Adsorptive cathodic stripping voltammetric determination of molybdenum in synthetic solutions and environmental samples

A sensitive and selective voltammetric methods has been developed for the d etermination of trace amounts of Mo(VI) ions. This method is based on contr olled adsorptive preconcentration of molybdenum species on the hanging merc ury drop electrode (HMDE) using mixtures of nitrate and phosphate as suppor ting electrolytes. The adsorptive stripping response was evaluated with res pect to preconcentration time, potential and composition of supporting elec trolyte. The method used is cathodic linear sweep stripping voltammetry (CL SSV). The detection limit found was 1 x 10(-8) M using 120 s. as accumulati on time. The precision of the method is satisfactory with relative standard deviation of 1.4% with five replicates at 1 x 10(-6) M Mo(VI). The effect of various surface active substances (SAS) as well as different metal catio ns and anions in synthetic aqueous solutions has been investigated. Also th is method has been applied for the determination of Mo(VI) in environmental samples; e.g., soil, natural water and indoor airborne particulate.