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Preliminary Study on Reverse Pulse Amperometric Detection in Capillary Electrophoresis for Simultaneous Determination of Cysteine and Cystine
Author(s) -
Hsi TaiSung,
Chuang MayYin
Publication year - 1998
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.199800125
Subject(s) - chemistry , capillary electrophoresis , amperometry , microelectrode , detection limit , cystine , oxidizing agent , chromatography , cysteine , analytical chemistry (journal) , electrode , electrochemistry , biochemistry , organic chemistry , enzyme
Abstract Simultaneous determination of cysteine (RSH) and cystine (RSSR), two important sulfur‐containing amino acids, in capillary electrophoresis (CE) has been an analytical task. Dual‐microelectrode amperometric detection seems to be a good scheme, but significant difficulty in electrode construction and poor detection limit for RSSR determination remain major short‐comings. In reverse pulse amperometric (RPA) detection, the applied potentials are repeatedly pulsed back and forth between the reducing initial potential (e.g., E i = −1.4 V) and the oxidizing final potential (e.g., E f = 0.0 V) at a single, gold‐mercury amalgam (Au/Hg) microelectrode. At E i , RSSR is reduced to RSH which causes catalytical oxidation of the Au/Hg amalgam microelectrode when the potential is pulsed to E f . The resulting anodic current is then recorded. Therefore, by using RPA detection after CE separation, RSH and RSSR can be simultaneously determined.