Chen Dahui, Huang Chaozhang, He Man, Hu Bin
Department of Chemistry, Wuhan University, Wuhan, China.
J Hazard Mater. 2009 May 30;164(2-3):1146-51. doi: 10.1016/j.jhazmat.2008.09.022. Epub 2008 Sep 13.
A simple and sensitive method using micro-column packed with 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) modified ordered mesoporous silica combined with inductively coupled plasma optical emission spectrometry (ICP-OES) for the speciation of inorganic arsenic (As(III) and As(V)) has been developed. The adsorption behaviors of As(III) and As(V) on AAPTS modified ordered mesoporous silica were investigated. It was found that As(V) can be selectively adsorbed on the micro-column within pH of 3-9, while As(III) could not be retained in the studied pH range and passed through the micro-column directly. Total inorganic arsenic was extracted after the oxidation of As(III) to As(V) with 50.0 micromol L(-1) KMnO(4). The assay of As(III) was based on subtracting As(V) from total As. The effect of various parameters on the separation/preconcentration of As(III) and As(V) have been investigated and the optimal experimental conditions were established. The adsorption capacity of AAPTS modified ordered mesoporous silica for As(V) was found to be 10.3 mg g(-1). The detection limit of the method for As(V) was 0.05 microg L(-1) with an enrichment factor of 100, and the relative standard deviation (R.S.D.) was 5.7% (n=7, C=1.0 microg L(-1)). In order to validate the developed method, a certified reference material GSBZ50004-88 environmental water sample was analyzed and the determined values were in good agreement with the certified values. The proposed method was successfully applied to the speciation analysis of inorganic arsenic in natural water samples.
已开发出一种简单且灵敏的方法，该方法使用填充有3-(2-氨乙基氨基)丙基三甲氧基硅烷（AAPTS）修饰的有序介孔二氧化硅的微柱，并结合电感耦合等离子体发射光谱法（ICP-OES）用于无机砷（As(III)和As(V)）的形态分析。研究了As(III)和As(V)在AAPTS修饰的有序介孔二氧化硅上的吸附行为。结果发现，在pH值为3 - 9的范围内，As(V)可被选择性吸附在微柱上，而在研究的pH范围内As(III)不能被保留，直接通过微柱。用50.0 μmol L⁻¹的KMnO₄将As(III)氧化为As(V)后，提取总无机砷。As(III)的测定基于从总砷中减去As(V)。研究了各种参数对As(III)和As(V)分离/预富集的影响，并确定了最佳实验条件。发现AAPTS修饰的有序介孔二氧化硅对As(V)的吸附容量为10.3 mg g⁻¹。该方法对As(V)的检测限为0.05 μg L⁻¹，富集因子为100，相对标准偏差（R.S.D.）为5.7%（n = 7，C = 1.0 μg L⁻¹）。为验证所开发的方法，分析了一种有证标准物质GSBZ50004 - 88环境水样，测定值与认证值吻合良好。所提出的方法成功应用于天然水样中无机砷的形态分析。
