Laboratory of Analytical Chemistry for Research and Development (QUIANID), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Instituto Interdisciplinario de Ciencias Básicas (ICB), UNCUYO-CONICET, Padre J. Contreras 1300, 5500, Mendoza, Argentina.
Anal Bioanal Chem. 2018 Jul;410(19):4715-4723. doi: 10.1007/s00216-018-1050-6. Epub 2018 Apr 19.
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]FeCl) 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 HNO 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 Cd, while the relative standard deviation (RSD) was 3.8% (at 2 μg L Cd and n = 10), calculated from the peak height of absorbance signals. This work reports the first application of the MIL [P]FeCl along with the DLLME technique for the successful determination of Cd at trace levels in different honey samples. Graphical abstract Preconcentration of ultratraces of Cd in honey using a magnetic ionic liquid and dispersive liquid-liquid microextraction technique.
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、批量和无需离心的分散液液微萃取方法，用于蜂蜜中痕量 Cd 的测定。最初，在 pH 0.5 下，Cd(II)与二乙二硫代磷酸铵（DDTP）螯合，然后用磁性 MIL 三己基（十四烷基）磷酸铁（III）([P]FeCl)和乙腈作为分散剂萃取。仅使用磁铁即可将含有分析物的 MIL 相与水相分离。采用稀释 HNO3 从 MIL 相中反萃取 Cd，将该溶液直接注入 ETAAS 仪器的石墨炉中。在最佳实验条件下，获得了 93%的萃取效率和 112 的灵敏度增强因子。在 2 μg L Cd 和 n=10 的条件下，检测限（LOD）为 0.4 ng L Cd，通过吸光度信号的峰值高度计算得出，相对标准偏差（RSD）为 3.8%。本工作首次报道了 MIL [P]FeCl 与 DLLME 技术结合，成功用于不同蜂蜜样品中痕量 Cd 的测定。
