DETERMINATION OF MERCURY BY SUBSTOICHIOMETRIC ISOTOPE-DILUTION ANALYSIS

A radiometric method based on Substoichiometric Isotope Dilution Analy sis has been developed for the determination of trace amounts of mercu ry using alpha-Thiopicolin-o-anisylamide (TPA) as a substoichiometric reagent. A preconcentration procedure has also been developed based on the adsorption of mercury(II) as a dithizone complex onto microcrysta lline naphthalene which when used in conjunction with the proposed rad iometric method enhances its sensitivity and selectivity. As low as 0. 2 mug of mercury could be determined in an aqueous phase volume of 80 ml. The method has been successfully applied for the determination of trace amounts of mercury in city waste incineration ash, zinc metal an d cadmium oxide samples.