title: Quantification of homocysteine and cysteine by derivatization with pyridoxal 5'-phosphate and hydrophilic interaction liquid chromatography.
abstract: A simple and rapid assay using pyridoxal 5'-phosphate (PLP) as a derivatizing reagent was developed for the simultaneous determination of homocysteine (Hcy) and cysteine (Cys) in human plasma. Derivatization with PLP affords UV-absorbing tetrahydrothiazine and thiazolidine derivatives of Hcy and Cys, respectively. Separation of these derivatives was achieved in 5 min using a hydrophilic interaction liquid chromatography, followed by UV detection at 330 nm. Linearity in detector response was observed over the range of 0.25-20 μM for Hcy and 10-300 μM for Cys. The limit of quantification (LOQ) values for Hcy and Cys were 0.25 and 2.5 μM, respectively. The method was successfully applied to plasma samples donated by apparently healthy volunteers.
authors.affiliation: Faculty of Chemistry, Department of Environmental Chemistry, University of Łódź, 163 Pomorska Str., 90-236, Łódź, Poland. glowar@uni.lodz.pl.
authors.forename: Rafał
authors.initials: R
authors.lastname: Głowacki
authors.affiliation: Faculty of Chemistry, Department of Environmental Chemistry, University of Łódź, 163 Pomorska Str., 90-236, Łódź, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Stachniuk
authors.affiliation: Faculty of Chemistry, Department of Environmental Chemistry, University of Łódź, 163 Pomorska Str., 90-236, Łódź, Poland.
authors.forename: Kamila
authors.initials: K
authors.lastname: Borowczyk
authors.affiliation: Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA.|Department of Biochemistry and Biotechnology, University of Life Sciences, 60-637, Poznań, Poland.|Institute of Bioorganic Chemistry, 61-704, Poznań, Poland.
authors.forename: Hieronim
authors.initials: H
authors.lastname: Jakubowski
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003545:Cysteine / Q000032:analysis / Q000097:blood*; D006710:Homocysteine / Q000032:analysis / Q000097:blood*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D011732:Pyridoxal Phosphate / Q000737:chemistry; D015203:Reproducibility of Results
chemical_list: D006710:Homocysteine; D011732:Pyridoxal Phosphate; D003545:Cysteine
keywords: Cysteine; Derivatization; Homocysteine; Hydrophilic interaction liquid chromatography; Plasma; Pyridoxal 5'-phosphate