Preconcentration of ultra-trace germanium in water samples with nano-sized TiO₂colloid and determination by GFAAS with colloid sampling

Abstract

A method for preconcentration and determination of ultra-trace germanium is presented in this work. Germanium (Ge(IV) in this work) in the water samples was preconcentrated by applying nano-sized TiO 2 colloid as adsorbent. When the pH values of solution were 6.0-8.0, the adsorption efficiency of nano-sized TiO 2 colloid for germanium reached 97.0 $ 99.0% in a short time. After centrifugation, the sediment which contained the concentrated Ge(IV) was inverted to colloid by adding HNO 3 of certain concentration. Ge(IV) in colloid was determined by graphite furnace atomic absorption spectrometry (GFAAS). In this study, germanium was approximately 20 times concentrated and a low detection limit (3s) of 43 ng L À1 was achieved. As the adsorbed Ge(IV) in colloid could be directly determined by means of GFAAS, desorption process was not needed, which simplified the process. This method was applied for the determination of ultra-trace germanium in water samples and satisfactory results were obtained.

Speciation analysis of antimony in water samples via combined nano-sized TiO2 colloid Preconcentration and AFS analysis

“…[12][13][14][15][16] Compared with nanosized TiO 2 powder, the colloids possess the advantage of easily changing from the solid phase to the colloid phase aer adsorption and centrifugation. The required input of colloids is low because of their high adsorption capacity, and an autosampler can be used because the viscosity of the resulting solution is close to that of the aqueous solution.…”

ONE-STEP AND CONTROLLABLE SELF-ASSEMBLY OF Au/TiO2/CARBON SPHERES TERNARY NANOCOMPOSITES WITH A NANOPARTICLE MONOSHELL WALL

“…It is reported that TiO 2 NPs colloid could preconcentrate the ultratrace germanium in water samples because of its great adsorption property. 6 Basically, the adsorption property of a photocatalyst would actually in°uence the enablement and conduct of the photocatalysis reaction. Thus, it is valuable to prepare well dispersed and stable TiO 2 colloid.…”

Preconcentration of Germanium(IV) on Styrene-Maleic Anhydride Copolymer Modified with Aminobenzoic Acids and Its Spectrophotometric Determination with Bis(2,3,4-trihydroxyphenylazo)benzidine

“…The tolerance limits (w/w) less than ±3% change in the per centage uptake of germanium ions was taken as being free from the interference. The experimental results indicated that alkaline and earth-alkaline metals, Zn(II), Cd(II), Mn(II), Ni(II), Co(II), Al(III), Ga(III), In(III), Bi(III), Ti(IV), Zr(IV), Hf(IV), Sn(IV) and Pb(IV) as well as anions had no significant effect on the separation and determination of Ge(IV) under the recommended conditions, and the most serious interference arose from Cu(II) and Fe(III) ( [2,3,27,30]. The now described results also clearly indicate that the proposed sorbents can be applied for the column preconcentration/enrichment of germanium in the presence of high background matrix.…”

“…It is rather rare and is found in nature dispersed in ore deposits or being dissolved in trace quanties, mainly as soluble germanate anions and methylgermanium species [2,3]. The concentration of germanium and its easy determination on the trace and ultra-trace levels is of importance and has been pursued for many years [1,4].…”

“…The preconcentration of germanium by sorption offers several advantages over other methods of concentration (e.g., liquid-liquid extraction), such as experimental convenience, low cost and usage of less toxic materials. To date, there are a few works related to the preconcentration of germanium on a solid substrate, for instance on Kelex-100 [29], nanometer sized TiO 2 /SiO 2 [3], TiO 2 [2,19], active carbon [32], cellulose [10], chitosan chelating resin [5,9], Sephadex gel [6], anionic resin (IRA-900) [31], goethite [33] and mercaptomodified silica gel [7]. However, most of the described sorbents have one or more of the following disadvantages: relatively low selectivity [2,19,27], low sorption capacity [32], low rate of sorption [5,32,33] or high cost of sorbent [2,3,30].…”