FACTORS INFLUENCING THE ATOMIZATION OF GERMANIUM IN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

Factors that influence the atomization of Ge in the graphite furnace have been studied. These include the presence of an oxidizing agent or an alkali and the modification of the graphite tube surface. The graphite furnace atomic absorption spectrometry determination of Ge suffers from low sensitivity and poor reproducibility because GeO2 is reduced to volatile GeO when heated in the presence of carbon, which results in premature loss of Ge. This problem can be overcome by suppressing the reduction of GeO2 during ashing and by atomizing the germanium oxides as they are vaporizing. Reduction of GeO2 can be suppressed by the addition of oxidizing agents, such as HClO4 or NHO3, or alkali to the sample solution or by the use of a W-coated or Zr-coated graphite tube.