磁性固相萃取-石墨炉原子吸收光谱法联用分析水样中痕量镍

Determination of trace amounts of nickel by graphite furnace atomic absorption spectrometry with magnetic solid-phase extraction

建立了磁性固相萃取联用石墨炉原子吸收光谱仪检测水中痕量Ni的方法。通过共沉淀法制备磁性碳纳米材料，用以富集了水样中的Ni2＋，并使用石墨炉原子吸收光谱法进行检测。对影响萃取效率的主要因素，包括溶液pH、样品流速、样品体积、洗脱液浓度和体积等条件进行了优化。在最优实验条件下，Ni在0．01-5μg／L内呈良好线性，RSD为3．6％（1．0μg／L，n=11），检出限低至1．8ng／L，富集因子可达到80。方法已用于标准物质和实际样品中Ni的快速检测。

A method for the determination of trace amounts of Ni by magnetic solid-phase extraction （MSPE）coupled with graphite furnace atomic absorption spectrometry （GFAAS） was successfully proposed. A novel type of magnetic multiwalled carbon nanotubes has been successfully synthesized and was applied as an effective sorbent material for the pre-concentration of nickel. Different parameters such as sample pH value, the flow rate of sample, sample volume, eluent concentration and volume were investigated to enhance the analytical performance. The calibration curve was linear in the concentration range of 0. 01 to 5 μg/L. The relative standard deviation was 3.6% at the 1.0 μg/L level （ n = 11 ）. The enhancement factor of the proposed method for nickel was 80. The limit of detection was as low as 1.8 ng/L. The proposed method is reliable, time saving and rapid, and has been used successfully in the determination of traces of nickel in standard and real samples.