Differential-pulse adsorptive stripping voltammetry of the diuretic torasemide at a hanging mercury drop electrode

Abstract

A method is described for the determination of torasemide, a loop diuretic, by differential-pulse adsorptive stripping voltammetry at a hanging mercury drop electrode. Accumulation of this diuretic was found to be optimized in Britton–Robinson buffer (pH 2.50) solution with the following conditions: accumulation potential, –900 mV; accumulation time, 30 s; and rest time, 10 s. Under these conditions, the current showed a linear dependence with concentration in the range 2.29 × 10–7–3.65 × 10–6 mol l–1. The reproducibility, in terms of relative standard deviation, for 10 determinations of 4.89 × 10–7 and 9.83 × 10–7 mol l–1 solutions was 1.80 and 0.90%, respectively; the detection limit was 80 ppb (2.29 × 10–7 mol l–1). The method was applied to urine samples spiked with torasemide, to obtain a recovery of 100.6 ± 3.4%.