Voltammetric determination of parthenolide in spiked human plasma and urine

The voltammetric behaviour of parthenolide, a biologically active sesquiterpene lactone, was studied using direct current (DCt), alternating current and differential-pulse polarography (DPP). Parthenolide developed well-defined cathodic waves over the whole pH range in Britton–Robinson buffers. At pH 10 the diffusion current constant was 3.54 ± 0.08 (± standard deviation; n = 8). The current vs concentration plots were rectilinear over the range 4–36 and 1–28 µg/mL in the DCt and DPP modes, respectively, with a minimum detectability of 0.06 µg/mL (about 1 × 10−7 M) using the latter technique. The waves were characterised as being diffusion controlled, although adsorption phenomenon played a limited role in the electrode process. The described analytical method was applied to the determination of parthenolide in spiked human urine and plasma; the percentage recoveries were 95.72 ± 0.22 and 94.0 ± 0.13 (± standard deviation; n = 9), respectively. Copyright © 2001 John Wiley & Sons, Ltd.