Determination of oxprenolol by electrogenerated chemiluminescence

Abstract

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)₃²⁺] 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)₃²⁺ in 0.05 mol l^–1 phosphate buffer at pH 5.5, and a flow rate of 2 ml 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(30–12 000 ng ml^–1), with %s_r less than 5% for 5 replicates. The 3δ limit of detection was calculated as 35 nmol l^–1(11 ng ml^–1).