微分电位溶出法同时测定食品中铅、锡

Simultaneous Determination of Lead and Tin in Food by Differential Potentiometric Stripping Analysis

利用微分电位溶出分析法，以0．09mol／L草酸、7．5×10^-5mol／L中性红为底液，同时测定了4种样品中的铅、锡含量，二元素峰电位分别为-0．52V和一0．62V（VSSCE），铅、锡的线性范围分别为2．0～100．0ng／mL、5．0～250．0ng／mL．当富集时间为60s时，铅、锡的检出限分别为2ng／mL和5ng／mL．将此法应用于测定食品中痕量铅和锡，结果满意．

A method of simultaneous determination of lead and tin in food by differential potentiometric stripping analysis is reported. The base solution contains 0.09 mol/L oxalic acid and 7.5 ×10^-5 mol/L neutral red. Experimental results show that the method has a good linearity of peak heights vs concentrations in the range of 2.0-100.0 ng/mL and 5.0-250.0 ng/mL and the peak potentials are at -0.52 and -0.62 V（vs SCE） for Pb^2＋ and an^4＋ respectively. The method has been used to determine these elements in some foods with satisfactory results.