Determination of As in particulate matter using Se as an internal standard by multi-element electrothermal atomic absorption spectrometry†
In this study Se has been evaluated as a potential internal standard for the determination of As in particulate matter using multi-element electrothermal atomic absorption spectrometry. The use of Se reduced matrix interferences improving the recoveries and method precision, especially at concentration levels near the limit of quantification. Moreover, a better linearity was achieved. The detection limits with and without the use of Se were 1.88 μg L−1 or 1.13 ng m−3 and 2.88 μg L−1 or 1.73 ng m−3, respectively. The calculated recoveries ranged from 98.9% to 110% rather than 41.5% to 114% without Se. In both cases, with and without the use of Se, the method uncertainty was calculated based on Monte Carlo analysis. The results showed that the uncertainty reduced at the lower concentration levels, near the limit of quantification, while it increased at the higher ones. The method was applied to determine As in PM10 samples from an industrial area near Athens. The mean annual concentration of As was found to be 5.69 ng m−3, lower than the air quality limit set by the European Council.