微分电位溶出法测定尿中铅

DETERMINATION OF LEAD IN URINE BY DIFFERENTIAL POTENTIOMETRIC STRIPPING ANALYSIS

作者研究了用微分电位溶出法测定尿中铅。尿样用盐酸酸化至0.2mol/L,直接用预镀汞膜的玻碳工作电极在-1.2V(对SCE)富集80秒,用标准加入法定量。结果:铅的线性范围在0～150ppb,检出限达2ppb,尿样中铅的回收率达89.5～110.0％,相对标准偏差为1.6％。本法灵敏、快速、准确、简便,而且成本低廉,样本不需消化处理,不使用有机溶剂等有毒物质;与双硫腙法比较,其结果无显著性差异。

In the determination of lead in urine bydifferential potentiometric stripping analysis(DPSA) urine samples are acidified withhydrochloric acid to a total concentrationequal to 0.2 mol/L without prior digestionwith mineral acids.The sample is pre-elec-trolyzed at-1.2V (Vs SCE) for 80 secondsby glassy-carbon electrode coated with mer-cury. The lead concentrations are evaluatedby means of standard addition. Detectionlimit of the method is 2ppb. The linearrelationship occurs in the range of 0-150ppb.The relative standard deviations are 1.6%and the recovery of lead in urine samplesis 89.5-110.0%. Compared with dithizonemethod, this methed shows no significantdifference in the results obtained.