Determination of the main low molecular weight aminothiols in blood plasma using HPLC-MS method

Abstract

Herein we describe the new sensitive method using the high-performance liquid chromatographymass-spectrometry (HPLC-MS) assay with electrospray ionization (ESl) for the quantitative detection of total aminothiols (cysteine, homocysteine, cysteine-glycine, and glutathione) in plasma. The disulfide bonds were reduced by dithiothreitol (DTT) followed by its derivatization by N-ethylmaleimide (NEM) to raise the thiol group resistance to an oxidation due to its modification as well as simultaneous to raise ten-fold in the MS detection receptiveness. The calibration curves were linear over the concentration range of 2–50 ^M for homocysteine and glutathione, of 4–100 ^M for cysteine-glycine, and o f20–00 ^M for cysteine. The coefficients of variation for the thiols detections were about 10%. Our proposed approach may be used as the alternative method for the simultaneous detection of the main low molecular weight aminothiols.