Sensitization of stibine generation: antimony determination in environmental samples by atomic fluorescence spectrometry

Abstract

This paper reports an improvement in the efficiency and selectivity of stibine generation and therefore an improvement in the analytical characteristics for antimony determination in environmental matrices by atomic fluorescence. The sensitized method is achieved by generating the stibine at 70 °C and using additional hydrogen flow to sustain the atomization flame, which makes it possible to reduce the acid and borohydride concentration and therefore to economize the process and reduce the inherent pollution risks due to the high concentrations used. Furthermore, a new phase separator in which temperature is controlled and dead time significantly reduced has been designed and incorporated in the hydride generation system. Selectivity is increased by working in an organized medium, Triton X-100 being the surfactant chosen as the most appropriate. Under the optimized conditions, a limit of detection of 0.3 mg l−1 of Sb was achieved, with a precision of 1.4% for 8 mg l−1, and the calibration graph was linear from 0.3 to 2.7×103 mg l−1. The sensitized method performed satisfactorily when evaluated by the determination of Sb in standard reference material (SRM 1648) of atmospheric urban particulate matter and by recovery studies in sea-water, tap water and in air samples collected on silica filters. The recovery in the enriched samples was 99±1% in all cases. The proposed method was successfully applied to the determination of Sb in samples of Bilbao urban air, being 13.2±0.3 ng m−3, the antimony concentration found.

Methodologies for determination of antimony in terrestrial environmental samples

“…56,81±83 These trapping systems enable enhanced preconcentration of the analyte prior to detection and subsequent detection limits are reported around 0.3 pg mL 21 . 56 Additional in-line techniques include hydride generation coupled with atomic ¯uorescence detection (HG-AFS) 53,84 and GC with ¯uorine induced chemiluminescence and mass spectrometric detection. 85 The detection limits for these less common techniques are generally acceptable, although the extent of the qualitative data are often limited, as only a single aqueous species is selectively determined.…”

Determination of antimony in soils and vegetables by hydride generation atomic fluorescence spectrometry and electrothermal atomic absorption spectrometry. Optimization and comparison of both analytical techniques

“…However, there are few applications of this technique to determine total antimony in solid environmental samples; it has been mainly applied to quantify antimony in liquid samples such as tap water, seawater and environmental air samples. 22 The aim of this study was the development and optimization of analytical methodologies based on digestion procedures and the subsequent precise, reliable, and accurate determination of antimony in soils and vegetable samples using two sensitive atomic spectrometry techniques, based on different chemical± physical principles: electrothermal atomic absorption spectrometry (ET-AAS) and atomic ¯uorescence spectrometry coupled to stibine generation (HG-AFS). To reach this goal the different experimental parameters of each technique that in¯uence the analytical signal obtained in the antimony determination were optimized, using synthetic solutions of Sb(III) and Sb(V), and solutions obtained after total digestion of natural soils and plant samples.…”

The effect of the presence of volatile organoselenium compounds on the determination of inorganic selenium by hydride generation

“…Afterwards, they were purged with 300 mL min -1 argon and led to the detector. A new gas liquid separator designed in our laboratory and described in a previous paper [30], was used.…”