advanced Separation Technologies, Inc; which was acquires by Sigma-Aldrich Corporation in 2006 and AZYP, LLC in Arlington, TX. His published work has been cited over 46,200 times and his h-index is 109. He is believed to have mentored more graduate level analytical chemists than any living scientist.
Milos Vratislav Novotny is an American chemist, currently the Distinguished Professor Emeritus and Director of the Novotny Glycoscience Laboratory and the Institute for Pheromone Research at Indiana University, and also a published author. Milos Novotny received his Bachelor of Science from the University of Brno, Czechoslovakia in 1962. In 1965, Novotny received his Ph.D. at the University of Brno. Novotny also holds honorary doctorates from Uppsala University, Masaryk University and Charles University, and he has been a major figure in analytical separation methods. Novotny was recognized for the development of PAGE Polyacrylamide Gel-filled Capillaries for Capillary Electrophoresis in 1993. In his years of work dedicated to analytical chemistry he has earned a reputation for being especially innovative in the field and has contributed a great deal to several analytical separation methods. Most notably, Milos has worked a great deal with microcolumn separation techniques of liquid chromatography, supercritical fluid chromatography, and capillary electrophoresis. Additionally, he is highly acclaimed for his research in proteomics and glycoanalysis and for identifying the first mammalian pheromones.
John Michael Ramsey is an American analytical chemist at the University of North Carolina at Chapel Hill. He currently holds the position of Minnie N. Goldby Distinguished Professor of Chemistry. His current research with the university focuses on microscale and nanoscale devices such as microchip electrospray, microscale Ion trap mass spectrometers, and microfluidic point of care devices. He is ranked #2 in the "Giants of Nano" field on The Analytical Scientist Power List.
Peter Nemes, Ph.D., is a Hungarian-American chemist, who is active in the fields of bioanalytical chemistry, mass spectrometry, cell/developmental biology, neuroscience, and biochemistry.
Robert (Bob) Kennedy is an American chemist specializing in bioanalytical chemistry including liquid chromatography, capillary electrophoresis, and microfluidics. He is currently the Hobart H. Willard Distinguished University Professor of Chemistry and the Chair of the Department of Chemistry at the University of Michigan. He holds joint appointments with the Department of Pharmacology and Department Macromolecular Science and Engineering. Kennedy is an Associate Editor of Analytical Chemistry.
Apryll Marie Stalcup is an Irish chemist who is Professor and Director of the Irish Separation Science Cluster at Dublin City University. She was awarded the 2015 American Microchemical Society Benedetti Pichler Award and named in the 2016 Power List of the Top 50 Women Analytical Scientists worldwide. Her research considers surface-confined ionic liquids and separation science.
