Determination of antimony in airborne particulate matter collected on filters using direct solid sampling and high-resolution continuum source graphite furnace atomic absorption spectrometry

Abstract

A method has been developed for the determination of antimony in airborne particulate matter collected on glass fiber filters using direct solid sampling and high-resolution continuum source graphite furnace atomic absorption spectrometry. The certified reference material, BCR 176 (City Waste Incineration Ash) has been analyzed for validation purposes; no statistically significant difference has been found between the certified and the determined value for antimony based on a Student t-test at a 95% confidence level. The secondary antimony absorption line at 212.739 nm, which is about a factor of 20 less sensitive than the primary resonance line, has been used in order to adapt the sensitivity of the method to the antimony concentration in the samples. 400 μg of ruthenium, thermally deposited on the solid sampling platform has been used as permanent modifier. The characteristic mass at this line was found to be m₀ = 0.7 ng Sb. The limit of detection (3σ), based on ten atomizations of an unused filter was found to be 15 μg g⁻¹, corresponding to 40 ng m⁻³ for a typical air volume of 1440 m³. The limits of quantification, based on the same measurements were 50 μg g⁻¹ and 128 ng m⁻³, respectively. The repeatability of the measurements has been between 4% and 9% (n = 5). The antimony concentration found in filter samples varied between <15 μg g⁻¹and 342 ± 16 μg g⁻¹, corresponding to <40 ng m⁻³ and 1820 ± 90 ng m⁻³, respectively. Direct solid sample analysis and detection by high-resolution continuum source graphite furnace atomic absorption spectrometry proved to be a simple, fast and reliable alternative for the determination of Sb in airborne particulate matter. An attempt to transfer the method to conventional line source equipment has been without success because of spectral interference and the weak emission of the secondary line from a hollow cathode lamp.