A sub-picomole level topotecan hydrochloride determination method was first proposed using sodium dodecyl sulfate (SDS) as a sensitized reagent at a novel disposable electrode (an improved wax-impregnated graphite electrode).The effects of different kinds of surfactants on the electrochemical response to topotecan hydrochloride were examined.The results indicate the electrochemical signal was apparently improved by SDS.At optimal conditions,the oxidative peak current increased linearly with the logarithm of concentrations for topotecan hydrochloride in the ranges of 2.0 × 10-12 to 1.0 × 10-11 mol/L and 8.0 × 10-11 to 8.0 × 10-10 mol/L with a detection limit of 6.4 × 10-13 mol/L.The proposed method could be applied in determining topotecan hydrochloride in urine.
