title: Capillary electrophoresis coupled with 1,1'-thiocarbonyldiimidazole derivatization for the rapid detection of total homocysteine and cysteine in human plasma.
abstract: 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 <2.5 and <3%, respectively. The total analysis time was 6min. Furthermore, liquid-phase extraction with isopropanol led to a fourfold increase in sensitivity.
authors.affiliation: Federal State Budgetary Scientific Institution "Institute of General Pathology and Pathophysiology", Baltiyskaya Str., 8, Moscow 125315, Russia. Electronic address: Ivanov_av82@mail.ru.
authors.forename: Alexander Vladimirovich
authors.initials: AV
authors.lastname: Ivanov
authors.affiliation: Federal State Budgetary Scientific Institution "Institute of General Pathology and Pathophysiology", Baltiyskaya Str., 8, Moscow 125315, Russia.
authors.forename: Edward Danielevich
authors.initials: ED
authors.lastname: Virus
authors.affiliation: Federal State Budgetary Scientific Institution "Institute of General Pathology and Pathophysiology", Baltiyskaya Str., 8, Moscow 125315, Russia.
authors.forename: Boris Petrovich
authors.initials: BP
authors.lastname: Luzyanin
authors.affiliation: Federal State Budgetary Scientific Institution "Institute of General Pathology and Pathophysiology", Baltiyskaya Str., 8, Moscow 125315, Russia.
authors.forename: Aslan Amirkhanovich
authors.initials: AA
authors.lastname: Kubatiev
mesh_terms: D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000097:blood*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007093:Imidazoles / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: C000607451:1,1'-thiocarbonyldiimidazole; D007093:Imidazoles; D006710:Homocysteine; D003545:Cysteine
keywords: 1,1′-Thiocarbonyldiimidazole; Capillary electrophoresis; Cysteine; Homocysteine