匹鲁卡品的电分析化学研究

本文用微分脉冲极谱法和循环伏安法研究了匹鲁卡品的电化学行为,选择了Zn(Ⅱ)—匹鲁卡品法测定的最佳条件,建立了测定方法,俭出限可达8.0×10^-7mol/L;同时还制备了匹鲁卡品—PVC膜离子选择性电极,直接应用于匹鲁卡品注射液的测定,毋需分离,简便快速,结果良好。

ELECTROANALYTICAL CHEMISTRY STUDY OF PILOCARPINE

The electrochemical behaviour of pilocarpine was investigated by differential pulse polarography and cyclic voltammetry. The optimum conditions for the determination of pilocarpine were as follows: The electrolyte was 0.4 mol/L HAc-NaAc(pH 4.0) buffer solution, Zn (II) 1.0 x 10(-3) mol/L; initial potential -0.80 V (vs Ag-AgCl), final potential -1.30 V (vs Ag-AgCl), and voltage sweep rate 5 mV/s. A fair reproducibility in the above procedure and a good relationship between peak current and pilocarpine concentration (4.0 x 10(-6)-4.0 x 10(-5) mol/L) were achieved. The detection limit was 8.0 x 10(-7) mol/L. This paper also reports that the application of cyclic voltammetry to study electrode process behavior has been established. The PVC membrane ion-selective electrode for pilocarpine also was studied. It is based on the use of tetraphenylborate pilocarpine ion pair complex as the active material. The PVC membrane electrode showed Nernstian response over the pilocarpine concentration range from 1.0 x 10(-2) to 3.0 x 10(-5) mol/L, with a slope of 36 mV/decade, the detection limit being 3.0 x 10(-6) mol/L. The electrode gave fast response and good reproducibility. This method provides a rapid and simple way to the determination of pilocarpine in pharmaceutical preparations.