Ultrasound assisted emulsification microextraction for selective determination of trace amount of mercury(II)

Abstract

An environmental friendly sample pre-treatment method, ultrasound assisted emulsification microextraction, followed by furnace atomic absorption spectrometry is reported for the selective determination of mercury(II). Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, volume of chelating agent, sample pH, extraction time, temperature and addition of salt, are optimized. Under the optimum conditions for extraction recovery, 80 µL of tetrachloroethylene as extraction solvent and 1000 µL of [4-benzylidenamino- 3,4 dihydro-6-methyl 3-thioxo-1,2,4-triazin-5(2H)-one] as complexing agent give the best results. Under the optimum conditions, the calibration curve is linear in the range of 100-800 µg L^-1, relative standard deviation is 2.8% for five analysis of sample solution containing 0.3 mg L⁻¹ Hg(II) with the limit of detection of 0.043 mg L^-1_. The method has been applied successfully for assessing matrix effect by analysis of non- piked and spiked real samples. The results demonstrate a successful robustness of the method for quantitative and selective determination of trace amount of mercury(II) in water and wastewater samples with relative recovery of 96-103%.