Adsorptive complex catalytic polarographic determination of germanium in soils and vegetables

The very sensitive adsorptive complex catalytic wave of Ge(IV)-catechol-NaBrO3 with acetic acid—sodium acetate as supporting electrolyte in linear-sweep polarography has been successfully applied to the determination of germanium in vegetables and soils. The optimum experimental conditions are: 0.07 M acetic acid—sodium acetate buffer of pH 4.6, 1.5 × 10−3 M catechol and 0.1 M NaBrO3. The detection limit of Ge(IV) is 1.0 × 10−9 M and the linear range is 1.0 × 10−9 −7.0 × 10−6 M. Different acid digestion procedures were compared, and a HNO3-HClO4-HF digestion method for the soil sample and a HNO3-HClO4-H2SO4 digestion method for the vegetable sample were adopted. The experiments show that the polarographic wave behaves as an adsorptive complex wave and also as a parallel catalytic wave.