Determination of total arsenic in water and food samples by pressure-induced ionic liquid-based dispersive liquid-liquid microextraction method prior to analysis by hydride generation atomic absorption spectrometry

A pressure-induced ionic liquid-based dispersive liquid-liquid microextraction (PI-IL-DLLME) method has been developed for the determination of total arsenic (As) in water and food samples. Quantitative analysis of total As in the water and food samples was performed by using hydride generation atomic absorption spectrometry. The complexing reagent diethyldithiocarbamate formed a strong hydrophobic complex with As at pH 4. the ionic liquid of 1-hexyl-3-methylimida-zolium bis(trifluoromethylsul-fonyl> imide was used as the extraction medium in the aqueous solution to increase the phase transfer ratio which significantly enhances recovery of the labile hydrophobic complex. Various experimental parameters such as pH, complexing reagent, ionic liquid, induced pressure, and centrifugation were optimized to achieve maximum recovery of the target analyte. The analytical parameters of limit of detection, limit of quantification and linear range were 0.016 μg L^-1, 0.055 μg L^-1, and 0.062-1.25 μg L^-1, respectively. The enhancement factor and relative standard deviation were found at 87.5 and 4.89%, respectively. Accuracy of the developed method was checked by analysis of certified reference materials of hard drinking water, tea, and rice flour. The proposed PI-IL-DLLME method was successfully applied for the determination of total As in groundwater, surface water, and different foods.