Showing papers in "Journal of Chromatography A in 1988"

TL;DR: In this article, the incorporation of a complexing agent within a polyarcylamide gel column provides a general means of manipulating the selectivity of a capillary electrophoresis separation.

TL;DR: In this article, a number of volatile racemic solutes belonging to different classes of compounds have been resolved on permethylated β-cyclodextrin in OV-1701 on high-resolution glass open-tubular columns.

TL;DR: A high-performance liquid chromatographic system, which uses a weak cation exchanger (PolyCATA) together with Bis-Tris buffer (pH 6.47-7.0) and sodium acetate gradients, is described and allows the separation of minor foetal haemoglobin (HbF) variants and the simultaneous quantitation of HbF and glycated HbA.

TL;DR: In this article, the effects of temperature on the performance of liquid chromatography of large molecules at high temperatures are investigated. But the authors focus on the effect of temperature in terms of speed and efficiency.

TL;DR: The equivalent chain length of the methyl ester derivatives of synthetic unsaturated fatty acids in addition to many from natural sources have been determined by gas chromatography (GC) with modern wall-coated open-tubular columns of fused silica coated with Carbowax 20MTM, Silar 5CPTM, CP-Sil 84TM and a 5% phenyl-methyl silicone as mentioned in this paper.

TL;DR: Ion evaporation resulting from the ion spray liquid chromatography-mass spectrometry interface exhibits primarily molecular weight information as singly and multiply charged ions and is shown to be a sensitive and mild ionization method for peptides.

TL;DR: A total system for the analysis and isolation of microcystins was established and the adsorptive powers of three commercially available C18 cartridges successfully applied to the clean up of three of the toxins.

TL;DR: Molecular species representative of the wide range of triacylglycerols occurring in nature, ranging from relatively saturated fats such as that from sheep adipose tissue through polyunsaturated seed oils, have been resolved by high-performance liquid chromatography in the silver ion mode.

TL;DR: The new cation exchanger is quite promising as a supplement to RPC for general peptide chromatography, with modest mixed-mode effects, allowing the resolution of peptides having identical charges at a given pH.

TL;DR: The fast isolation procedure made it possible to determine the reduced and oxidized forms of Co Q10 in plasma and Quantitative recoveries were obtained for all the analytes studied.

TL;DR: The biochemistry and physiology underlying the use of such analyses is examined to guide sampling of the appropriate body fluid at a relevant time and to avoid oversimplified interpretation of results as well as unnecessary arguments.

TL;DR: A simultaneous micro-determination of nicotinamide and its major metabolites, N1-methyl-2-pyridone-5-carboxamide (2-py) and N1 -methyl-4-pyrimidine-3-car boxamide (4-py), by high-performance liquid chromatography is described, applied to the analysis of rat and human urines.

TL;DR: Evidence is presented supporting the existence of ion-pairing equilibria simultaneously accompanied by micellar solubilization in capillary zone electrophoresis for cationic and non-ionic catechols.

TL;DR: Using β-cyclodextrin and heptakis(2,6-di-O-methyl)-β-cyclodextrin as additives to the leading electrolyte in isotachophoresis, the complete chiral resolution of pseudoephedrine antipodes was achieved, but ephedrine enantiomers were not separated.

TL;DR: In this paper, the authors augment l'hydrophobicite des cyclodextrines par alkylation, on utilise ces derives comme phases liquides for la chromatographie gaz capillaire.

TL;DR: Supercritical fluid chromatography and supercritical fluid extraction have been coupled to provide on-line evaluation of a dynamic extraction procedure and the simultaneous removal and analysis of representative sulfonylureas, their precursors and metabolites from complex matrices was accomplished.

TL;DR: The method was highly reproducible, as shown by the results obtained by automated analysis of cyanogen bromide fragments of lysozyme at high speed, and compares favorably with that of maps obtained by standard reversed-phase HPLC methods, which require much longer analysis times.

TL;DR: A post-capillary fluorescence detection scheme for capillary zone electrophoresis using o-phthaldialdehyde (OPA) as the tagging reagent is described in this article.

TL;DR: In this article, the authors describe the optimization of the column for their initial work on reversed-phase HPLC separations, and show that polystyrene packings having particle diameters of 5 μm and pore diameters with 300 A are generally superior in terms of resolution, sample recovery and minimization of ghosting.

TL;DR: Combinations of modern techniques, such as immunoaffinity chromatography or immobilized-metal affinity chromatography, with classical techniques seem to be suitable for large-scale recovery of recombinant proteins.

TL;DR: Seven water-soluble vitamins were determined simultaneously by micellar electrokinetic capillary chromatography with UV detection and five principal constituents of a vitamin injection were determined with relative standard deviations of less than 2.1%.

TL;DR: Multivalent ion exchange is proposed as a generally applicable formalism to describe the non-linear chromatographic adsorption of biopolymers and the inapplicability of the Langmuir isotherm in this region is demonstrated.

TL;DR: At the pH extremes of 2 and 11 peak sharpness and protein mass recovery were found to be superior to those obtained with neutral eluents, and Analytical information about peptide and protein mixtures could be enhanced by using eluent at the pH Extremes.

TL;DR: Partially substituted hydroxypropyl-beta-cyclodextrin and hydroxyethyl- beta-cyclodesxtrin proved to be effective chiral mobile phase additives (CMAs) for the thin-layer chromatographic (TLC) resolution of racemic benzyl-2-oxazolidinone, 5-phenylhydantoin, mephenytoin and several dansyl and beta-naphthylamide amino acids.

TL;DR: Reversed-phase high-performance liquid chromatography and pre-column derivatization with 1-fluoro-2,4-dinitrophenyl-5-L-alanine amide (Marfey's reagent) were used for monitoring racemization in peptides, amino acids and their derivatives by separation of optical isomers of amino acids.

TL;DR: From the retention behaviour of these peptide polymers on C4, C8 and C18 stationary phases under gradient elution conditions, the effect of polypeptide chain length and hydrophobicity on peptide retention is established and the utility of retention time prediction for peptides containing up to 50 residues is extended by introducing a peptide chain-length correction.