DEDUCTIVE ELECTROCHEMICAL DETECTION FOR CAPILLARY ELECTROPHORESIS

A system has been developed for reductive electrochemical detection wi th capillary electrophoresis. The instrumental setup is much simpler t han that of reductive liquid chromatography/ electrochemistry (LCEC). The new method also possesses major advantages over LC-based methods i n terms of a less complicated deoxygenation system and shorter deoxyge nation times. Concentration detection Limits were similar to those rep orted for reductive LCEC. Mass detection limits for anthraquinone-2-ca rboxylic acid and (dinitrophenyl)-gamma-aminobutyric acid were 1.3 and 1.6 fmol, respectively, at a S/N of 2. The reproducibility of the sig nal for a 9.8-fmol anthraquinone-2-carboxylic acid injection yielded a relative standard deviation of 6.2%. The high selectivity of reductiv e electrochemical detection was demonstrated by the detection of mitom ycin C directly in human serum without prior extraction procedures.