Simultaneous determination of cysteine, cystine and 18 other amino acids in various matrices by high-performance liquid chromatography

An extraction protocol and a reversed-phase high-performance liquid chromat ographic method for the simultaneous determination of cysteine, cystine and 18 other amino acids in biological and vegetable samples are described. Am ong the different methods proposed for amino acid determination, phenylisot hiocyanate was used as the reagent for derivatization. Chromatograms obtain ed in the analysis of standard solutions and actual samples are reported, t ogether with regression equation, correlation coefficient (>0.999 for all), limit of detection and recoveries (between 86 and 102% for all the examine d matrices) for each amino acid. Practical protocol and method applications in normal patients and patients affected by different pathologies, and in algal products are discussed. (C) 1999 Published by Elsevier Science BN. Al l rights reserved.