PHOTOKINETIC DETERMINATION OF RIBOFLAVIN AND RIBOFLAVIN 5'-PHOSPHATE USING FLOW-INJECTION ANALYSIS AND CHEMILUMINESCENCE DETECTION

A flow injection procedure for the photochemical determination of ribo flavin and riboflavin 5'-phosphate has been developed. The method is b ased on the photo-reduction of both compounds by ethylenediaminetetraa cetic acid, the rate of which is a linear function of their concentrat ion at very low levels. The rate of these photochemical reactions was monitored by making use of the chemiluminescent hydrogen peroxide-lumi nol reaction and determining the hydrogen peroxide reduced by the 1,5- dihydro forms of these flavins, which are generated during the photoch emical process. Linear calibration graphs were obtained between 1 x 10 (-7) and 3 x 10(-6) mol l(-1). The method has been successfully applie d to the determination of B-2 vitamers in pharmaceutical preparations, foods and animal tissues.