Abstract
Atmospheric particulate matter samples (PM10) have been collected on quartz and Teflon filters, for 12 days from 16th to 28th of March 2006 on the 4th floor of the University of Science and Technology in Taiyuan, China. The samples were analysed for the metal elements aluminium (Al), iron (Fe), calcium (Ca), magnesium (Mg), sodium (Na), silicon (Si), titanium (Ti) and zinc (Zn), with inductively coupled plasma atomic emission spectrometry (ICP-AES); copper (Cu), lead (Pb), manganese (Mn), arsenic (As), cadmium (Cd), cobalt (Co), nickel (Ni), antimony (Sb), selenium (Se) and vanadium (V), with inductively coupled plasma mass spectrometry (ICP-MS); ammonium (NH4+), sulphate (SO42-) and nitrate (NO3-), with ion chromatography (IC) and organic and elemental carbon (OC, EC) with a thermal/optical carbon analyser.
The average aerosol composition was determined and the mass closure yielded (60.8±12.5)% crustal material, (11.4±3.9)% OC, (5.5±2.0)% EC, (4.4±1.4)% SO42-, (1.2±0.6)% NO3-, (1.6±0.8)% NH4+ and (15.1±21.2)% unknown. The dominating ammonium specie, averaged over the 12 days of sampling, was ammonium sulphate (NH4)2SO4. Aerosol-crust enrichment factors and correlation coefficients were applied to identify potential sources of anthropogenic pollutants, and the results pointed towards coal-burning activities as the dominating source. The mean bulk PM10 atmospheric mass concentration was (385±105)ìg/m³, significantly exceeding all Chinese air quality guidelines. Nevertheless, a trend towards improved air quality was noticed by comparing the results with a previous study from the same location and almost same time of year.
Additionally, two more studies were carried out with samples provided by the Norwegian Institute of Air Research (NILU). A new temperature protocol for the thermal/optical carbon analysis was tested and the results were compared to an existing protocol, with surprisingly good agreement. Further, backup filters from sampling of different size fractions (PM10, PM2.5, PM1.0) were analysed with the thermal/optical carbon analyser and the found amounts of vapour phase OC were compared among the various size fractions with satisfactory results.