Determination of inorganic elemental concentrations in PM_2.5 by ICP-MS and the analysis of pollution characteristics

The concentrations of 23 inorganic elements in PM_2.5 were determined directly and simultaneously by inductively coupled plasma mass spectrometry (ICP-MS) combined with microwave digestion. The working parameters and conditions of the digestion and ICP-MS were optimized and selected. The detection limits ranged from 0.01 to 10.00 ng/mL and the quantitative detection limits were at the range of 0.04-40.00 ng/mL. PM_2.5 membrane filter samples, collected in three monitoring sites of Tangshan City from October of 2017 to January of 2018, were measured by the method. and the results of the analytical data were shown as follows. The concentration of Si was 2.30 μg/m³, which was the highest value among the measured crustal elements. Most elements had higher concentrations during the before-heating period than during the heating period. The concentration of Zn was 0.48 μg/m ³, which was the highest value among the heavy metals, and the concentrations of these heavy metals were mostly higher in November and December during this observation campaign. The measured elemental concentrations were mostly comparable to other literature data, which showed that this method was suitable for inorganic multi-element analysis of ambient atmospheric PM_2.5.