半胱氨酸螯合-浊点萃取-原子吸收光谱法测定痕量金属元素  

Development of Microchip-based Cloud Point Extraction System and Application to the Determination of Trace Metal in Water

作　　者：周晓[1] 贾庚[2] 张勋[1] 李析蒨[2] 卢利军[1] 赵韫慧[1] 

机构地区：[1]吉林出入境检验检疫局,吉林长春130062 [2]吉林大学中日联谊医院,吉林长春130033

出　　处：《化学试剂》2014年第7期632-636,共5页Chemical Reagents

摘　　要：选用L-半胱氨酸作为螯合剂，聚氧乙烯基壬基苯醚（PONPE 7．5）作为表面活性剂，建立了浊点萃取分离富集痕量过渡金属元素锌、钴、镍、铅的方法。结合火焰原子吸收光谱法，考察了各种实验条件的影响。在优化的实验条件下（样品pH8．0；螯合剂浓度2．67×10μmol／L；表面活性剂浓度0．33g／L；平衡温度30℃；平衡时间20rain），计算了方法的检出限、相对标准偏差。方法对锌、钴、镍、铅的检出限分别为1．2、1．5、1．6、2．8μg／L，相对标准偏差为2．0％～4．3％。将此方法用于环境水样和果汁样品中4种金属元素的测定，回收率80％－106％。In this work,cloud point methodology was success- fully employed for the preconcentration of trace level of zinc （Zn） ,cobalt（Co） , nickel（Ni） , and lead（Pb）. The method was based on the formation of extractable complexes of Zn, Co,Ni, and Pb with L-cysteine as the chelating reagent and poly （ ethylene glycol） mono-p-nonylphenyl ether （ PONPE 7.5） as the surfactant. Combined with flame atomic absorption spectrometry, the chemical variables affecting the cloud point extraction were optimized for the best extraction efficien- cy. Under the optimum conditions （pH 8. 0; chelating agent concentration 2.67 x 10-4 tool/L; surfactant concentration 0. 33 g/L; equilibration temperature 30 ℃ ;incubation time 20 min） ,limits of detection were 1.2,1.5,1.6, and 2. 8 μg/L for Zn, Co, Ni and Pb, respectively, with relative standard deviations （RSD） in the range of 2. 0% -4.3%. The developed method was applied to the determination of trace Zn, Co, Ni, and Pb in environmental water and fruit juice samples with recovery resuhs of 80% - 106%.

关 键 词：浊点萃取 痕量金属元素 L-半胱氨酸 原子吸收光谱法 

分 类 号：O657.31[理学—分析化学]