纳米钛富集水样重金属镉-胶体金免疫层析法快速检测方法的建立

研究了纳米TiO2分离富集水样中痕量镉的最佳反应条件,应用自制抗Cd(Ⅱ)-iEDTA(Isothiocya-nobenzyi-EDTA)螯合物的单克隆抗体,建立了快速检测环境水样中重金属镉残留的胶体金免疫层析法。采用纳米钛富集水样中的痕量镉,用洗脱剂将吸附的镉离子洗脱后,再采用胶体金免疫层析法快速判断镉离子浓度,进而分析水样中的重金属镉含量。结果表明,pH 9.0时,Cd可被纳米TiO2定量富集,吸附于纳米TiO2上的镉离子可用0.1 mol/L的EDTA.2Na(乙二胺四乙酸二钠)溶液定量脱附。在优化实验条件下,纳米TiO2对Cd的吸附容量为14.7 mg/g,富集倍数可达50倍。制备了比色法判定结果的胶体金试纸条,并建立了纳米TiO2富集-胶体金试纸条联用检测方法。对实测样品的检测耗时约90 min,该方法对Cd的定量下限可达5μg/L,适用于环境水样的检测。

Rapid Determination of Ion Cadmium in Water Samples by Nano-titanium Dioxide Preconcentration-Colloidal Gold Immunochromatographic Method

Based on our previous cadmium complete antigen coupling technology and anti-Cd(Ⅱ)-iEDTA(Isothiocyanobenzyi-EDTA) monoclonal antibody, the immuno-colloidal gold test strip was prepared and used for the detection of Cd(Ⅱ) in water samples.To improve the lower limit of quantification, Cd(Ⅱ) was preconcentrated with nanometer titanium dioxide and eluted with 0.1 mol/L EDTA·2Na quantitatively at pH 9.0. Under optimal conditions, the adsorption capacity of nano-TiO_2 for Cd(Ⅱ) was found to be 14.7 mg/g and the maximum preconcentration factor was 50. The lower limit of quantification for Cd was found to be 5 μg/L. The results obtained by the proposed method were in conformity with those obtained by ICP-AES method.