Post-chemiluminescence Phenomenon of NBS-Luminol Reactions and Their Applications to Flow Injection Analysis of Piroxicam

Abstract

A new post-chemiluminescence (PCL) reaction was observed when piroxicam was injected into the reaction mixture after the CL reaction of N-bromosuccinimide (NBS) and luminol. A possible reaction mechanism was proposed based on the studies of the CL kinetic characteristics, the CL spectra, fluorescence spectra and other experiments. A new flow injection CL method for the determination of piroxicam was established based on the PCL reaction. The relative standard deviation (RSD) for the determination of piroxicam was 1.2% (n = 11, c = 2.0 × 10^-6 g/ml). The CL intensity responded linearly to the concentration of piroxicam in the range 1.0 × 10^-7 - 1.0 × 10^-5 g/ml (r = 0.9991). The detection limit was 4.0 × 10^-8 g/ml. The method had been applied to the determination of piroxicam in tablets with satisfactory results.