水样中痕量铜的富集和测定的研究

铜离子与1-(2-吡啶偶氮)-2-萘酚(PAN)反应,生成疏水性的络合物,在助溶剂乙醇的作用下,被萃取到三氯甲烷相中,用分光光度法测定三氯甲烷相中的Cu2+-PAN,建立了析相富集-分光光度法测定水样中痕量铜的分析方法。对影响络合反应和相分离的各种条件进行了优化。在选择的实验条件下,铜的质量浓度在0.50～15μg/mL范围内与吸光度呈线性关系,相关系数为0.999 57,方法的检出限为0.089μg/mL,对铜浓度为5.0μg/mL的样品溶液进行7次平行测定,相对标准偏差为1.67%。该方法用于水样中铜的测定,回收率在95.6%～101.5%之间。

Research on enrichment and determination of trace copper in water samples

After copper reacted with 1-(2-pyridylazo)-2-naphthol(PAN) to form a hydrophobic complex,the complex was extracted into trichloromethane phase with the existence of cosolvent ethanol,and then Cu2+-PAN in the phase was determined by spectrophotometry.A microsphere phase separation extraction-spectrophotometry for the determination of copper in water samples was developed.Various conditions influencing complexing reaction and phase separation were optimized.Under the selected experimental conditions,there was a linear relationship between absorbance and copper concentration in the range of 0.50~15 μg/mL with the correlation coefficient of 0.999 57.The detection limit was 0.089 μg/mL.The RSD was 1.67% for seven determination of 5.0 μg/mL copper.This method had been applied to determine copper in water samples with the recovery of 95.6%~101.5%.