Effect of Acid on Determination of Germanium in Foods by Microwave Digestion-Hydride Generation Atomic Fluorescence Spectrometry

The determination of germanium in foods was conducted by microwave digestion and hydride generation atomic fluorescence spectrometry. The effects of the volume fraction of phosphoric acid as the carrier liquid and the residual nitric acid in the digestion process on the measurement results were studied. When the volume fraction of phosphoric acid varied from 5% to 30%, the slope of the standard curve ascended, so that 10%~20% phosphoric acid is suitable as the carrier liquid for the determination of germanium by atomic fluorescence spectrometry. When the volume fraction of nitric acid exceeded 1%, the fluorescence intensity of germanium decreased seriously. Using the improved method of determination, a recovery experiment in garlic samples was implemented. A determination of germanium in Ge-132 capsule was also implemented to verify the digestion effect to organic germanium. The recovery of the garlic test was 109.7%, and the measured value of the Ge-132 capsule was 81.4% of the label identification value. Both results were fairly satisfactory. The method of determination is reliable.