Determination of ultra trace Uranium in Lichen by Adsorptive-Cathodic Stripping Voltammetric Technique

摘要

Cathodic Stripping Voltammetric (DPAdCSV) method was optimized and validated for the determination of uranium (U) in lichen using choranilic acid (CAA) as complexing agent. The complex can be used for a selective and ultra-trace determination of 'U' by adsorptive cathodic stripping voltammetry (AdCSV) using a hanging mercury drop electrode (HMDE) as working electrode. The method was validated by generating data on parameters such as linearity, precision, accuracy, sensitivity, method detection limit (MDL), quantitation limit (LQ) and selectivity. Experiments were also carried out to study the influence of effective parameters such as pH, concentration of CAA, deposition potential, deposition time and sweep rate on the sensitivity and selectivity of method. The validation data demonstrate that DPAdCSV is a viable alternative technique to current methods which enables quantitative analysis of uranium in environmental samples like lichens with MDL and LQ of 0.35 μg L-1 and of 1.0 μg L-1 respectively. The case study carried out at Mumbai suburban, India revealed that, level of uranium in lichen at this area varies from 36.2 to 62.8 μg Kg-1.