title: Ascorbic acid determination with an automated enzymatic procedure.
abstract: Given the widespread interest in antioxidant nutrients, we have developed a new procedure that will permit the automated determination of plasma ascorbic acid (AA) concentration with a Roche Fara centrifugal analyzer. After the deproteinization of plasma with metaphosphoric acid, AA is oxidized to dehydroascorbic acid by AA oxidase. The product is coupled to o-phenylenediamine to produce a chromophore for which the absorbance is measured at 340 nm. The procedure allows much faster throughput than conventional HPLC methods while yielding results that correlate well and provide improved precision. Linearity extends beyond the reference range of 26.1-84.6 micromol/L, and severe hemolysis is the only interference identified.
authors.affiliation: Department of Laboratory Medicine, Harborview Medical Center and University of Washington, Seattle 98104-2499, USA.
authors.forename: W
authors.initials: W
authors.lastname: Lee
authors.forename: S M
authors.initials: SM
authors.lastname: Roberts
authors.forename: R F
authors.initials: RF
authors.lastname: Labbe
mesh_terms: D000328:Adult; D001204:Ascorbate Oxidase / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D001322:Autoanalysis; D002851:Chromatography, High Pressure Liquid; D003683:Dehydroascorbic Acid / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D010655:Phenylenediamines; D011786:Quality Control; D012016:Reference Values; D012680:Sensitivity and Specificity; D013053:Spectrophotometry
chemical_list: D010655:Phenylenediamines; C034193:1,2-diaminobenzene; D001204:Ascorbate Oxidase; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid