High-performance liquid chromatography of sulfur-containing amino acids and related compounds with amperometric detection at a modified electrode.
Organic disulfides generally are not oxidized at bare electrodes under conditions that are suited to routine amperometric detection, and thiols are typically oxidized in a manner that leads to partial blockage of the surface. Modification of a carbon electrode with a film of Ru(III,IV) oxide stabilized with cyanocross-links permits the amperometric detection of cystine, cysteine, glutathione, methionine, and glutathione disulfide under conditions compatible with their chromatographic separation on a strong cation-exchange column. Detection limits of 0.2-0.6 microM and linear dynamic ranges of at least 1-50 microM were obtained. The electrode was stable for at least 11 days with a pH 1 citrate, phosphate mobile phase.
Cox
J A
JA
Department of Chemistry, Miami University, Oxford, OH 45056.
Dabek-Zlotorzynska
E
E
D000603:Amino Acids, Sulfur / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D004566:Electrodes
D000603:Amino Acids, Sulfur