无火焰原子吸收法测定饮用水中铅和镉的条件探讨

Graphite oven-atomic absorption spectrometery determination of lead and cadmium in drinking water

目的探讨石墨炉-原子吸收光谱法检测生活饮用水中的铅、镉元素简便准确的测定条件。方法探究了普析通用TAS990原子吸收分光光度计测定饮用水中铅、镉含量的最佳升温程序,采用标准加入法不加基体改进剂不扣背景分析测定生活饮用水中铅、镉,分别以未检出、检出铅和镉水样为稀释液的标准加入法曲线K值与标准曲线的K值进行比较。结果在优化条件下,铅的两种稀释液标准加入法曲线K值与标准曲线的K值比值分别为0.96和1,镉的两个比值为0.97和1,铅标准样品GSB07-1183-2000(201231)(35.3±1.9)μg/L,测定结果 37.1μg/L,镉标准样品GSB07-1185-2000(201427)(45.3±2.7)μg/L,测定结果 42.9μg/L,2个元素测定精密度在4.32%～9.89%。结论K值相同即接近或等于1,石墨炉-原子吸收光谱法测定生活饮用水中铅和镉基质干扰不会影响检测结果,可以简化操作条件不扣除背景,铅和镉的标准样品在保证范围内,方法简便、准确。

Objective The determination of lead and cadmium in drinking water by graphite furnace-atomic absorption spectrometry was discussed.Methods Explores the general analysis of TAS990 atomic absorption spectrophotometer determination of lead,cadmium content in drinking water,the best temperature program,using the standard addition method and matrix modifier and buckle background analysis for determination of lead,cadmium in drinking water was optimized,compared with not checked out,two different preliminary treatmentsof water sample's standard addition method's K value were compared. Results Under optimized conditions,the two diluent standard addition method of lead curveK value and the standard curve of the K value were 0.96,1,and the two ratio is 0.97,1,cadmium lead standard sample GSB07-1183-2000 (201231)to 35.3+1.9 μg/L,the determination results of 37.1μg/L,cadmium standard sample GSB07-1185-2000 (201427)to 45.3+2.7 μg/L,the determination results of 42.9 μg/L,precision was 4.32%~9.89%.Conclusion K value is close to or equal to 1,same-graphite furnace atomic absorption spectrometry determination of lead and cadmiumin drinking water matrix interference,will not affect the test result of lead and cadmiumstandard sample within the scope of the guarantee,the method is simple and accurate.