College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China.
College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China.
J Chromatogr A. 2022 Jun 21;1673:463112. doi: 10.1016/j.chroma.2022.463112. Epub 2022 May 3.
An effective and sensitive two-step stacking of arsenic species by electrokinetic injection and micelle-to-solvent stacking (MSS) using zwitterionic surfactant 3-(N,N-dimethylpalmitylammonio) propane sulfonate was successfully developed in a co-electro-osmotic flow (co-EOF) capillary zone electrophoresis (CZE). The fused silica capillaries were coated with 1% hexadimethrine bromide solution to satisfy the condition of the same EOF direction between the test anions and capillary. The background solution was 100 mM borax buffer (pH 9.2). The proposed method was performed by a CZE system equipped with a diode array detector, and the detection wavelength was monitored at 192 nm. The separation voltage was -20 kV. The group of micelles and target analytes was stacked by field-enhanced sample injection at -10 kV for 180 s. The second stacking step used 60% MeOH to serve as an organic solvent where the analytes were brought by the micelles to the MSS boundary. The enrichment factors of As(Ⅴ), As(Ⅲ), disodium methyl arsonate hexahydrate (MMA), and dimethylarsinic acid (DMA) were 1230, 840, 3820, and 1450, respectively, compared to typical injections in CZE. The limits of detection (S/N = 3) ranged from 0.382 to 0.911 ng mL. The intracapillary repeatabilities (%RSD, n = 3) were 0.5-1.0% for migration time and 0.3-0.7% for peak areas. The technology of two-step stacking by MSS in co-EOF CZE together with a simple extraction procedure for As(Ⅴ), As(Ⅲ), MMA and DMA were demonstrated in kelp and rice samples.
采用两性离子表面活性剂 3-（N，N-二甲基十六烷基）丙磺酸，成功开发了一种有效且灵敏的两步砷形态电动力学进样和胶束-溶剂堆积（MSS）堆积方法。在共电动流（co-EOF）毛细管区带电泳（CZE）中。将熔融石英毛细管用 1%十六烷基三甲基溴化铵溶液涂覆，以满足测试阴离子和毛细管之间相同 EOF 方向的条件。背景溶液为 100 mM 硼砂缓冲液（pH 9.2）。该方法在配备二极管阵列检测器的 CZE 系统中进行，检测波长在 192nm 处监测。分离电压为-20kV。通过在-10kV 下进行场增强样品进样，将胶束和目标分析物的混合物进行第一级堆积 180s。第二级堆积步骤使用 60%甲醇作为有机溶剂，将分析物通过胶束带入 MSS 边界。与 CZE 中的典型进样相比，砷（Ⅴ）、砷（Ⅲ）、二甲基砷酸二甲酯六水合物（MMA）和二甲基砷酸（DMA）的富集因子分别为 1230、840、3820 和 1450。与 CZE 中的典型进样相比，砷（Ⅴ）、砷（Ⅲ）、二甲基砷酸二甲酯六水合物（MMA）和二甲基砷酸（DMA）的富集因子分别为 1230、840、3820 和 1450。与 CZE 中的典型进样相比，砷（Ⅴ）、砷（Ⅲ）、二甲基砷酸二甲酯六水合物（MMA）和二甲基砷酸（DMA）的富集因子分别为 1230、840、3820 和 1450。检测限（S/N=3）范围为 0.382-0.911ngmL。迁移时间的毛细管内重复性（%RSD，n=3）为 0.5-1.0%，峰面积的重复性为 0.3-0.7%。共电动流 CZE 中的两步 MSS 堆积技术以及用于海带和大米样品中砷（Ⅴ）、砷（Ⅲ）、MMA 和 DMA 的简单提取程序已得到证明。
