DETERMINATION OF VITAMIN C IN SERUM BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY / 营养学报

ABSTRACT

Objective: To assay the content and stability of vitamin C(VC) in serum by a simple, specific method. Methods: Serum samples were extracted by metaphosphoric acid, and analyzed on a column C 18 of HPLC with DAD detector at 234 nm. Mobile phase was 100 mmol/L KH 2PO 4, pH3.00. The flow rate was 1 ml/min. Results: Under this condition, the retention time of VC was 5.76 min. The within run and between run reproducibilities tests were 0.42% and 2.11% respectively, and the recovery rate ranged from 82% to 88.5%. Stored at -70 ℃ and compared to that of its metaphosphoric acid extract, serum VC content was stable only for two days, and then decreased rapidly, whereas it did not decrease in metaphosphoric acid extract until the fifth day. Conclusion: A simple, sensitive and reliable method of HPLC with DAD detector is established for measuring VC in either serum or fruit, such as orange juice. VC should be determined immediately or should be extracted with metaphosphoric acid as soon as possible, then the extracts are kept at -70 ℃, and analysed within 5 d.