Redox-based chemiluminescence assay of aminothiols in human urine: A fundamental study

The biological importance of aminothiols is well recognized with the concentration of these compounds within biological fluids such as plasma and urine functioning as valuable biomarkers in a number of clinical circumstances and a wide variety of diseases. Herein, for the first time, chromatographic coupled chemiluminescent assay was used for simultaneous determination of aminothiols in human urine. The method exploits nucleophilic nature of aminothiols to form adducts in the existence of quinones. The released adducts retain the redox-cycling capability of parent quinones and able to liberate reactive oxygen species (ROS) when come in contact with dithiothreitol (DTT). Strong glow is released upon reaction of ROS with luminol. The method succeeded to determine aminothiols in human urine after solid phase extraction achieving good linearity and high sensitivity shown by low limit of detection (LOD) ranged from 3.8 to 16 (fmol per injection).