电热原子吸收光谱法测定水中总钼

建立电热原子吸收法测定水中总钼的含量。样品采用硝酸–过氧化氢消解,热解涂层石墨管减小记忆效应,塞曼背景校正消除背景噪声。检测了27种共存离子的干扰影响。经6家实验室对标准物质和实际样品检测验证,方法检出限为0.6μg/L,能够满足微量检测要求。钼测定结果相对误差最大值为–6.2%,实验室内相对标准偏差为4.5%~7.6%(n=6),实验室间相对标准偏差为4.3%~5.7%(n=6),加标回收率为91.8%~104.0%。该方法精密度和准确度满足我国地下水和废水监测技术规范的质控要求。

Determination of Total Molybdenum in Water by Electro-Thermal Atomic Absorption Spectrometry

The method for determining total amount of molybdenum in aqueous samples by acid digestion-Zeeman background correction-electro-thermal atomic absorption spectrometry was established.HNO3-H2O2was used for digesting sample. Pyrolytically coated tubes was used to reduce the formation of carbides, and Zeeman background correction was used to correct the background noise. The interferences of 27 kinds of coexisting ions were detected. The detection limit of the method was 0.6μg/L, which could meet the requirements of trace detection. The maximum relative error of molybdenum detection was -6.2%. The RSD in laboratory was 4.5%-7.6%(n=6), the RSD inter laboratory was 4.3%-5.7%(n=6), and the recovery ranged from 91.8% to 104.0%. This method could meet the requirements of quality control in groundwater and waste water monitoring.