甲基汞的分光光度测定方法研究

Determination of Methylmercury by Spectrophotometry

建立了测定甲基汞的分光光度法 .该方法是基于甲基汞与硫代米氏酮形成络合物 ,最大吸收波长为 5 6 4nm .可在水相测定 ,也可用正丁醇萃取后测定 .线性围 :当浓度为 1× 1 0 -7mol/L～ 1× 1 0 -6mol/L时 ,相关系数为 0 9938;当浓度为 1× 1 0 -6mol/L～ 2× 1 0 -5 mol/L时 ,相关系数为 0 9997.ε为 5 0 5× 1 0 4L·mol-1·cm-1,检出限为 1 0ng/ml.该方法已用于鱼样中甲基汞的测定 ,回收率为 91 %～ 1 0 3% .相对标准偏差为 7.2 % .

The spectrophotometric method for the determination of methylmercury based on formation of the complex with thio Michler’s ketone in n butanol was established.The pH was adjusted to 4.7 with acetate buffer.The complex was formed immediately,and stable up to 100 min.The maximum absorption wavelength was at 564nm.The Lambert Beer law was obeyed for methylmercury between 1×10 -7 mol/L～1×10 -6 mol/L and 1×1 -6 mol/L～2×10 -5 mol/L with correlation coefficients of 0.9938 and 0.9997, respectively.ε was 5.05×10 4L·mol -7 ·cm -1 and the detection limit was 10ng/ml.The method has been applied to analysis of methylmercury in fish.The recovery was from 91% to 103% and the relative standard deviation was 7.2%.