Yilmaz Vedat, Yilmaz Hayriye, Arslan Zikri, Leszczynski Jerzy
Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA; Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri, Turkey.
Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA; Deparment of Biomedical Devices and Technologies, Kayseri Vocational School, Erciyes University, Kayseri, Turkey.
Anal Lett. 2017;50(3):482-499. doi: 10.1080/00032719.2016.1182544. Epub 2016 May 24.
A novel Cd(II)-imprinted polymer was prepared with chemical immobilization approach by using N-methacryloyl-L-histidine as a vinylated chelating agent for on-line solid phase extraction of Cd(II) for determination by inductively coupled plasma mass spectrometry. Cd(II)-monomer complex was synthesized and copolymerized via bulk polymerization method in the presence of ethyleneglycoldimethacrylate cross-linker. The resulting polymer was leached with 1.0 mol L HNO to generate the cavities in the polymer for Cd(II) ions. The experimental conditions, including load pH, solution flow rate, and eluent concentration for effective sorption of Cd(II) were optimized using a minicolumn of the imprinted polymer. A volume of 5.0 mL sample 5 μg L Cd(II) solution at pH 6.5 was loaded onto the column at 2.0 mL min by using a sequential injection system (FIALab 3200) followed by elution with 1.0 mL of 0.75 mol L HNO. The relative selectivity coefficients of the imprinted polymer for Cd(II) were 38.5, 3.5, 3.0, 2.5 and 6.0 in the presence of Cu(II), Ni(II), Zn(II), Co(II) and Pb(II), respectively. Computational calculations revealed that the selectivity of the imprinted polymer was mediated by the stability of Cd(II)-N-methacryloyl-L-histidine complex which was far more stable than those of commonly used monomers, such as 4-vinyl pyridine, methacrylic acid and vinylimidazole. The detection limit (3s) and relative standard deviation (%) were found to be 0.004 μg L and 3.2%, respectively. The method was validated by analysis of seawater certified reference material (CASS-4) and successfully applied to the determination of Cd(II) in coastal seawater and estuarine water samples.
采用化学固定法，以N-甲基丙烯酰基-L-组氨酸作为乙烯基化螯合剂，制备了一种新型的镉（II）印迹聚合物，用于在线固相萃取镉（II），并通过电感耦合等离子体质谱法进行测定。在乙二醇二甲基丙烯酸酯交联剂存在下，通过本体聚合法合成并共聚镉（II）-单体配合物。用1.0 mol/L硝酸浸提所得聚合物，以在聚合物中产生用于镉（II）离子的空穴。使用印迹聚合物微型柱对有效吸附镉（II）的实验条件进行了优化，包括负载pH值、溶液流速和洗脱液浓度。通过顺序注射系统（FIALab 3200），将5.0 mL pH为6.5、含5 μg/L镉（II）溶液的样品以2.0 mL/min的流速加载到柱上，随后用1.0 mL 0.75 mol/L硝酸洗脱。在铜（II）、镍（II）、锌（II）、钴（II）和铅（II）存在下，印迹聚合物对镉（II）的相对选择性系数分别为38.5、3.5、3.0、2.5和6.0。计算结果表明，印迹聚合物的选择性是由镉（II）-N-甲基丙烯酰基-L-组氨酸配合物的稳定性介导的，该配合物比常用单体如4-乙烯基吡啶、甲基丙烯酸和乙烯基咪唑的配合物稳定得多。检测限（3s）和相对标准偏差（%）分别为0.004 μg/L和3.2%。该方法通过对海水标准物质（CASS-4）的分析进行了验证，并成功应用于沿海海水和河口水样中镉（II）的测定。
