Showing papers in "Journal of Chromatography A in 1992"

TL;DR: In this paper, a chip-like structure for capillary electrophoresis is presented, which is based on the photolithographic technique for structures in the micrometer range.

TL;DR: In this article, a simple model for the separation of pairs of enantiomeric molecules in capillary electrophoresis is presented, which shows that the degree of separation depends on the concentration of chiral selector, and that there is an optimum concentration.

TL;DR: Applications shown include kinetic measurements, binding site analysis and concentration determination, which does not require molecular labels for detection, can measure mass changes down to 10 pg/mm2.

TL;DR: A method for screening genotoxic heterocyclic aromatic amines in cooked foods using solid-phase extraction and high-performance liquid chromatography with ultraviolet and fluorescence detection is described.

TL;DR: The concurrent determination of free amino acid enantiomers and non-chiral amino acids in rat brain and serum was accomplished by high-performance liquid chromatography with fluorimetric detection after derivatization with N-tert.-butyloxycarbonyl-L-cysteine and o-phthaldialdehyde to support the presence of D-serine in adult brain tissues.

TL;DR: Amino acids were determined by precolumn derivatization with diethyl ethoxymethylenemalonate and reversed-phase high-performance liquid chromatography with spectrophotometric detection with results equivalent to those obtained by conventional ion-exchange-based amino acid analysis.

TL;DR: This paper describes an ultramicro method for achieving enzyme assays using enzyme saturating concentrations of substrate, coenzyme when appropriate, and running buffer to fill a deactivated fused-silica capillary in a capillary zone electrophoresis apparatus.

TL;DR: In this article, two strategies for the isotachophoretic preconcentration of samples were evaluated using a standard protein mixture as an example, and a coupled column system was examined which, in principle, provides a higher degree of freedom in the selection of capillary zone electrophoretic running conditions and the possibility of injection of higher sample volumes.

TL;DR: The combined method SPME-GC-IT-MS, using fibers coated with a 100-microns polydimethylsiloxane coating, showed a limit of quantitation (LOQ) of 50 pg/ml benzene in water, which exceeds the requirements of both the United States Environmental Protection Agency method 524.2 and the Ontario Municipal/Industrial Strategy for Abatement program.

TL;DR: In this paper, it was shown that the addition of methanol to the buffer can lead to either an increase or decrease in separation of propranolol enantiomers.

TL;DR: In this paper, a theoretical description of the sample self-stacking effect in zone electrophoresis is given, which applies to samples that contain a high concentration of an ionic component with high mobility and like charge.

TL;DR: CApillary zone electrophoresis was tested for its suitability for studying protein-drug binding and frontal analysis appeared to be the preferred method.

TL;DR: The potential of the microextraction technique for the analysis of flavor and fragrance compounds in non-caffeinated beverages is demonstrated, and no solvents or class-fractionation steps are required and the method has good potential for automation.

TL;DR: This review surveys the problems arising from the release of PCBs into the environment from the point of view of the analytical chemist and pays prominent attention to congener-specific analyses of "toxic" congeners using high-resolution gas chromatography and to toxicity-assessing biological methods.

TL;DR: In this article, the applicability of electroendosmotic flow as an elution system in reversed-phase chromatography with packed capillaries was investigated, and it was shown that very high performance could be achieved.

TL;DR: In this article, a reversed-phase high-performance liquid chromatographic method has been developed for the separation and determination of the flavonoids found in the leaves and therapeutically used extracts of Ginkgo biloba.

TL;DR: In this article, the reproducible separation of fifteen metal cations was completed in 8 min. The detection system showed a linear relationship between peak area and analyte concentration, and complexing compounds were added to the electrolyte to maximize selectively the differences in the apparent mobilities of the cations and enhance the separations.

TL;DR: In this article, an on-column joint utilizing Nafion tubing for the isolation of the electrical circuit from the detection end of a capillary zone electrophoresis system is described.

TL;DR: A highly sensitive laser-induced (LIF) detection scheme for native, tryptophan- or tyrosine-containing proteins in capillary electrophoresis (CE) has been demonstrated and the practical performance and blueprint of an easily constructed, rugged, compact and user-friendly LIF detector for CE are shown.

TL;DR: This paper reviews the derivatization techniques, capillary columns and stationary phases commonly used in the gas chromatography of fatty acids in food.

TL;DR: Frontal analysis performed with the highly selective affinity system involving the adsorption of human polyclonal immunoglobulin G onto Protein A Sepharose Fast Flow indicate that the advertisersorption performance of the expanded bed is similar to that achieved when the same amount of adsorbent is used in a packed configuration at the same volumetric flow-rate.

TL;DR: In this paper, the fundamental characteristics of microemulsion electrokinetic chromatography (MEEKC) were studied in comparison with micellar EKF (MEKC) and showed that MEEKC showed a stronger affinity to nonpolar compounds than the SDS micelle.

TL;DR: Maltodextrins were found to be effective as chiral electrolyte modifiers to perform direct, rapid separations by capillary electrophoresis of racemic mixtures of 2-arylpropionic acid non-steroidal anti-inflammatory compounds and coumarinic anticoagulant drugs, and also diastereomeric cephalosporin antibiotics.

TL;DR: In this article, the authors describe the optimized separations of several types of samples considered until recently to be beyond the capabilities of capillary electrophoresis, including reactive anions and trace ion analysis with detection limits in the low parts per trillion (1012) range.

TL;DR: The technique is particularly useful for metabolic studies of the chain elongation and further desaturation of PUFAs by separately incubating isolated cells with [1-14C]18:2(n - 6) and [1 -14C)18:3 (n - 3).

TL;DR: The application of capillary electrophoresis-mass spectrometry (CE-MS) to the analysis of compounds of concern to the aquaculture industry is reported and the ability to distinguish isomeric compounds based on their different migration and fragmentation characteristics using CE-MS-MS is demonstrated.

TL;DR: The experiments show that the poly(glycidyl methacrylate) discs used are especially suitable for the isolation of proteins and other biopolymers which occur in a diluted state in complex mixtures.

TL;DR: High-performance liquid chromatography (HPLC) is becoming a standard method in vitamin assay, especially for routine work, resulting in very sensitive methods, even when simple UV detection is employed.

TL;DR: In this paper, the simulated moving bed adsorption (SMBA) technique was applied to optical resolution using eight columns packed with chiral stationary phases, and it was concluded that the former is better from the point of productivity and solvent recovery.

TL;DR: In this paper, the authors used thin-layer chromatography (TLC), high-performance liquid chromatography, and gas chromatography for the determination of safranal using a Shimadzu 5% SE-30 column with 20% acetonitrile in water as the eluent.