DETERMINATION OF OXPRENOLOL BY ELECTROGENERATED CHEMILUMINESCENCE

This work describes a novel method for the selective determination of oxprenolol, a beta-adrenergic antagonist, using flow injection analysis with electrogenerated chemiluminescence (ECL). The method is based on the ECL reaction of tris-(2,2'-bipyridine)ruthenium(II) [Ru(bpy)(3)(2+)] with the secondary amino group on oxprenolol. The factors affecting the determination were investigated and a calibration was obtained with 6.67 s pulses at +1.3 V, using 1.5 mmol l(-1) Ru(bpy)(3)(2+) in 0.05 mol l(-1) phosphate buffer at pH 5.5, and a flow rate of 2 mi min(-1). A linear calibration plot was obtained for signal (in mV) versus oxprenolol concentration (in mmol l(-1)) over the range 0.0001-0.04 mmol l(-1) (30-12000 ng ml(-1)), with % s(r) less than 5% for 5 replicates. The 3 delta limit of detection was calculated as 35 nmol l(-1) (11 ng ml(-1)).