Trace determination of cadmium in plasma and urine using in situ solvent formation ionic liquid-assisted microextraction coupled with graphite furnace atomic absorption spectrometry

The human body is ineffective in removing heavy metals such as cadmium, so determination of trace amounts of heavy metals in biological fluids is essential. In this study, fast and sensitive in-situ solvent formation ionic liquidassisted microextraction method, using a very small sample volume was used to extract trace amounts of Cd2+ from plasma and urine samples, followed by determination with graphite furnace atomic absorption spectrometry. The ionic liquid 1-allyl-3-methylimidazolium bromide (AMIM-Br) was synthesized and for the first time used for extraction. The optimum amount of ionic liquid (29.20 mg), pH (3.04), O,O '-diethyl dithiophosphate concentration (0.02 M) and NaPF6 (94.74 mg) with an extraction efficiency of 97.80 % were obtained using box-Behnken design (BBD) based on response surface methodology (RSM). Under the optimum experimental conditions, the detection limit and enhancement factor were 0.35 ng/L and 95, respectively, with a linear range of 1-100 ng/L and R-2 = 0.9946. This method was successfully used for the determination of Cd2+ in biological samples with a recovery of 91.20-97.60 %. The relative standard deviation (RSD) for urine and plasma samples was <3.69 % and <4.16 %, respectively.