Extraction based on the flow-injection principle: Part 3. Fluorimetric Determination of Vitamin B1 (Thiamine) by the Thiochrome Method

The thiochrome method for determination of vitamin B₁ in pharmaceutical preparations has been adapted to a continuous flow system based on the flow-injection principle. The sample volume required for an analysis is about 150 /sml. For routine purposes a concentration range of 3 × 10^-4–6 × 10^-4 mg ml^-1 is used. Results obtained with the system agree well with results obtained manually. The consumption of organic phase is 2–3 ml/sample and the sampling rate is 30/h. A sampling rate of 70/h is easily attained if necessary. The relative standard deviation is about 1%.