共沉淀预富集-火焰原子吸收法测定水中的铅和镉

在弱氧化剂存在下，二乙基二硫代氨基甲酸钠作为共沉淀剂预富集水中的铅和镉，加入饱和明矾溶液以加速沉淀物的生成和凝聚，虹吸除去上层清液（无需过滤），用硝酸溶解沉淀，火焰原子吸收测定铅和镉的含量。方法简便、实用，具有较高的准确度和精密度，适用于大体积水样预处理及重金属元素的测定。

Co-Precipitative Pre-Concentration with Sodium Diethyldithiocarbamate and Flame Atomic Absorption Spectrometric Determination of Pb and Cd in Water

Sodium diethyldithiocarbamate in presence of a weak oxidizing agent was used as a co precipitative agent for the pre concentration of Pb and Cd. The addition of the saturated alum solution is proposed to accelerate to the production and condensation of the precipitate. The clear supernatant solution was then siphoned off ( no filter ). The precipitate is dissolved with HNO 3 ,and the concentrated elements Pb and Cd were determined by flame atomic absorption spectrometry. The method is simple and practical with good accurate and precision.So that it was applied to heavy metal elements analysis in the big volume aqueous.