Abstract
8-Hydroxyquinoline (8-HQ) functionalized sol-gel silica (HQSG) was prepared and investigated as a solid phase extractant for mercury from aqueous solutions. Various parameters: effect of pH, contact time, effect of foreign ions and complexing agents that could influence the extraction have been studied at room temperature. Fast equilibration was observed and equilibration was achieved in less than five minutes. The maximum sorption capacity of Hg+2 on to HQSG from non-competitive solutions at pH 6 was found 0.066 mM g(-1). The adsorption data was best fitted to Langmuir adsorption isotherm. Extraction data from effect of foreign ions on the extraction of mercury shows that the proposed sorbent has reasonable selectivity for mercury against various metal ions. Extraction route and stripping of the extracted mercury with different solutions have been discussed. HQSG has been compared with some reported alternate sorbents investigated for solid phase extraction of mercury.