示波极谱法同时测定尿中铅和镉

Simultaneous Determination of Lead and Cadmium in Urine by Oscilloscopic Polarography

研究示波极谱法同时测定尿中铅和镉的方法。运用正交试验选择底液的组成为碘化钾-抗坏血酸-浓盐酸-磷酸。用硝酸、高氯酸、盐酸混合酸消化尿样,消化液在酸性介质中,置极谱仪的三电极系统,样品溶液在滴汞电极上产生还原电流,分别于-480mV和-620mV处测量铅和镉的峰电流,对尿样中铅和镉进行测定,铅、镉的质量浓度在100μg.L-1以内与峰电流呈线性关系。铅、镉的相对标准偏差分别为6.91%,6.45%,检出限(3S/N)分别为2.0,1.0μg.L-1,回收率分别为88.4%～101.4%,83.1%～103.5%。

An oscilloscopic polarography method for simultaneous determination of Pb （ Ⅱ ） and CA （ Ⅱ） in urine was studied in this paper. The optimal composition of the supporting electrolytes was selected with orthogonal trial. Under conditions of the Optimal composition of supporting electrolytes of potassium iodide-ascorbic acidhydrochloric acid-phosphoric acid, Pb（ Ⅱ ） and Cd（ Ⅱ ） were determined and the linear relationship between peak current and concentration was observed in range of 100 μg · L^-1 for both Pb（Ⅱ） and CA（ Ⅱ）. RSD＇s of the determination were 6. 91% for Pb（Ⅱ ） and 6. 45% for CA（ Ⅱ ）. DL （3S/N） was 2.0μg · L^-1 for Pb（ Ⅱ） and 1.0 μg · L^-1 for CA（ Ⅱ ）. Recovery was in range of 88. 4%- 101. 4% for Pb（ Ⅱ ） and 83. 1% - 103. 5% for CA（Ⅱ）.