Liquid chromatographic determination of vitamins B-1 and B-2 in foods. A collaborative study

A collaborative study was conducted to re-evaluate the chromatographic method proposed as the official French method in 1987 for the determination of vitamins B-1 and B-2 in foods. Twelve participants analysed nine samples containing various amounts of vitamin B-1 (from 1.1 to 4860 mu g g(-1)) and vitamin B-2 (from 2.1 to 871 mu g g(-1)). Reproducibility relative standard deviations (RSD(R)) were generally between 13 and 21% for vitamin B-1 determination, between 5 and 13% for vitamin B-2 determination, and did not appear to depend on the vitamin concentration. With all the foodstuffs studied, the recovery rate of the method was always superior to 89%, except with the chocolate powder, for which it reduced to approximately 50% for vitamin B-1 and 75% for vitamin B-2. In spite of this drawback, the chromatographic method proposed was confirmed as the official French method for vitamin B-1 and B-2 determination in foodstuffs for nutritional purposes. (C) 1996 Elsevier Science Ltd.