Comparison of anion-exchange and ion-modified reversed-phase liquid chromatography for the determination of S-sulfocysteine.
A dual Hg-Au amalgam electrode is used to detect S-sulfocysteine (SSC) in this study. There exist two main components in the acetonitrile (ACN) rat brain extracts, namely, Cl- and GSSG (oxidized glutathione), that are active in our detection system (GSH is not extracted in ACN). Two strong anion-exchange columns from different companies were used to separate the samples under different conditions, but SSC and Cl- were not separated at the optimum detection pH of 5.2. The signal from Cl- was greatly decreased by lowering the potential at the downstream electrode, though it cannot be completely eliminated. While a silver cartridge removed Cl- from micromoles to several millimoles without any negative effect on the SSC signal in aqueous standards, a large negative peak which interferes with SSC detection was unfortunately introduced when a silver cartridge was applied to brain tissue samples. However, SSC and Cl- in the samples are successfully separated by ion-modified reversed-phase LC in acetate buffer at the optimum detection pH (5.2). The separation conditions are 20 mM acetic acid, 2% methanol, 0.5 mM cetyltrimethylammonium p-toluene sulfonate (CTMA) (pH 5.2). Most importantly, the sensitivity of SSC under the optimum separation conditions is not sacrificed. The detection limit is 8 nM (20 microl injected).
Xia
W
W
Chevron Science Center, University of Pittsburgh, PA 15260, USA.
Sandberg
M
M
Weber
S G
SG
D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000737:chemistry; D002712:Chlorides; D002852:Chromatography, Ion Exchange / Q000379:methods* / Q000592:standards; D002853:Chromatography, Liquid / Q000379:methods* / Q000592:standards; D003545:Cysteine / Q000031:analogs & derivatives* / Q000032:analysis / Q000592:standards; D003553:Cystine / Q000592:standards; D004563:Electrochemistry; D005978:Glutathione / Q000592:standards; D019803:Glutathione Disulfide / Q000592:standards; D051381:Rats
D002712:Chlorides; D003553:Cystine; C011119:S-sulphocysteine; D005978:Glutathione; D003545:Cysteine; D019803:Glutathione Disulfide