[Simultaneous determination of germanium and molybdenum in mixtures by complexation with 5'-nitrosalicyfluorone and dual-wavelength standard addition spectrophotometry].

In the presence of hexadecyltrimethylammonium bromide and in a medium of 0.3-0.9mol/L sulfuric acid, germanium (IV) and molybdenum (VI) react with 2,6,7-trihydroxy-9 (2'-hydroxy-5'-nitro) phenylfluorone-3, i.e., 5'-nitrosalicyfluorone, to develop red complexes, respectively. The spectra of the two complexes overlap seriously each other, and the additivity of their absorbances is good in the wavelength range of 490-548nm. So a new method for simultaneous spectrophotometric determination of germanium and molybdenum by dual-wavelegth standard addition method has been investigated in detail. The analytical results of five standard mixtures are more accuracy than those obtained by isobestic-point dual-wavelength method. The method has been applied to the analysis of traditional chinese medicine and mineral water with satisfactory results.