共沉淀富集-冷原子吸收法测定饮水中痕量汞

DETERMINATION OF TRACE MERCURY IN POTABLE WATER SAMPLE ENRICHED BY PRECIPITATE WITH COLD_VAPOR ATOMIC ABSORPTION SPECTROMETRY

在中性或弱碱性条件下，向被测水样中加入适量Ｂｉ３＋和Ｎａ２Ｓ，使水样中的Ｈｇ２＋与Ｂｉ３＋一起形成硫化物（ＨｇＳ和Ｂｉ２Ｓ３）的共沉淀．将沉淀物用热稀硝酸溶解后，以冷原子吸收法测定其含量．探讨了对大体积水样沉淀富集时不须过滤（吸去上清液）的可行性，采用先加入明矾以加速硫化物的沉淀和凝结，而后吸去上清液的方法，从而使得该测定方法更简便和实用．

Hg 2+ can be precipitated with Bi 3+ in sulphide when Bi 3+ and sodium sulphide are added to water sample. After the sediment is dissolved by diluted nitric acid, the Hg 2+ in solution can be determined with cold vapor atomic absorption spectrometry. The precision and accurary of this method are comparatively high. These can be shown by repeated determination of the same water sample and by recovery test.