极谱催化波法测定食品中痕量砷

Measurement of Arsenic in Food with Polarographic Catalytic Wave Method

本文应用As—Fe—NH_4I—H_2SO_4体系极谱催化方法测定食品中痕量砷,确定了适合的底液条件和样品消化方法.底液为 5.0μg/mol Te—0.2mol/L NH_4I—3.6mol/L H_2SO_4样品采用H_2SO_4、热HNO_3混酸加热消化,扫描电位在峰电位前0.22V,参考峰电位—0.76V,峰—峰间距为30mV.回收率为91％～105％,变异系数为3.6％,线性范围0.01～0.5mg/L.

An analytical method of the micre arsenic in food is described in this paper by means of poparographic catalytic wave method in the As-Te -NH4I-H2SO4 system. And the proper base liquid condition and the way of the sample disappearance are determined. The base liquid . 5.0g/mol Te -0. 2mol/L NH4I-3.6mol/L H2SO4 system. The way of the disappearance:H2SO4-HNO3 system. The sanning potential:0. 22V,before the peak potential. The reference potential:-0.76V. The peak-peak distance:30mV. The retrieve rate 91~105%.The deviation rate 3.6%.The range of linearity :0. 01~0.5mg/L.