Determination of hydroxyproline in meat products by flow injection analysis

SummaryA modification of the German standard method for the determination of hydroxyproline (DIN 10144) is described. By applying a thermostatted reaction coil the relatively slow developing colour reaction between pyrrols and 4-dimethylaminobenzaldehyde could be adapted to FIA-conditions. The presented FIA-method allows for an injection frequency of 80/h and a sample throughput, on routine basis, of about 40/h. The reproducibility of multiple injections in the range 20–200 mg hydroxyproline/l hydrolysate is 1.5% r.s.d. Sulfuric and hydrochloric acid have been used for hydrolysis.