Fast and feasible sample preparation methods for extraction of trace elements from deposited particulate matter samples

Abstract

In this study, two alternative sample preparation procedures are proposed, using ultrasound and microwave, for rapid, reliable and easy extraction of trace elements from particulate matter samples. The methods (ultrasound-assisted extraction and microwave-assisted extraction) were compared to conventional acid extraction (literature method). The determination of trace elements by flame atomic absorption spectrometry (F AAS) and graphite furnace atomic absorption spectrometry (GF AAS) was investigated. The results of the three methods did not show any significant difference at a confidence level of 95% for all analytes. The two new methods showed good precision (RSD < 10%), accuracy (the recoveries from suspended particulate samples ranged from 83 to 114%) and reduced time required for sample preparation (approximately 10 min) with small volumes of acid. Using diluted aqua regia, the microwave extraction method was then employed to determine Al, As, Cd, Cr, Cu, Fe, Mn, Pb and Zn from deposited particulate matter (DPM) samples from the city of Juiz de Fora, MG, Brazil, from samples collected passively on cellulose acetate filters. Fe, Al, Zn and Mn were the most abundant elements present in the samples, followed by Cu, Pb, Cr, As and Cd.