Determination of buprenorphine in pharmaceuticals and human urine by adsorptive stripping voltammetry in batch and flow systems

The adsorption of buprenorphine on carbon paste electrodes has been studied by cyclic (CV) and differential pulse voltammetry (DPV). By applying a sim ple electrode pretrearment good reproducibility of the current signal is ob tained (RSD = 0.85 %, n = 6 in CV and RSD = 0. 35 %, n = 6 in DPV for a 5.0 x 10(-7) M buprenorphine concentration in BR buffer pH 9.0). These methods permit a very sensitive (LD = 2.0 x 10(-8) M) and selective determination. They were applied to the quantitation of buprenorphine in human urine coin ing from subjects following buprenorphine treatment. The methodology was co upled to a flow system incorporating a thin-layer flow cell. A linear respo nse was obtained in the concentration range comprised between 1.0 x 10(-8) and 8.0 x 10(-7) M. The application to the determination of this molecule i n pharmaceuticals (vials and tablets) and human urine without any sample pr etreatment is studied.