抄録
In the medium of dilute sulfuric acid germanium(IV)-trihydroxybenzoic acid complex produced an adsorptive current at-0.62V(vs. SCE), which could produce a parallel catalytic current in the presence of vanadium(IV). After adding EDTA, this current could be further increased.The sensitivity was raised to about 1200-times higher than that in the absence of vanadium(IV) and EDTA in above-mentioned medium. The chemical reaction rate constant(k1) was calculated to be 14.4×106L/mol s-1. The peak height(second derivative)(ip") was proportional to the concentration of germanium(IV)(CGe(IV)) in the range of 0.04-20μg/L Ge(IV). The correlation coefficient (r) and detection limit (DL) were 0.9996 and 5×10-11mol/L Ge(IV) respectively. The composition of complex, the apparent stability constant (k) of this complex, the current property, the mechanism of the electrode reaction and the mechanism of the electrochemical response enhanced by EDTA were investigated in detail. Possible interferences were evaluated. The proposed method was applied to determine the trace germanium in alloys with satisfactory results.
