Determination of traces of gallium based on stripping voltammetry with adsorptive accumulation

Trace levels of gallium can be quantified by linear-sweep voltammetry after absorptive preconcentration of the gallium/solochrome violet RS chelate on the hanging mercury-drop electrode. The interfacial and redox behaviors are evaluated by cyclic voltammetry. The adsorbed chelate yields two distinct reduction peaks that can be utilized to quantify gallijm. The effects of preconcentration time and potential, dye concentration, bulk concentration of gallium, and other variables on the chelate peaks are investigated. For a 2-min preconcentration time, the detection limit is 0.08 μg l^?1. With preconcentration for 60 s, calibration plots are linear for the range 0–16 μg ml^?1 gallium. Possible interferences by other trace metals and surface-active organic materials are investigated. Gallium added to samples of sea and rain water was quantified readily.