A Method for the Determination of Methionine in Human Serum by High-Performance Liquid Chromatography with Electrochemical Detection

Abstract

We have found remarkable enhancement of electrochemical response for the analysis of methionine by use of a glassy carbon electrode preanodized in a 0.2 M phosphate buffer (KH₂PO₄?KOH, pH 6.5) at +1.9 V vs. Ag/AgCl for 2 min. On the basis of this finding, we have developed a method for the determination of methionine in human serum by reversed-phase high-performance liquid chromatography with electrochemical detection using the electrochemically pretreated glassy carbon electrode. The minimum detectable quantity of methionine has been found to be about 1 ng.