单扫描示波极谱法测定皮蛋中微量铅的方法研究

Method to Detect Lead in Preserved Egg by Single Sweep Polarography

在0.01g/mL碘化钾,0.016g/mL酒石酸钾钠,0.001g/mL抗坏血酸,0.24mol/L盐酸底液中,采用单扫描示波极谱法获得铅和碘络合物吸附波,用于皮蛋中微量铅的测量。文中讨论了碘化钾、酒石酸钾钠、抗坏血酸、盐酸的加入量及静止时间对反应的影响从而确定了适宜的实验条件。实验表明,铅在此底液中峰电位在-520mV,峰电流与铅离子的浓度在0.2～1.0μg/mL范围内呈良好的线性关系,线性回归方程为:Iy=2 492.2Cx+332.1,相关系数r2=0.999 4。回收率为98.4%～103.9%。此方法测定皮蛋中微量铅,仪器简单,操作快速、简便,准确度高,测定结果令人满意。

This article studies the method to detect lead in preserved egg by single sweep polarography. In 0.01g/mL potassium, 0.016g/mL tartaric acid potassium sodium, 0.001g/mL ascorbic acid and 0.24mol/L hydrochloric acid bottom fluid, single sweep polarographic method is used to get the wave of lead and potassium complex adsorption to trace lead measurement. The paper dis- cusses the dosage of potassium, tartaric acid potassium sodium, ascorbic acid and hydrochloric acid and the influence of the static time on the reaction to determine the appropriate experiment conditions. Experiments show that lead shows good linear relationship in this base solution in - 520 mV,peak current and lead ion concentrations in the range 0.2-1.0 μg/mL. The equation of linear regression is Iy=2 492.2Cx ＋332.1 and the related coefficient is r2 =0. 999 4 and the recovery rate is 98.4%-103.9%. With this method to determine trace amounts of lead in preserved egg, the instrument is simple, the operation is fast and convenient and the accuracy is high and the measurement results are satisfactory.