Separation and removal of mercury(II) from water samples using (acetylacetone)-2-thiol-phenyleneimine immobilized on anion-exchange resin prior to determination by cold vapor inductively coupled plasma atomic emission spectroscopy

Abstract

(Acetylacetone)-2-thiol-phenyleneimine (H2L) immobilized on an anion-exchange resin (Dowex) was used for separation and removal of mercury from natural water samples and for preconcentration prior to its determination by cold vapor inductively coupled plasma atomic emission spectroscopy. The metal was eluted from the column using a solution of 10% thiourea in 0.1 M HCl. The modified resin is higly selective with an exchange capacity of 1.60 mmol g(-1) . Various parameters like pH, column flow rate, and desorbing agents are optimized. The proposed method has a linear calibration range of 15-1000 ng/ml Hg(II), with a relative standard deviation at the 15 ng/ml level of 3.5%. The precision of the method (evaluated as the relative standard deviation obtained after analyzing six series of five replicates) was 4.2% at the 50 ng/ml level of Hg(II). The method has been used for routine determination of trace levels of mercury species in natural waters. The potential application of modified resin for the removal of mercury(II) from two natural water samples (top water and lake water) spiked with 50 ng/ml of mercury (II) was studied by ICP-AES, and the results proved that excellent percent extraction of mercury(II) from both natural water samples was obtained by column method using modified resin.