title: Simple GC-FID method development and validation for determination of alpha-tocopherol (vitamin E) in human plasma.
abstract: This paper describes the development and validation of a novel GC-FID method for the determination of alpha-tocopherol concentration in human plasma which does not requires derivatization. The standard solutions and the plasma working solutions were prepared in absolute ethanol. To determine the concentration of alpha-tocopherol in human plasma, an aliquot of the plasma sample was deproteinized with ethanol. alpha-tocopherol was extracted with a mixture of hexane and dichloromethane (9:1). GC separation was performed using a HP-5 capillary column. Nitrogen was used as carrier gas at a flow-rate of 2 ml min(-1). Calibration curves were linear over the concentration range 1-30 microg ml(-1) (for standard solutions and solutions without endogenous alpha-tocopherol in plasma) and 5-34 microg ml(-1) (for solutions with endogenous alpha-tocopherol in plasma). Absolute recovery, precision, sensitivity and accuracy assays were carried out. The analytical recovery of alpha-tocopherol from plasma averaged 97.44%. The limit of quantification (LOQ) and the limit of detection (LOD) of method for standard samples were 0.35 microg.ml(-1) and 0.30 microg.ml(-1), respectively. Within-day and between-day precision, expressed as the relative standard deviation (RSD) were less than 4%, and accuracy (relative error) was better than 8%. This novel method, developed and validated in our laboratory, could be successfully applied to the in-vivo determination of alpha-tocopherol. The endogenous alpha-tocopherol amounts in blood of twelve healthy volunteers with no vitamin drug usage were measured with this method.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Ataturk University, 25240, Erzurum, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Demirkaya
authors.forename: Yucel
authors.initials: Y
authors.lastname: Kadioglu
mesh_terms: D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D004355:Drug Stability; D005260:Female; D005410:Flame Ionization / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D024502:alpha-Tocopherol / Q000097:blood* / Q000592:standards
chemical_list: D024502:alpha-Tocopherol