Germanium (Ge) is the third element in Group IVA in the periodic table. It has an atomic number of 32, an atomic weight of 72.59, and valences of 2 and 4. The average abundance of Ge in the earth’s crust is 1.5 ppm; in streams it is 0.03 to 0.1 μg/L; and in groundwaters it is <0.1 mg/L. Germanium is found in germanite, in certain zinc ores, and in elevated levels in certain hot spring waters. Germanium alloys are used in transistors, gold alloys, phosphors, and semiconducting devices.
Germanium is present in natural waters in the tetravalent state, and its distribution in natural waters probably is controlled by adsorption on clay mineral surfaces. It is nonessential for plants and animals.
Perform analyses by the electrothermal atomic absorption method (Section 3113 B). The inductively coupled plasma/mass spectrometric method (Section 3125) also may be applied successfully in most cases (with lower detection levels), even though germanium is not specifically listed as an analyte in the method.