R Miravet | PubMed Health

PubMed2005

Antimony speciation in terrestrial plants. Comparative studies on extraction methods.

A suitable method for the extraction of antimony species from plant materials prior to IC-HG-AFS analysis is presented. The extraction efficiency with different extraction systems using various aqueous and aqueous/solvent mixtures was initially evaluated by analysing the Virginia Tobacco Leaves Certified Reference Material. The concentration of antimony extracted was compared with the total antimony content in the plant material measured by HG-AFS after focused microwave-acidic digestion using HNO3 and H2O2. The proposed extraction procedures were applied to antimony speciation in several plants from a natural terrestrial environment impacted by mining activities. End-over-end agitation (4 h) followed by sonication (1 h) extraction using 0.1 mol l(-1) citric acid was found to provide the best extraction efficiency while also giving reliable speciation information. Both inorganic and methylantimony species were found in the extractable portion of some terrestrial plants.

Antimony↗

PubMed2004

New considerations about the separation and quantification of antimony species by ion chromatography-hydride generation atomic fluorescence spectrometry.

A new method for the speciation of inorganic [Sb(III) and Sb(V)] and organic (Me3SbCl2) antimony species by using a polystyrene-divinylbenzene-based anion-exchange HPLC column (Hamilton PRP-X100) coupled to hydride generation atomic fluorescence spectrometry (HG-AFS) is presented. Several mobile phases were tested for the baseline separation of these three antimony species, investigating in detail experimental parameters such as concentration and pH. The best efficiency and resolution was achieved by using a gradient elution between diammonium tartrate 250 mmol l(-1) pH 5.5 (A) and KOH 20 mmol l(-1) pH 12 (B). The gradient programme used was 100% B for 1.5 min, decreasing to 0% B in 0.1 min and maintained the elution with 100% A for 5.5 min. Analysis time was less than 7 min. Equilibration of the column with the complexing mobile phase was found to be critical in order to avoid Sb(III) double peak formation. Dilution in diammonium tartrate medium was necessary in order to avoid Sb(III) oxidation at microg l(-1) concentration level. Detection limits of 0.06 microg l(-1) for Sb(V), 0.09 microg l(-1) for Me3SbCl2 and 0.04 microg l(-1) for Sb(III) as well as repeatability and reproducibility better than 5% R.S.D. (n = 10) and 9% R.S.D. (n = 30) (for 1 and 5 microg l(-1) of Sb(V) and Sb(III) and 5 and 10 microg l(-1) of Me3SbCl2) were obtained. Accuracy and recovery studies were carried out by analysing one river freshwater sample and two water certified reference materials. The proposed methodology can be considered reliable and straightforward for antimony speciation in fresh water samples.

Antimony↗