酸对微波消解-氢化物发生原子荧光光谱法测定食品中锗的影响

以微波消解为前处理手段，采用氢化物发生原子荧光谱法测定食品中的锗，研究了作为载液的磷酸体积分数和消解过程中残留硝酸对测定结果的影响. 磷酸体积分数从5%增加至30%时，标准曲线斜率缓慢上升. 认为10%~20%体积分数磷酸适宜作为原子荧光光谱法测锗的载液. 硝酸在样品中体积分数超过1%后，锗的荧光信号严重减弱. 优化条件后对市售大蒜样品进行加标试验. 为进一步确定对有机锗的消解效果，对某批次锗-132胶囊进行测定. 大蒜加标试验回收率为109.7%，胶囊测定值为标签标识值的81.4%. 两次试验结果均较为满意，说明方法具有可靠性.

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.