Pre-column derivatization high-performance liquid chromatographic method for determination of cysteine, cysteinyl-glycine, homocysteine and glutathione in plasma and cell extracts

A sensitive high-performance liquid chromatographic method for quantification of sulphydryl and disulfide amino acids in human plasma using ultra violet spectrophotometric detection was developed. Precolumn derivatization with 5,5 ' -dithio-bisnitrobenzoic acid (DTNB) and an optional pre-derivatization reaction with dithiothreitol allowed both quantitative reduction of disulfides for measurement of total amino acid levels and the measurement of the reduced forms, A dynamic range of 500 nmol/1-750 mu mol/l allowed the major analytes of interest to be quantified in plasma without sample dilution. The assay is a sensitive and precise method for the determination of sulphydryl and disulfide amino acids in plasma and cell extracts. (C) 2001 Elsevier Science B.V. All rights reserved.