纳米二氧化钛胶体分离富集-氢化物原子荧光光谱法测定水中超痕量锗

提出了用纳米TiO2胶体富集,氢化物原子荧光光谱法测定水样中超痕量锗的新方法。当溶液的pH为6.0～8.0时,纳米TiO2胶体对Ge((Ⅳ)吸附率为97.0～99.0%,并且吸附速度快。利用纳米TiO2胶体良好的吸附性能对水样中超痕量Ge((Ⅳ)进行富集,离心后,弃去上清液,用少量盐酸将富集了Ge((Ⅳ)的沉积物(纳米二氧化钛)转化成胶体,用氢化物原子荧光光谱法直接测定胶体中的锗。该法检出限(3σ)低(0.060μg.L-1),精密度好(相对标准偏差(RSD)为2.0%),简单、快速(省去了繁琐的过滤和脱附过程),用于实际水样中超痕量锗的测定,结果满意。

Preconcentration of ultra-trace germanium in water samples with nano-sized TiO2 colloid and determination by HGAFS with colloid sampling

A novel method for preconcentration of ultra-trace germanium and determination by hydride generation atomic fluorescence spectrometry (HGAFS) was presented in this work. When the pH values of solution were 6.0-8.0, the adsorption efficiency of nano-sized TiO2 colloid for germanium was 97.0%-99.0% in a short time. Nano-sized TiO2 colloid was used to concentrate the ultra-trace germanium in water sample due to its high absorption capacity. After centrifugation, the supernatant fluid was removed. The sediment which contained the concentrated Ge(IV) was inverted to colloid by adding HCl of certain concentration. Ge(IV) in colloid was directly determined by HGAFS. The proposed method possesses low detection limit (3sigma) (0.060 microg x L(-1)) and good precision (the relative standard deviation (RSD) is 2.0%, n=6). The method is was also quite simple and time saving (without any filtration and desorption process). Satisfactory results were obtained when applying this method to the determination of ultra-trace germanium in water samples.