Determination of germanium, vanadium, and titanium by carbon furnace atomic absorption spectrometry

Acids strongly influence the Ge, V and Ti absorption signal. Nitric acid increased the signal of Ge but decreased the signal of V and Ti. Sulfuric acid decreased the signal of all examined elements. Phosphoric acid decreased the signal of Ge but enhanced the signal of V and Ti. Hydrochloric acid depressed the signal of Ge and V but increased the signal of Ti. Ammonium salts of these acids on the whole changed the signals of investigated elements like acids, but there are several exceptions (ammonium sulfate for Ge, V and Ti, ammonium phosphate for Ge and V; ammonium perchlorate for Ti). The working range of all examined elements was between 0.1-0.5 ppm. The calculation graphs were linear up to a concentration of # < approx 0.4 ppm. The sensitivities (1% absorption) were: 0.0015 ppm for Ge, 0.03 ppm for V and 0.08 ppm for Ti. The addition of 2-pyridylphosphinic acid reduced the interference of sulfuric acid on Ge and enhanced the signal of V in the presence of nitric acid but decreased the signal of Ti.39 refs.--AA