title: Measurement of ascorbic acid in human plasma and urine by high-performance liquid chromatography. Results in healthy subjects and patients with idiopathic calcium urolithiasis.
abstract: A simple, reliable high-performance liquid chromatographic method was developed to measure ascorbic acid (ASC), with ultraviolet detection (250 nm), in human plasma and urine. Immediately following blood withdrawal, the heparinized plasma samples were deproteinized with 10% m-phosphoric acid, while the freshly voided urine samples were diluted with m-phosphoric acid. ASC was separated on a reversed-phase column by elution with 0.1 M KH2PO4 adjusted to pH 2.35. In urine, after reduction of dehydroascorbic acid to ASC, total ASC was measured using the same mobile phase. The method was sensitive down to 0.1 and 0.4 mg ASC per litre of urine and plasma, respectively. In patients with idiopathic calcium urolithiasis, both plasma and urinary ASC were within the range observed in age-matched controls.
authors.affiliation: Department of Surgery, University Hospital, Erlangen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Manoharan
authors.forename: P O
authors.initials: PO
authors.lastname: Schwille
mesh_terms: D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000032:analysis* / Q000097:blood / Q000652:urine; D002118:Calcium; D002851:Chromatography, High Pressure Liquid / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010756:Phosphoric Acids; D011786:Quality Control; D012016:Reference Values; D012680:Sensitivity and Specificity; D014545:Urinary Calculi / Q000097:blood / Q000378:metabolism* / Q000652:urine
chemical_list: D010756:Phosphoric Acids; C030242:phosphoric acid; D001205:Ascorbic Acid; D002118:Calcium