Journal of chromatography. B, Biomedical sciences and applications

Improved method for simultaneous determination of ascorbic acid and dehydroascorbic acid, isoascorbic acid and dehydroisoascorbic acid in food and biological samples.

PMID 10437677


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.