Determination of trace gallium by derivative adsorption chronopotentiometry

A sensitive 2nd-order derivative adsorption chronopotentiometric method was developed to determine ultratrace amounts of gallium(III) using a new type of derivative circuitry. A reduction peak of the Ga(III)-morin complex at − 1.01 V could be observed in the 2nd-order derivative chronopotentiogram. The detection limit is as low as 6.0 × 10−11 mol/1. The influence of KH2PO4 on the signal of the reduction of Ga(III)-morin complex was studied and the optimum conditions were selected. The method was used for the determination of ultratrace Ga(III) in KH2PO4 crystals (KDP) and its saturated liquor with satisfactory result.