Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 39 3 2001 09 15 159 163 Oveisi MR Sadeghi N 2015 09 28 The total vitamin C content in human plasma is widely accepted as an indicator of the tissue status of vitamin C. A liquid chromatography method with ultraviolet detector (264 nm) for measuring ascorbic acid in human plasma was developed. A C18 reversed-phase column and cetrimide as an ion-pairing agent was employed. Ascorbic acid (AA) was measured after reducing L-dehydroascorbic acid to L-ascorbic acid with dithiothreitol. The stability of the ascorbic acid in plasma, metaphosphoric acid and trichloroacetic acid was also evaluated. The analytical parameters, including linearity (1-60 µg/ml), accuracy (98.98%), repeatability (2.8%) and reproducibility (7.2%), showed that the method is reliable for measuring the total vitamin C content in plasma. https://acta.tums.ac.ir/index.php/acta/article/view/2427 https://acta.tums.ac.ir/index.php/acta/article/download/2427/2416