化学修饰电极预富集—石墨炉原子吸收法测定土壤中可溶性铅

研究了用Ｎａｆｉｏｎ化学修饰电极预富集－石墨炉原子吸收法测定土壤中可溶性铅的方法。土壤经０．１ｍｏｌ／Ｌ ＨＣｌ处理，以Ｎａｆｉｏｎ修饰的钨丝电极富集可溶性痕量铅后，放入石墨杯中进行原子吸收法测定。实验结果，在ｐＨ３．５的ＨＣｌ介质中，测定的线性范围为０～４．５μｇ／Ｌ，检测限为０．０４μｇ／Ｌ；对浓度为２μｇ／Ｌ的铅标准溶液平行测定１０次，相对标准偏差为２．６％；１０多种离子不干扰测定，样品回收

Determination of Soluble Lead in Polluted Soil by GFAAS with Electro-Chemical Preconcen- tration of Chemically Modified Electrode

This paper described a method for determining soluble load in soil by using graphite furnace AAS with electrochemical Preconcentration of Nation chemically modified electrode. A coiled tungsten wire was modified with a thin film of Nafion. Trace amount of soluble lead was precon-centrated by the electrode when the soil sample was treated by 0.1mol/1 HC1, then put into a graphite cup for ASS measurement. In a solution of HC1 at pH3.5, the linear range for che determination was 0-4.5ppb. The relative standard deviation for ten parallel determinations of a solution containing 2 ppb lead was 2.6%. The detection limit was 0.04ppb. More than ten foreign ions did not interfere significantly. The recovery rate was 91-108%.