[Determination of trace beryllium in geological samples by oxygen doped air-acetylene flame atomic absorption spectrometry].

A new method for the determination of trace beryllium in geological samples by oxygen-air-acetylene flame atomic absorption spectrometry is reported in the present paper. The optimum determination conditions were selected. When suitable amounts of 8-hydroxyquinoline are added, the interference effect from the coexisting elements can be minimized and the sensitivity for the determination of beryllium can be increased. The detection limit (k = 3) is 0.006 microg x mL(-1) for beryllium. The method has been applied to the determination of trace beryllium in geological standard samples, and the results are in good agreement with the certified values with a precision of 4.69% RSD( n = 8).

[Study and application of flow injection liquid-liquid extraction non-aqueous media mercury reduction atomic fluorescence spectrometry].

A new method for on-line solvent extraction covalent hydride generation in a non-aqueous media was proposed. Flow injection techniques were used to develop an efficient on-line solvent extraction pre-concentration and pre-separation system. The hydride generation is carried out in an aliquot of metal-complex extraction solution by sodium tetrahydroborate(III) in N,N-dimethyl formamide solution and anhydrons acetic acid. Hg is extracted by KI + HNO3 + (NH2)2CS into TBP and hydride generation by proposed method. A improved u-type gas-liguid separator was used. The working conditions and manifolds scheme of flow injection had been optimized. The method is applied to the determination of mercury in GSD-4 and GSD-6 geological reference materials with good accuracy and precision.

[Determination of zinc in mineral by FAAS after phase separation and extraction].

Non-ion surface active agent can be separated from its solution of water by heating to its cloud point. A new method for the determination of zinc in mineral samples by flame atomic absorption spectrophotometer after phase separation and extraction making use of its cloud point was studied in this paper. The conditions of phase separation and extraction such as using Triton X-100 as phase separation agent, and octanol to drop the cloud point, and the influence of acidity and the number of times for oscillating were discussed. The detection limit was 0.005 microg x mL(-1). This method has been applied to the determination of zinc in ores with satisfactory results.

[Determination of available as (III) and as (V) in soils by flow injection hydride generation atomic fluorescence spectrometry].

A method for the determination of available As (III) and As (V) in soils by flow injection hydride generation atomic fluorescence spectrometry (FI-HG-AFS) was presented. As the concentration of As (III) in extract was determined by HG-AFS in the medium of 0.1 mol.L-1 citric acid solution and the total arsenic was determined after FI on-line reduction of As (V) by L-cysteine, the concentration of As (V) was calculated by the difference. The manifolds for FI on-line reduction of As (V) were designed. The chemical conditions and the operating parameters were optimized. The detection limits (3 sigma) of As (III) and As (V) are 0.11 and 0.07 ng.mL-1, respectively, and the relative standard deviation is 1.43 for 7 determinations of 10 ng.mL-1 As (III) solution. The developed method was applied to the determination of available As (III) and As (V) in real soils and the recovery was 82%-104%.