Plasma total homocysteine and other thiols analyzed by capillary electrophoresis/laser-induced fluorescence detection: Comparison with two other methods

We present a new analytical method for thiol quantification in plasma, base d on the use of capillary electrophoresis (CE) and laser-induced fluorescen ce (LiF) to analyze 6-iodoacetamidofluorescein derivatives. Quantitative re sults of homocysteine, glutathione, cysteinylglycine, and cystationine are presented. A comparison of the quantitation of homocysteine in plasma, usin g high performance liquid chromatography/fluorscence detection and fluoresc ence polarization immunoassay is proposed. The results indicate that these techniques for plasma total homocysteine (tHcy) determination can be used i nterchangeably. The major advantage of CE-LiF is that it can quantitate the thiols in one run while keeping the price of consumables reasonable.