Determination of Cadmium in Fruit and Vegetables by Ionic Liquid Magnetic Microextraction and Flame Atomic Absorption Spectrometry

摘要

An ionic liquid-linked dual magnetic microextraction procedure is reported for cadmium(II) with flame atomic absorption spectrometry. Cadmium was complexed with pyrolidine dithiocarbamate and the chelate was extracted into the fine droplets of 1-butyl-3-methylimidazolium hexafluorophosphate by using a vortex mixer with Fe3O4 nanoparticles. Plackett-Burman design was used to optimize relevant parameters of the method, including the pH, the volume of ionic liquid, the amount of ammonium pyrolidine dithiocarbamate, the mass of magnetic nanoparticles, and the vortex time. The pH, volume of ionic liquid, and mass of ammonium pyrolidine dithiocarbamate significantly affected the recovery. The limit of detection, preconcentration factor, and relative standard deviation were 0.32 mu gL(-1), 80, and 3.4%, respectively. The procedure was validated by the analysis of spinach leaves standard reference material 1570a and recovery measurements. Practical application of the method involved the determination of cadmium in fruit and vegetables.