title: Improved method for simultaneous determination of ascorbic acid and dehydroascorbic acid, isoascorbic acid and dehydroisoascorbic acid in food and biological samples.
abstract: The total vitamin C amount in different food and plasma samples was determined by a dual detection system, after HPLC separation, with direct detection of ascorbic acid and indirect fluorimetric detection of dehydroascorbic acid after a post-column O-phenyldiamine derivatisation. The two active forms of vitamin C and their D-isomers were separated within 10 min. The repeatability was determined by measurement of several fruits and vegetables and ranged from 0.3 to 1.9% (relative standard deviation) for vitamin C. The reproducibility, based on double determinations, ranged from 1.9 to 3.6% for vitamin C, depending on the matrix. The reproducibility, based on several determinations of reference materials, ranged from 2.4 to 3.7% for ascorbic acid and from 4.3 to 5.8% for dehydroascorbic acid, again depending on the matrix.
authors.affiliation: Danish Veterinary and Food Administration, Institute of Food Research and Nutrition, Ministry of Food, Agriculture and Fisheries, Søborg.
authors.forename: M A
authors.initials: MA
authors.lastname: Kall
authors.forename: C
authors.initials: C
authors.lastname: Andersen
mesh_terms: D001205:Ascorbic Acid / Q000031:analogs & derivatives / Q000032:analysis* / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005504:Food Analysis; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D014675:Vegetables / Q000737:chemistry*
chemical_list: D001205:Ascorbic Acid