Rational design and preliminary analytical evaluation of two novel oxamide reagents for aqueous peroxyoxalate chemiluminescence

The synthesis, characterisation and preliminary analytical evaluation of a novel class of aqueous peroxyoxalate chemiluminescence reagents are described. The two oxamide reagents described incorporate the most desirable features associated with these types of compound, namely, good reactivity and no measurable background emission with analytically useful aqueous solubility. Sequential injection analysis was employed to evaluate the stability characteristics and analytical figures of merit for these compounds. The analytical performances of the new oxamides were assessed using the fluorophore rhodamine B, which realised non-linear calibration functions and detection limits in the range from 1 x 10-7 to 5 x 10-7 M. The non-sulfonated analogues of the two oxamides were also prepared and their performances compared favourably with that of bis (2,4,6-trichlorophenyl) oxalate. During the latter experiments, the calibrations more closely approached linearity with detection limits in the range from 9 x 10-8 to 5 x 10-7 M. Although the development of the novel class of oxamide reagent presented here has not yet realised its full potential, it is felt that this work represents a significant step forward in the development of truly aqueous peroxyoxalate chemiluminescence.