Effects of glutathione, l-cysteine, and l-methionine on the kinetics and mechanism of the peroxyoxalate–rubrene–H2O2 chemiluminescence system

Abstract

The quenching effect of glutathione, L-cysteine, and L-methionine on the strong chemiluminescence (CL) intensity of bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H 2 O 2 in the presence of rubrene (5,6,11,12-tetraphenylnaphthacene) as a fluorescer was investigated. Kinetic parameters for the peroxyoxalate chemiluminescence (PO-CL) including the intensity at maximum CL, time at maximum intensity, total light yield, theoretical maximum level of intensity and pseudo-first order rate constants for the rise and fall of the CL burst (k r and k f ) were also calculated using the pooled intermediate model by a computerized non-linear leastsquares curve fitting program (KINFIT). These systems resulted in Stern-Volmer plots in the quencher concentration range of 2.5 9 10 -5 to 2.25 9 10 -4 M, with k Q values of 2.5 9 10 4 , 2.1 9 10 4 and 1.1 9 10 4 M -1 , for glutathione, L-cysteine, and L-metionine, in order.