Peroxyoxalate chemiluminescence of 1,4-dihydroxy-3-methyl-thioxanthone and quenching effect of β-cyclodextrin

Abstract

The chemiluminescence generated from the reaction of bis(2,4,6-trichlorophenyl) oxalate (TCPO), hydrogen peroxide and 1,4-dihydroxy-3-methyl-thioxanthone (DMT) was investigated. Effects of reacting components, solvent and concentrations of TCPO, sodium salicylate, hydrogen peroxide and DMT were studied and their optimal values were determined. In addition, the influences of b-Cyclodextrin (b-CD) on the peroxyoxalate chemiluminescence (PO-CL) system of DMT were examined at optimized condition. The results showed that the presence of b-CD causes both enhancing and quenching effects on PO-CL system of DMT based upon its concentration. The Stern-Volmer quenching constant (K q ) was evaluated as 2.32 9 10 4 M -1 (R 2 = 0.991) by creating a linear regression plot on experimentally obtained data. This study resulted in satisfactorily determination of b-CD in the range 5.0 9 10 -6 to 1.0 9 10 -4 M.