Determination and biokinetics of germanium in mouse tissues by atomic absorption spectrometry with electrothermal atomization.

There are few papers on the analysis of Ge in biomaterials. A highly sensitive method is required for such determination of Ge because its concentration is very low. We developed a sensitive analytical method for determining Ge in biomaterials by using 0.05 mol/l Co (NO3)2 media as a matrix modifier with flameless atomic absorption spectrometry. This method was applied to the determination of Ge in mouse tissues, and the biokinetic parameters of Ge in mouse tissues were evaluated using the data of uptake and retention after a single peroral administration of GeO2 solution. Ge was not detectable in the blood or tissues of normal mice. The uptake of Ge into kidney is much larger than that into other tissues after injection of GeO2 solution. The disappearance of Ge from blood and the tissues is very fast. It could hardly be detected in any of the tissues 24 h after injection. The biological half-life of Ge in brain is 6.3 h, but in other tissues--1.2 h (in blood) to 4.5 h (in pancreas)--it is shorter than in brain. By the fact that Ge is rapidly excreted from all tissues, it can be understood that Ge is not detected in normal mouse tissues and its toxicity is weaker than that of other metals.