Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
Talanta. 2015 Jan;131:266-72. doi: 10.1016/j.talanta.2014.07.054. Epub 2014 Jul 25.
Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L(-1) KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L(-1) with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L(-1), n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters.
环境水中无机砷、铬和硒的形态分析对于环境污染监测具有重要意义。本工作合成了 3-(2-氨乙基氨基)丙基三甲氧基硅烷(AAPTS)功能化多壁碳纳米管(MWCNTs)，并将其作为微柱固相萃取(SPE)-电感耦合等离子体质谱(ICP-MS)联用技术用于环境水中无机砷、铬和硒的同时形态分析。结果表明，在 pH 约为 2.2 时，As(V)、Cr(VI)和 Se(VI)可选择性地被填充有 AAPTS-MWCNTs 吸附剂的微柱吸附，而此时 As(III)、Cr(III)和 Se(IV)不能被保留而直接通过微柱。用 10.0 μmol L(-1) KMnO4将 As(III)、Cr(III)和 Se(IV)氧化为 As(V)、Cr(VI)和 Se(VI)后，测定总无机砷、铬和硒。As(III)、Cr(III)和 Se(IV)的测定基于分别从总 As、Cr 和 Se 中减去 As(V)、Cr(VI)和 Se(VI)。在优化条件下，对 As(V)、Cr(VI)和 Se(VI)的检出限分别为 15、38 和 16 ng L(-1)，相对标准偏差(RSD)分别为 7.4%、2.4%和 6.2%(c=1 µg L(-1)，n=7)。该方法通过分析四种标准参考物质、雨水、长江水和东湖水进行了验证。
