双硫腙分光光度法测定离子液体中Zn^(2+)含量

Spectrophotometric Determination of Zn^(2+) in Ionic Liquid with Dithizone

利用双硫腙与锌离子可生成稳定红色络合物的性质,建立以甲醇为溶剂,采用可见分光光度法,定量测定室温离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bm im]BF4)中锌离子含量的方法。在波长507 nm下,锌离子的质量浓度在40.5~405μg.L-1之间与吸光度成较好的线性关系,符合朗伯-比尔定律,线性回归方程:A=0.000 83ρ+0.004 41,r=0.998 6,摩尔吸光系数:5.43×104L.mol-1.cm-1。该方法重复性良好,相对标准偏差为7.5%(n=5),平均回收率为102%。

A method for the determination of zinc in ionic liquid （ 1 -butyl-3-methylimidazolium tetrafluoroborate） by speetrophotometry with dithizone was developed. Zn^2＋ can react with dithizone to form a stable red chelate complex in methanol exhibiting a maximum absorbance at λ507nm. The linear range of the calibration curve is 40. 5 -405μg/L with a correlation coefficient of 0. 998 6 and a molar absorptivity of 5.43 × 10^4 L· mol^-1· cm^ -1. The relative standard deviation is 7.5% （ n = 5 ） and the average recovery is 102%.