Speciation analysis of inorganic antimony in airborne particulate matter employing slurry sampling and HG QT AAS

Abstract

The present paper proposes an analytical procedure for speciation analysis of inorganic antimony in airborne particulate matter using slurry sampling and hydride generation atomic absorption spectrometry (HG QT AAS). During the antimony determination, a quartz T tube cell was heated to approximately 900 °C using air–acetylene flame. The optimization step was performed by employing full two-level factorial and Box–Behnken designs involving the following factors: flow rate and concentration of sodium tetrahydroborate and hydrochloric acid concentration, having as chemometric response absorbance. Using the optimized conditions, the method employing slurry sampling allows for the determination of total Sb and Sb(III) with limits of quantification of 0.3 and 0.2 μg L⁻¹, respectively. The precision, expressed as a relative standard deviation (%RSD), was always lower than 6.2%. The accuracy was confirmed by analysis of a certified reference material of atmospheric particulate matter urban dust furnished by National Institute of Standards & Technology. This method was used to determine total antimony and antimony(III) in four particulate matter samples collected in Bananeira Village, Bahia State, Brazil. In these samples, total antimony concentrations varied from 4.32 to 4.60 ng m⁻³, and Sb(III) concentrations varied from 0.33 to 0.67 ng m⁻³.