An alternative method of extracting of trace Hg(II) in water samples using Fe3O4@ quillaja Sapogenin on Ambersorb 572 and determination by CVAAS

A functionalized Ambersorb 572 with Fe₃O₄@ quillaja Sapogenin material has been studied on pre-concentration and determination of trace mercury. In this process, the effects of solution pH solution, elution conditions on pre-concentration of trace mercury were studied and the effect of interfering ions was also investigated.A cold vapor atomic absorption spectrophotometric (CVAAS) method for the determination of trace Hg(II) after adsorption of Fe₃O₄@ quillaja Sapogenin chelate on Ambersorb 572 has been developed. This chelate is adsorbed on the adsorbent in the pH range 2-7.5. The Hg(II) chelate is eluted with 5ml of 0.1 mol l⁻¹ potassium cyanide and determined by cold vapor atomic absorption spectrometry (CVAAS). The selectivity of the proposed procedure was also evaluated. Results show that iron(III), zinc(II), nickel(II),manganese(II) and cobalt(II) at the 50µg l⁻¹ level and sodium(I), potassium(I), magnesium(II), calcium(II) and aluminium(III) at the 1000µg l⁻¹ level did not interfere. A high enrichment factor, 200, was obtained. The detection limit (3σ) of Hg(II) was 0.27µg l⁻¹. The precision of the method, evaluated by seven replicate analyses of solutions containing 5µg of Hg(II) was satisfactory and the relative standard deviation was 2.2%. The adsorption of Hg(II) onto Ambersorb 572 can formally be described by a Langmuir equation with a maximum adsorption capacity of 14.3 mg g⁻¹ and a binding constant of 0.00578 lmg⁻¹. The method was applied to the extraction and recovery of Hg(II) in different water samples.