Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang 110819, China.
Talanta. 2012 Jun 15;95:31-5. doi: 10.1016/j.talanta.2012.03.038. Epub 2012 Mar 29.
A novel adsorbent was developed by coating Mg-FeCO(3) layered double hydroxides (LDHs) on cellulose fibre. The LDHs take up significant amount of selenite and selenate in a wide pH range with similar sorption capacities (pH 3.8-8.0 for selenite and pH 5.8-7.0 for selenate). A mini-column packed with Mg-FeCO(3) LDHs layer coated cellulose fibre particles was incorporated into a sequential injection system for uptake of selenite at pH 6.0. The retained selenite was afterwards collected with 70 μ L of 0.8%(m/v) NaOH as eluent, followed by hydride generation and atomic fluorescence spectrometric detection. Total inorganic selenium was adsorbed at pH 6.0 by the LDHs-cellulose fibre mini-column after selenate was pre-reduced to selenite by 2.0 mol L(-1) HCl at 80°C, and selenium speciation was performed by difference. With a sample volume of 1.0 mL, an enrichment factor of 13.3 was derived with a detection limit of 11 ng L(-1) within a linear range of 0.04-4.0 μg L(-1). A relative standard deviation (RSD) of 3.3% (0.5 μg L(-1), n=11) was achieved. The procedure was validated by analyzing selenium in a certified reference material GBW 10010 (rice), and speciation of inorganic selenium in natural water samples.
一种新型吸附剂是通过将 Mg-FeCO(3) 层状双氢氧化物 (LDHs) 涂覆在纤维素纤维上来制备的。在很宽的 pH 范围内，LDHs 会吸收大量的亚硒酸盐和硒酸盐，并且具有相似的吸附容量（亚硒酸盐为 pH 3.8-8.0，硒酸盐为 pH 5.8-7.0）。一个填充有 Mg-FeCO(3) LDHs 涂层纤维素纤维颗粒的微型柱被纳入顺序注射系统中，用于在 pH 6.0 下吸收亚硒酸盐。保留的亚硒酸盐随后用 70 μ L 0.8%（m/v）NaOH 作为洗脱液收集，随后进行氢化物发生和原子荧光光谱检测。总无机硒在 pH 6.0 下被 LDHs-纤维素纤维微型柱吸附，在此之前，硒酸盐在 80°C 下用 2.0 mol L(-1) HCl 预先还原为亚硒酸盐，并用差减法进行硒形态分析。在 1.0 mL 样品体积下，富集因子为 13.3，检测限为 11 ng L(-1)，线性范围为 0.04-4.0 μg L(-1)。相对标准偏差 (RSD) 为 3.3%（0.5 μg L(-1)，n=11）。该方法通过分析认证参考物质 GBW 10010（大米）中的硒和天然水样中的无机硒形态进行了验证。
