Preconcentration of molybdenum in water samples using coconut husk

The hydrogeochemical survey for uranium is done not only for the determination of uranium but also that of other geochemically important elements Cu, Co, Ni, Pb, Cd, Cr, Zn, Mo and V that are likely to accompany uranium. They play an important role as they are useful in the understanding of petro-genetic and ore-genetic processes. These elements also accompany uranium in its various types of deposits and therefore can be used in geochemical surveys as pathfinder elements. For sandstone type and vein type uranium deposits, Mo acts as one of the pathfinder elements. Since Mo is present at the nanogram level in the hydrogeochemical samples, various pre-concentration techniques such as liquid-liquid extraction, ion-exchange separation, coprecipitation and solid phase extraction can be used. Use of different types of abundant biological materials such as chitin, chitosan, saw dust, biomass, vegetable mass etc. as solid phase extractants has gained popularity for the preconcentration of metals like Mo due to its flexibility, higher enrichment factor, absence of emulsions, rapidity and cost effectiveness. In the present study, coconut husk, an agricultural waste, has been thoroughly investigated for the pre-concentration of Mo in hydrogeochemical samples prior to its analysis. This material has been used by other workers for the removal of toxic metal ions such as Cd, Cr, Hg, Pb, Cu and As for environmental protection. Pre-concentrated molybdenum, after adsorption, has been leached with suitable reagent and then analyzed by ICP-OES