Voltammetric determination of parthenolide in spiked human plasma and urine

The voltammetric behaviour of parthenolide, a biologically active sesquiter pene lactone, was studied using direct current (DCt), alternating current a nd differential-pulse polarography (DPP), Parthenolide developed well-defin ed cathodic waves over the whole pH range in Britton-Robinson buffers, At p H 10 the diffusion current constant was 3.54 +/- 0.08 (+/- standard deviati on; n = 8), The current vs concentration plots were rectilinear over the ra nge 4-36 and 1-28 mug/mL in the DCt and DPP modes, respectively, with a min imum detectability of 0.06 mug/mL (about 1 x 10(-7) M) using the latter tec hnique. The waves were characterised as being diffusion controlled, althoug h adsorption phenomenon played a limited role in the electrode process, The described analytical method was applied to the determination of parthenoli de in spiked human urine and plasma; the percentage recoveries were 95.72 /- 0.22 and 94.0 +/- 0.13 (+/- standard deviation; n = 9), respectively. Co pyright (C) 2001 John Wiley & Sons, Ltd.