微分电位溶出法测定尿中铅

In the determination of lead in urine by differential potentiometric stripping analysis (DPSA) urine samples are acidified with hydrochloric acid to a total concentration equal to 0.2 mol/L without prior digestion with mineral acids. The sample is pre-electrolyzed at -1.2V (Vs SCE) for 80 seconds by glassy-carbon electrode coated with mercury. The lead concentrations are evaluated by means of standard addition. Detection limit of the method is 2ppb. The linear relationship occurs in the range of 0-150ppb. The relative standard deviations are 1.6% and the recovery of lead in urine samples is 89.5-110.0%. Compared with dithizone method, this method shows no significant difference in the results obtained.     

酱油、醋中微量砷的催化示波极谱测定

作者采用示波极谱法测定酱油、醋中的微量砷。结果表明,在2mol/L H_2SO_4-0.2mol/L KI-5μg/ml Te体系中,砷于-0.73V(甘汞电极)有一个灵敏的催化波,线性范围在0～100ppb。酱油、醋用硝酸和高氯酸消化后测定砷,其检测限达1ppb,相对标准偏差分别为4.7％、8.8％,回收率分别为92％～102％、96％～110％。     

酱油,醋中微量砷的催化示波极谱测定

The determination of trace arsenic in soy and vinegar by oscillopolarography was investigated. A sensitive catalytic wave of arsenic appeared at -0.73V (vs. SCE) in 2mol/L H2SO4-0.2 mol/L KI-5 micrograms/ml Te systems. The linear relationship was 0-100ppb. The determination of arsenic in soy and vinegar was carried out after digestion with nitricperchloric acids. The detection limit was 1 ppb. The relative standard deviations were 4.7% and 8.8% respectively from the determinations of soy and vinegar. Recoveries were 92%-102% and 96%-110% respectively.     

微分电位溶出法测定尿中铅

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。