荧光光度法选择性测定水样中痕量镉的研究

本文研究了镉 (Ⅱ ) 8 羟基喹啉 5 磺酸 溴代十六烷基三甲胺体系测定痕量镉的荧光分析方法。Cd(Ⅱ )与 8 羟基喹啉 5 磺酸 (HQS)在强碱性条件下能选择性地形成稳定的配合物 ,发射较强的荧光 ,激发波长和发射波长分别位于 394nm和 5 2 0nm。在溴代十六烷基三甲胺 (CTMAB)表面活性剂存在时 ,络合物的荧光强度显著地增强。在碱性条件下 ,CTMAB浓度为 3× 1 0 3mol/L时 ,镉 (Ⅱ )的浓度在 4 3× 1 0 9～ 6 0× 1 0 6 mol/L范围内线性关系良好 ,检出限为 4 3nmol/L。应用本方法测定生活及环境水样后 ,共加标回收率为1 1 7 1 %～ 1 2 1 8%。本方法操作简便、选择性好、准确度高 ,可直接应用于水样品中镉含量的测定 ,结果令人满意

Selective determination of trace cadmium in water samples by fluorescence spectrometry

This paper studies a selective analytical method for the determination of trace cadmium by the fluoresxence characteristic of cadmium chelates,The excitation and emission wavelengths of the fluorescence of the complex were 394nm and 520nm respectively.Under the heavy base condition,Cd(Ⅱ) could form stable complex selectively with 8 hydroxyquinoline 5 sulphonic acid(HQS),and other metal ions such as Zn 2+ ,Cu 2+ ,Mg 2+ could not form the stable complex.The fluorescence was greatly increased in the presence of CTMAB.The results obtained under optimum conditions show that the linear range is 4 3×10 9 ～6 0×10 6 mol/L and the detection limit 4 3 nmol/L.The recoveries are between 117 1% and 121 8% for the determination of tap water and cannel water samples.The method is simple,selective and reliable.The method was applied to the analysis of tap water and environmental water samples with satisfactory.