镁-8-羟基喹啉快速共沉淀分离富集内标火焰原子吸收光谱法测定水样中铜和铅

Application of internal standard to rapid coprecipitation technique with Mg-8-oxyquinoline for flame atomic absorption spectrometric determination of copper and lead in water samples

研究了以镁-8-羟基喹啉共沉淀体系，锰（Ⅱ）为内标，快速共沉淀分离富集水样中铜和铅，火焰原子吸收光谱（FAAS）测定的方法。共沉淀受体系酸度、载体镁、沉淀剂8-羟基喹啉和内标锰的用量及陈化时间的影响。结果表明：锰（Ⅱ）作为内标元素可以满足共沉淀的要求；在最佳实验条件下，Cu，Pb和Mn都均匀分布在整个沉淀中，且质量保持一定比例，无需收集全部沉淀；标准曲线与标准加入曲线的斜率无显著差异，基本消除了基体干扰。方法的检出限为铜6．28×10^-3 μg／mL，铅2．26×10^-2μg／mL用于水样分析加标回收率为95．4％～104．2％，相对标准偏差为2．4％～4．0％。

A method was proposed for the determination of copper and lead in water sample by flame atomic absorption spectrometry after preconcentration using rapid coprecipitation technique with 8-oxyquinoline Mg（Ⅱ） coprecipitation system and manganese（Ⅱ） as internal standard. The coprecipitation was affected by pH of system, the content of magnesium, manganese（Ⅱ） and 8-oxyquinoline in solution. The results show that manganese as internal standard satisfied the requirements. It need not to collect all the coprecipitation, so it spared the time. The effect of matrix can be overcome by the method of the calibration curve method, and the standard addition method, and the results are satisfied. The detection limit is 6.28 × 10-3μg/mL for copper and 2.26 × 10^-2μg/mL for lead of the method. The standard addition recovery is between 95.4%-104.2%, and RSD of 2.4% -4.0%.