A simple, highly efficient, batch, and centrifuge-less dispersive liquid-liquid microextraction method based on a magnetic ionic liquid (MIL-DLLME) and electrothermal atomic absorption spectrometry (ETAAS) detection was developed for ultra-trace Cd determination in honey. Initially, Cd(II) was chelated with ammonium diethyldithiophosphate (DDTP) at pH 0.5 followed by its extraction with the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate(III) ([P_6,6,6,14]FeCl₄) and acetonitrile as dispersant. The MIL phase containing the analyte was separated from the aqueous phase using only a magnet. A back-extraction procedure was applied to recover Cd from the MIL phase using diluted HNO₃ and this solution was directly injected into the graphite furnace of ETAAS instrument. An extraction efficiency of 93% and a sensitivity enhancement factor of 112 were obtained under optimal experimental conditions. The detection limit (LOD) was 0.4 ng L⁻¹ Cd, while the relative standard deviation (RSD) was 3.8% (at 2 μg L⁻¹ Cd and n = 10), calculated from the peak height of absorbance signals. This work reports the first application of the MIL [P_6,6,6,14]FeCl₄ along with the DLLME technique for the successful determination of Cd at trace levels in different honey samples.

Open image in new window

建立了一种基于磁性离子液体（MIL-DLLME）和电热原子吸收光谱法（ETAAS）检测的简单，高效，分批，无离心的分散液-液微萃取方法，用于蜂蜜中的痕量Cd测定。最初，将Cd（II）与pH为0.5的二乙基二硫代磷酸铵（DDTP）螯合，然后将其用MIL己基（十四烷基）_{phosph四氯高铁酸根}（[P _6,6,6,14 ] FeCl ₄）和乙腈_萃取分散剂。仅使用磁体将含有分析物的MIL相与水相分离。应用反萃取程序，使用稀释的HNO ₃从MIL相中回收Cd然后将该溶液直接注入ETAAS仪器的石墨炉中。在最佳实验条件下，提取效率为93％，灵敏度增强因子为112。根据 吸光度信号的峰高计算，检出限（LOD）为0.4 ng L ^-1 Cd，相对标准偏差（RSD）为3.8％（在2μgL ^-1 Cd和n = 10时）。这项工作报告了MIL [P _6,6,6,14 ] FeCl ₄以及DLLME技术在不同蜂蜜样品中痕量水平的成功测定中的首次应用。

在新窗口中打开图像