The Influence of Oceanic Air Masses on Concentration of Major Ions and Trace Metals in PM2.5 Fraction at a Coastal European Suburban Site

A comprehensive chemical characterisation of the ionic and metallic composition of PM2.5 fraction of suburban aerosol collected with high‐volume aerosol samplers at a coastal suburban site of northwest Atlantic European is studied over a 1.5-year period (from March 2011 to August 2012). The monthly mean PM2.5 mass concentrations (after gravimetric measurement) ranged from 13 to 26 μg m−3. Eighteen samples, which provide information pertaining to the monthly variation in chemistry, were analyzed. Trace metals (Al, As, Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) were analysed in PM2.5 fraction after acid extraction (total metallic concentration) and after sonication-assisted water extraction (aqueous soluble fraction). Major inorganic ions (Cl−, NO3 −, SO4 2−, Na+, K+, Ca2+, Mg2+, NH4 + and C2O4 2−) were also analysed in the aqueous fraction of PM2.5. Trace metal extractability in water was in the range 50–67 % with exception of Al (∼2 %), Fe (∼4 %) and Cr (∼18 %). After univariate, cluster (CA) and principal component (PCA) analyses and air mass backward trajectory analysis, marine, crustal and anthropogenic (including road traffic) sources were found for the inorganic composition of PM2.5. Results also suggest a great influence of cleaner Atlantic air masses and ubiquitous sources for K+, Mg2+, Fe, Ni and V.