Abstract
A simple and rapid method for the spectrophotometric determination of germanium in microgram amount with phenylfluorone in organic phase after the extraction with carbon tetrachloride is described. The complex formed in organic phase has an absorption maximum at 508 mμ, and its molar absorptivity is estimated to be 16×104. A sample solution (containing Ge<8 μg) is transfered to a 50-ml separatory funnel and the acidity is adjusted to 9 N with hydrochloric acid and to approximately 20 ml in total volume. Ten ml of carbon tetrachloride is added, shaken for about 2 min., and then 5 ml of the organic layer is transfered to a 10-ml volumetric flask which contains 3 ml of ethanol (99.5%) and 1 ml of 0.05% phenylfluorone-ethanol solution (0.05 N in HCl). It is diluted with ethanol. Five min. later, absorbance is measured at 508 mμ against a blank. The color is stable for at least 10 hrs. It obeys the Beer's law in the range of 00.4 μg Ge/ml. The coefficient of variation was found to be 0.97% at 0.25 μg Ge/ml. An examination of the eff ct by diverse ions showed the method to be highly selective.
