锌试剂-甲醇分光光度法测定离子液体中的锌含量

Spectrophotometric Determination of Zinc in Ionic Liquids with Zincon-methanol

在甲醇溶剂中，锌试剂与锌离子生成稳定的蓝色络合物，采用可见分光光度法能够测定室温离子液体1-丁基-3-甲基眯唑四氟硼酸盐（[bmim]BF4）中锌离子的含量．在波长639nm处，锌离子的浓度在0．324～0．891mg·L^-1之间与吸光度成良好的线性关系，符合朗伯-比尔定律，线性回归得方程；A=0．30761C（mg·L^-1）-0．01825，R=0．9986，摩尔吸光系数：2．01×10^4L·mol^-1·cm^-1．该方法重现性良好，误差〈3．31％，相对标准偏差：1．92％，平均回收率：99．55％．

In methanol solvent, Zn^2＋ can form a stable blue chelate complex with zincon,this is a basis for the determination of zinc in ionic liquid （ 1 - butyl- 3 - methylimdazolium tetrafluoroborate） by spectrophotometery. The concentration of Zn^2＋ （from 0. 324 mg· L^-1 to 0. 891 mg · L^-1 ） and its absorbance show a better linear relationship, which accords with Lambert - Beer＇s law. At measure wavelength 639 nm, the linear regression equation is A=0. 307 61 C（mg·L^-1 ）-0. 018 25, R= 0. 998 6,with molar absorptivity is 2.01×10^4L·mol^-1·cm^-1. The repeatability is satisfactory, the error is less than 3.31%, the relative standard deviation is 1.92%, the average percent recovery is 99.55%.