Development of Ionic Liquid-based Magnetic Nanoparticle-supported Dispersive Liquid Liquid Microextraction Technique for Mercury Preconcentration Prior to Hydride Generation Atomic Absorption Spectrometry in Aqueous Samples

A simple and efficient ionic liquid-based magnetic nanopartide-supported dispersive liquid liquid microextraction (IL-mDLLME) method was developed to enrich mercury before its determination by flow injection-hydride generation atomic absorption spectrometry. In this experiment, limidazolium hexa-flurophosphate ionic liquid, having different cationic groups as 1-allyl/butyl/methyl, was used to extract mercury-4-(2-pyridylazo) resorsinol complex from aqueous samples into fine droplets. After adding of Fe3O4 MNPs to the extraction media, enriched mercury was separated from the aqueous solution using an external magnet. Some analytical parameters influencing the efficiency of the proposed (IL-mDMME) method, such as pH, amount of IL, ligand concentration, extraction time, amount of Fe3O4 MNPs, sample volume and matrix effect, were optimized. Under the optimized conditions, good linearity was obtained with correlation coefficients (r) greater than 0.9938. The repeatability and reproducibility of the proposed method were found to be good, and the limits of detection ranged from 0.18 mu g L-1 to 0.54 mu g L-1 for the studied ionic liquids. The accuracy of the proposed method, was assessed by standard addition method calculated by relative standard deviations in the range of 100-110% for tap water and 97-100% for mineral water. Within this extraction technique, fast, green, and efficient enrichment of mercury was achieved by centrifugation steps using environmentally friendly ionic lquids and obtaining high enrichment factors.