Selective pre - concentration and solid phase extraction of mercury ( II ) from natural water by alumina - loaded ammonium pyrrolidine dithiocarbamate phases

Alumina phase loaded with ammonium pyrrolidine dithiocarbamate (APDC )were synthesized based on chemical binding and physical adsorption approaches. The stability of a chemically modified APDC especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of alumina immobilized APDC phase. The application of this alumina for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing alumina phases. Hg(II) was found to exhibit the highest affinity towards extraction by these alumina phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (K d ) of all the metal ions, showing the highest value reported for mercury(II) to occur by alumina immobilized APDC phase. The potential applications of alumina immobilized APDC phase for selective extraction of mercury(II) to occur from aqueous solution were successfully accomplished as well as preconcentration of low concentration of Hg(II) (22 pg ml) from natural tap water with a pre-concentration factor of 200 for Hg(II) off-line analysis by cold vapor atomic absorption analysis.  2008 Trade Science Inc. INDIA Trade Science Inc. ACAIJ, 7(2) 2008 [62-68] Full Paper An Indian Journal Volume 7 Issue 2 January 2008 Analytical CHEMISTRY