Capillary electrophoresis coupled with 1,1′-thiocarbonyldiimidazole derivatization for the rapid detection of total homocysteine and cysteine in human plasma

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Analytical technologies in the biomedical and life sciences, 2015-11, Vol.1004, p.30-36
• Main Authors: Ivanov, Alexander Vladimirovich, Virus, Edward Danielevich, Luzyanin, Boris Petrovich, Kubatiev, Aslan Amirkhanovich
• Format: Article
• Language: English
• Subjects: 1,1′-Thiocarbonyldiimidazole; Capillary electrophoresis; Centrifugation; Chromatography, High Pressure Liquid; Cysteine; Cysteine - blood; Electrophoresis, Capillary - methods; Homocysteine; Homocysteine - blood; Humans; Imidazoles - chemistry; Spectrophotometry, Ultraviolet
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2015.09.036

•A new CE–UV method for quantification of homocysteine, cysteine and their ratio in plasma was validated.•The time of analysis was 6min.•Specific derivatization of aminothioles using 1,1′-thiocarbonyldiimidazole.•The method could be used for clinical researches. A simple and rapid approach is described for the determination of total plasma cysteine and homocysteine using capillary electrophoresis. Human plasma samples were reduced with dithiothreitol and then processed with 1,1′-thiocarbonyldiimidazole in acetonitrile. After centrifugation, the sample supernatant was injected directly into a capillary by applying negative voltage and analytes were stacked after alkaline post-injection. Using a 50μm i.d. silica capillary of 35cm total length, filled with 0.1M triethanolamine, 0.15M formic acid, and 50μM hexadecyltrimethylammonium bromide (pH 3.9), we reached a limit of quantification of 2.5μM for homocysteine. Accuracy was 94.7–105.1%, intra- and inter-day imprecisions were