Chemical characterization of PM10 fractions of urban aerosol

The goal of this investigation was to give an overview about the trace metal and total organic/inorganic carbon (TOC/TIC), water-soluble carbon (WSOC) and polyaromatic hydrocarbons (PAH) concentrations in the PM10 aerosol fraction in Budapest and to monitor monthly changes during the sampling period, whether there is a tendency in the seasonal change of the concentrations. The sampling took place in Budapest, Hungary between September 2004 and August 2007 in an area with high traffic density. For the sampling, a high-volume aerosol sampler equipped with a PM10 head was used. The samples were taken onto quartz fiber filters. Each month, one sample was collected. Sampling time was 96 h, the air intake was 30 m³/h, resulting in 2880 m³ sampled air volume.To measure the metal concentrations two types of sample preparation were used: microwave assisted aqua regia extraction and water extraction by sonication. In both cases, the solutions were analyzed by using a sector field inductively coupled plasma mass spectrometer (SF-ICP-MS). The following 23 elements were investigated: V, Cd, Zn, Cu, Ni, Sb, Sn, Cr, Pt, Pb, Te, Tl, U, Mn, Fe, Co, Ga, Rb, Sr, Mo, Ag, Bi, Li. Comparing the data obtained from the aqua regia extraction to some other cities, the measured trace elements were found in moderate concentration. In the water extract, a significant part of zinc and thallium was found. During the sampling period, no proof of seasonal change in trace element concentrations was found. Trace metal and total organic/inorganic carbon concentrations in Budapest were similar to the concentration data measured in other cities with exception of Mn, Ga, Rb, Cd which are present in higher concentration in Budapest. The TOC content in the PM10 fraction amounted to 30-50%, and its value was the highest during the winter period due to the heating.The yearly average concentration of polyaromatic hydrocarbons was almost constant over the investigated period, but its seasonal change is more than one order of magnitude.