铋膜电极微分脉冲溶出伏安法测定食用明胶中的铅

Determination of trace lead in gelatin by differential pulse stripping voltammetry

通过铋膜修饰的玻碳电极,建立了明胶中铅的差分脉冲溶出伏安分析法.结果表明,在pH=4.0的HAc-NaAc缓冲介质中,-1.0 V富集300 s后,溶出峰电流与Pb^2＋浓度在50～1 000 μg/L范围内呈线性关系,相关系数r=0.995 6,在实际样品测量中,回收率在97.75%～104.79%,相对标准偏差为2.20%.

Use bismuth-film-modified glassy carbon electrodes, a novel differential pulse stripping voltammetry was developed for the determination of the content of the lead in the gelatin. The result showed that the calibration plot was linear in the range of 50 - 1 000 μg/L with regression coefficient of 0. 995 6 under the optimal analytical conditions i e. cathodic depositing 300 s at - 1.0 V in HAc-NaAc buffer solution （ pH = 4.0）. The recovery of Pb^2＋ is between 97.75 % and 104.79 % for purified in market, and the relative standard deviation is 2.20%.