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-H2O2 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 × 10−5 to 5.2 × 10−4 M with kQ values of 1.15 × 104 and 1.28 × 104 M−1 for l-cysteine and l-methionine, respectively.