[Determination of vitamins B1 and B2 in selected vegetable-fruit products].

A simple method was described to determine vitamins B1 and B2 in fruit and vegetable-fruit juices. Vitamins were extracted with perchloric acid and for their determination an ion pairing RP-HPLC technique with UV detection by 254 nm was applied. The average recovery for vitamin B1 was 85-104% and 94-105% for vitamin B2. The statistically estimated limits of identification and detection were respectively, for both vitamins: for B1: 0.008 and 0.0024, and for B2 0.0002 and 0.0007 mg/ml of product.