Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, PR China.
Talanta. 2011 May 15;84(3):679-83. doi: 10.1016/j.talanta.2011.01.072. Epub 2011 Feb 4.
Analysis of metal ions in environment is of great importance for evaluating the risk of heavy metal to public health and ecological safety. A method for simultaneous determination of metal ions in water samples was developed by using adsorption preconcentration and near-infrared diffuse reflectance spectroscopy (NIRDRS). A high capacity adsorbent of thiol-functionalized magnesium phyllosilicate, named Mg-MTMS, was prepared by co-condensation for preconcentration of Hg(2+), Pb(2+) and Cd(2+) in aqueous solutions. After adsorbing the analytes onto the adsorbent, NIRDRS was measured and PLS models were established for fast and simultaneous quantitative prediction. Because the interaction of the ions with the functional group of the adsorbent can be reflected in the spectra, the models built with the samples prepared by river water were proven to be efficient enough for precise prediction. The determination coefficients (R(2)) of the validation samples for the three ions were found as high as 0.9197, 0.9599 and 0.9861, respectively. Furthermore, because the high adsorption efficiency of Mg-MTMS, the detected concentrations are as low as milligrams per liter for the three ions, and the concentration can be further reduced. Therefore, the feasibility of quantitative analysis metal ions in river water by NIRDRS is proven and this may provide a new way for fast simultaneous determination of trace metals in environmental waters.
分析环境中的金属离子对于评估重金属对公众健康和生态安全的风险非常重要。本研究采用吸附预富集和近红外漫反射光谱（NIRDRS）联用的方法，建立了一种同时测定水样中金属离子的方法。通过共缩聚合成了一种巯基功能化的镁层状硅酸盐高容量吸附剂，命名为 Mg-MTMS，用于水溶液中 Hg(2+)、Pb(2+)和 Cd(2+)的预富集。在将分析物吸附到吸附剂上后，测量 NIRDRS 并建立 PLS 模型以快速、同时进行定量预测。由于离子与吸附剂官能团的相互作用可以反映在光谱中，因此用河水制备的样品建立的模型被证明足以进行精确预测。三种离子的验证样品的决定系数（R(2)）分别高达 0.9197、0.9599 和 0.9861。此外，由于 Mg-MTMS 的高吸附效率，三种离子的检测浓度低至毫克/升，并且可以进一步降低浓度。因此，证明了通过 NIRDRS 对河水进行定量分析金属离子的可行性，这可能为环境水中痕量金属的快速同时测定提供一种新方法。
