基于配位增强效应均相活化过氧单硫酸盐的比色法检测钴离子(Ⅱ)  

Colorimetric Detection of Co^(2+) Based on Ligand Effect Enhancementfor Homogeneous Activation of Peroxymonosulfate

作　　者：明闰勉 张才灵 谢良波 尚登辉 李轶[1] MING Run-Mian;ZHANG Cai-Ling;XIE Liang-Bo;SHANG Deng-Hui;LI Yi(School of Science,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学理学院,天津300072

出　　处：《分析化学》2021年第9期1515-1522,共8页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.21874099);天津市自然科学基金项目(No.20YFZCSN01070)资助。

摘　　要：钴在人体中具有重要作用,但高浓度的钴会引起一系列疾病。过氧单硫酸盐(PMS)是一种具有不对称结构的氧化剂,一定浓度的Co^(2+) 可催化活化PMS产生活性自由基。Co^(2+) 与Ac^(-) 之间有配位增强效应,向Co^(2+) -PMS体系中引入给电子体Ac^(-) 可加快电子传递,从而增强Co^(2+) 对PMS的催化活性,产生更多的硫酸根自由基(SO·-4)和羟基自由基(·OH),进而增强氧化3,3′,5,5′-四甲基联苯胺(TMB)的能力。基于Co^(2+) 对PMS均相催化活化能力以及Ac^(-) 的配位增强效应,本研究设计了一种无需催化剂的绿色高效的Co^(2+) 比色检测方法。在优化的条件下,即1.0 mmol/L NaAc、0.4 mmol/L TMB和0.3 mmol/L PMS,温度为25℃的条件下,Co^(2+) 浓度在0.5~3.0μmol/L范围内与体系在652 nm处的吸光度(A 652 nm)呈良好的线性关系,检出限(S/N=3)为29 nmol/L。本方法检测Co^(2+) 的特异性良好,与其它检测Co^(2+) 的方法相比,无需使用大型仪器,不需要复杂的操作过程,可快速、高效、绿色地实现Co^(2+) 的检测。Cobalt ion(Co^(2+) )plays an important role in human body.But high concentration of Co^(2+) can cause a series of diseases.Peroxymonosulfate(PMS)is an oxidant with an asymmetric structure,and a certain concentration of Co^(2+) can catalyze the activation of PMS to produce active free radicals.Studies have shown that there is ligand effect between Co^(2+) and Ac^(-) .The introduction of electron donor Ac^(-) into Co^(2+) -PMS accelerates electron transfer,so the catalytic activity of Co^(2+) towards PMS is enhanced and more sulfate radical(SO·-4)and hydroxyl radical(·OH)are produced,which results in corresponding enhancement of the ability of 3,3′,5,5′-tetramethylbenzidine(TMB)oxidation.Based on the homogeneous catalytic activity of Co^(2+) on PMS and the enhanced coordination effect of Ac^(-) ,a novel,catalyst free,green and efficient colorimetric detection method for Co^(2+) was designed in this work.When the concentrations of NaAc,TMB and PMS were 1.0,0.4 and 0.3 mmol/L,respectively,and the temperature was set at 25℃,the method was specific for the detection of Co^(2+) and had good anti-interference ability for 20 kinds of interfering ions.The concentration of Co^(2+) in the concentration range of 0.5-3.0μmol/L showed a good linear relationship with the absorbance of the system at 652 nm(A 652 nm),and the detection limit(S/N=3)was calculated to be 29 nmol/L.Compared with other detection methods for Co^(2+) ,this method established a fast,efficient and green platform for Co^(2+) detection without synthetic materials,large instruments and complex operation procedures.

关 键 词：过氧单硫酸盐 钴离子(Ⅱ) 比色检测 配位效应 

分 类 号：O657.3[理学—分析化学] X830.2[理学—化学]