Investigation on Voltammetric Behavior of Camptothecin and Its Analytical Application

The voltammetric behavior of camptothecin (CPT) in Britton-Robinson (B-R) buffer solutions (pH 2.09–9.07) was studied by the means of linear sweep voltammetry (LSV), cyclic voltammetry (CV) and normal pulse voltammetry (NPV) at a hanging mercury drop electrode. In different pH range of B-R buffer solutions, CPT could cause three reduction waves. In B-R buffer solutions (pH 2.09–5.46), wave P₁ yielded by CPT was a two-electron wave. Between pH 6.01 and 9.07, CPT could yield two reduction waves P₂ and P₃. In addition, the pure CPT obtained from camptotheca acumina grown only in China was determined by NPV, and a linear response was observed in the range of 2.0×10⁻³–4.0×10⁻² mmol·L⁻¹ with a 0.9991 correlation coefficient and a 8.0×10⁻⁴ mmol·L⁻¹ detection limit for CPT.