CHEMILUMINESCENCE DETECTION OF PORPHYRINS WITH THE PEROXYOXALATE REACTION BY FLOW-INJECTION ANALYSIS

The chemiluminescence (CL) reaction of bis(2,4-dinitrophenyl) and bis( 2,4,6-trichlorophenyl) oxalate with hydrogen peroxide was employed for the study of CL-emission characteristics from porphyrins. The effects of experimental factors such as pH, solvents, flow rate, and reagent concentrations on CL kinetics and intensity were investigated. Based o n these studies, a new method involving the coupling of CL with flow i njection analysis (FLA) was developed for the rapid screening of porph yrin(s) present in a real simple matrix, with good sensitivity, select ivity and precision. Under optimized conditions, the detection limit f or urinary coproporphyrin was about 0.1 mu l(-1) (S/N=3) and the avera ge precision was about 1.5% (rsd). Perhaps, most importantly, signific ant enhancement in the selectivity was demonstrated for the CL detecti on of coproporphyrin against common urinary metabolites, such as ribof lavin and bilirubin, when compared with fluoresence detection.