Facultade de Fisioterapia

Headspace single-drop microextraction with in situ stibine generation for the determination of Sb(III) and total Sb by electrothermal-atomic absorption spectrometry

Authors: Francisco Pena-Pereira, Isela Lavilla, Carlos Bendicho

Journal: Microchimica Acta, 164: 77-83, 01/2009

DOI: https://doi.org/10.1007/s00604-008-0036-z


Abstract

A headspace-single drop microextraction method combined with electrothermal atomic absorption spectrometry (ETAAS) is developed for the extraction and preconcentration of antimony(III) and total antimony into a Pd(II)-containing aqueous drop after hydride generation. Experimental variables such as hydrochloric acid and sodium tetrahydroborate concentrations, sample volume, Pd(II) concentration in the acceptor phase and microextraction time were optimized. A 26-2IV factorial fractional design was initially used for screening the effect of the variables, followed by an univariate approach. The method showed a great freedom from interferences caused by hydride-forming elements and transition metals. The detection limit of Sb(III) was 25 pg mL−1. A preconcentration factor of 176 is achieved in 3 min. The repeatability, expressed as relative standard deviation, was 4.7%. The method was validated against two certified reference materials (NWRI-TM 27.2 and NIST 2711) and applied to the determination of Sb(III) and total Sb in waters.