摘要
提出了一种测定微量镉的新萃取光度法。在pH 10.8的Na2B4O7-NaOH缓冲介质中,1-(4-硝基苯基)-3-(4-苯基偶氮苯基)-三氮烯(Cadion)与Cd2+形成的Cd-Cadion络合物可被少量离子液体(1-丁基-3-甲基咪唑六氟磷酸盐[Bmim][PF6])萃取,经离心分离后,在最大吸收波长517nm处,用分光光度法直接测定离子液体相中镉含量。方法的线性范围为1.0～62.5ng/mL,检出限为0.22ng/mL,表观摩尔吸收系数为6.9×105 L.mol-1.cm-1,增强因子为29.5倍,相对标准偏差RSD(50ng/mL,n=6)为2.1%。该方法直接用于水样中微量镉的测定,其回收率为96.7%～108.5%。
A new extraction spectrophotometry for the determination of micro-cadmium was proposed. In Na2B4O7-NaOH buffer medium at pH 10.8, the Cd-Cadion complex formed by 1-（4- nitrobenzo- phenone）-3-（4-phenylazophenyl）- triazene （Cadion） and Cd2＋ could be extracted by little ionic liquid （1-butyl-3-methylimidazole hexafluorophosphate, [Bmim][PF6]）. After centrifugal separation, the content of cadmium in ionic liquid phase was directly determined by speetrophotometry at maximum absorption wavelength （517 nm）. The linear range of this method was 1.0-62.5 ng/mL, the detection limit was 0.22 ng/mL, apparent molar absorptivity was 6.9 × 105 L ·mol^-1 @cm^-1, the enhancement factor was 29.5, and the relative standard deviation （RSD, 50 ng/mL, n=6） was 2.1 %. The proposed method was directly applied to the determination of micro-cadmium in water sample with recoveries of 96.7%-108.5 %.
出处
《冶金分析》
CAS
CSCD
北大核心
2012年第2期28-31,共4页
Metallurgical Analysis
关键词
离子液体
萃取
镉
镉试剂
分光光度法
ionic liquid
extraction
cadmium
cadion
spectrophotometry
