电位溶出分析法同时测定罐头食品中痕量铅锡

利用不除氧电位溶出分析法成功地测定了溶出电位相近的Ｐｂ、Ｓｎ两元素。以０．０５ｍｏｌ／Ｌ草酸为介质，调节溶液ＰＨ＝１．０，以溶解氧做氧化剂，静止溶出，两元素均有分高清晰的平台出现。Ｐｂ、Ｓｎ的线性范围分别为：２．０×１０－９～２．０×１０－７ｍｏｌ／Ｌ和２．０×１０－８～２．０×１０－６ｍｏｌ／Ｌ。当富集时间为４ｍｉｎ时，Ｐｂ、Ｓｎ的检测限分别为５．０×１０－１０ｍｏｌ／Ｌ和５．０×１０－９ｍｏｌ／Ｌ。此法已成功地应用于测定罐头食品中的痕量Ｐｂ、Ｓｎ。

Simultaneous Potentiometric Stripping Analysis of Trace Lead and Tin in Tinned Food

Lead and tin, two elements with close stripping potential, are successfully determined by non-deoxygenated potentiometric stripping method. 0. 05 mol/L oxalic acid (pH= 1. 0) is used as the medium and the dissolved oxygen as the oxidant. After a static stripping procedure,clear separative platforms of the two elements can be found. The linear ranges of lead and tin are 2. 0×10-2. 0 ～10-7 mol/L and 2. 0 ×10-8～2.0×10-6 mol/L respectively. If the concentrating time is 4 min .the detectable concentrations of lead and tin are 5. 0×10-10 mol/L and 5. 0× 10- 9 mol/L. The method has successfully been applied to the determination of trace lead and tin in tinned food.