冷原子-无色散原子荧光光谱法测定奶粉中汞的有关问题的探讨

Study on Some Problems of Mercury in Milk Powder by Cold Atomic-Unchromatic Dispersion Atomic Fluorescence Spectrophotometry

本文第一次提出汞样品经硝酸消化后，汞（Hg）与氮氧化物（NxOy）形成络合物，在经典的加氯化亚锡（SnCl2）还原时，生成Hg与NxOy并能同时追出，确定了Hg与NxOy存在配位关系，对汞的测定在数学计量上增加到1．5倍，结果表明，应用五氧化二钒消化奶粉样品能如实反映这一关系，并精确地得出其汞含量。在联合国环境规划署和粮食农业组织及世界卫生组织食品污染联合监测计划的第八届铅、镉、汞的分析质量保证中，应用本法测得结果与真实值一致。本文对方法的研究，不但对汞的测定提高了准确度和灵敏度，而且为重新认识其反应机理以新的启迪。

A theory about reduction reaction of mercury by cold atomic-unchromatic disper sion atomic fluorescence spectrophotometry is proposed. After a sample containing mercury has been digested with nitric acid. the mercury reacts with a nitrogen oxide (NxOy ) come from products of digestion to form a Hg (NxOy ), complex compound. Added tin protochloride liquor (SnCl2 ). the complex compound is decomposed, and Hg2+ is reducted to Hg0 and NxOy is released. both are carried out liquor to detector by N2, so the sensitivity is raised 1. 5 times. The application of this method has been confirmed by Joint UNEP/FAO/WHO food contamination monitoring programme for analytical quality assurance-milk powder test mate rial for lead, cadmium and mercury analysis: study Ⅷ(1994).