Spectrophotometric Determination of Germanium Following Collection on an Organic Solvent-Soluble Membrane Filter as the Complex with Phenylfluorone

A spectrophotometric method is described regarding the determination of germanium. A colored complex of germanium with phenylfluorone was collected on an organic solvent-soluble membrane filter made of cellulose nitrate. The complex, together with the filter, was dissolved into N, N-dimethylformamide (3cm3), and the absorbance of the solution was measured. The obtained calibration curve was linear from 0.05 to 1.0μg of germanium and the molar absorption coefficient was 1.9×105dm3 mol-1 cm-1. The relative standard deviation of the absorbance obtained at 1.0μg of germanium was 0.4% (n=11). The interference of molybdenum(VI) could be eliminated by hydrogen peroxide. The time required for one run was about ten minutes and germanium at 1μg dm-3 levels could be easily determined. This method has been applied to the determination of germanium in samples of hot-spring water.