State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing 210023, China.
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing 210023, China.
Talanta. 2019 Apr 1;195:173-180. doi: 10.1016/j.talanta.2018.11.043. Epub 2018 Nov 14.
Carboxyl-group functionalized mesoporous silica (CFMS) prepared by one-pot co-condensation method was employed for the solid phase extraction (SPE) of chromium species for the first time. A new approach of SPE coupled to inductively coupled plasma mass spectrometry (ICP-MS) was thus established for the speciation of chromium in environmental water samples. The influences of pH, volume of sample, extraction time, amount of adsorbent, elution conditions, co-existing ions and adsorption capacity were investigated on adsorption or elution of chromium species. Cr(VI) was not retained on the CFMS material in the pH range of 1.0-9.0, while Cr(III) was quantitatively adsorbed at pH 5.0-9.0. The captured Cr(III) was enriched by using 1.5 mol L HNO as elution solvent and detected by ICP-MS. Under the optimized SPE conditions, the maximum adsorption capacity of the CFMS for Cr(III) was 57.67 mg g and the enrichment factor was 25, with the detection limit (LOD) of 0.02 μg L. The proposed protocol has been successfully applied to chromium speciation in rain, lake and river water samples, which exhibited a prospect in field separation and enrichment of chromium species in environmental waters.
采用一锅共缩合法制备了羧基功能化介孔硅（CFMS），首次将其用于铬形态的固相萃取（SPE）。因此，建立了一种将 SPE 与电感耦合等离子体质谱（ICP-MS）相结合的新方法，用于环境水样中铬的形态分析。考察了 pH 值、样品体积、萃取时间、吸附剂用量、洗脱条件、共存离子和吸附容量等因素对铬形态吸附或洗脱的影响。在 pH 值为 1.0-9.0 的范围内，CFMS 材料对 Cr(VI)没有保留，而 Cr(III)在 pH 值为 5.0-9.0 时被定量吸附。使用 1.5 mol·L 的 HNO 作为洗脱溶剂可以富集被捕获的 Cr(III)，然后用 ICP-MS 进行检测。在优化的 SPE 条件下，CFMS 对 Cr(III)的最大吸附容量为 57.67 mg·g，富集因子为 25，检测限（LOD）为 0.02 μg·L。该方法已成功应用于雨水、湖水和河水样品中的铬形态分析，为环境水样中铬形态的现场分离和富集提供了一种有前景的方法。
