A study of quenching effect of sulfur-containing amino acids L-cysteine and L-methionine on peroxyoxalate chemiluminescence of 7-amino-4-trifluoromethylcumarin.

The quenching effect of L-cysteine and L-methionine on strong chemiluminescence of bis-(2,4,6-trichlorophenyl)oxalate-H(2)O(2) system in the presence of 7-amino-4-trifluoromethylcumarin was studied. The chemiluminescence parameters were evaluated from computer fitting of the resulting intensity-time plots. Both systems resulted in Stern-Volmer plots in the quencher concentration range of 6.5 x 10(-5) to 5.2 x 10(-4)M with k(Q) values of 1.15 x 10(4) and 1.28 x 10(4)M(-1) for L-cysteine and L-methionine, respectively.