Mass closure on the chemical species in size-segregated atmospheric aerosol collected in an urban area of the Po Valley, Italy

Abstract

Abstract.A complete size segregated chemical characterisation was carried out for aerosol samples collected in the urban area of Bologna over a period of one year, using five-stage low pressure Berner impactors. An original dualsubstrate technique was adopted to obtain samples suitable for a complete chemical characterisation. Total mass, inorganic, and organic components were analysed as a function of size, and a detailed characterisation of the water soluble organic compounds was also performed by means of a previously developed methodology, based on HPLC separation of organic compounds according to their acid character and functional group analysis by Proton Nuclear Magnetic Resonance. Chemical mass closure of the collected samples was reached to within a few percent on average in the submicron aerosol range, while a higher unknown fraction in the coarse aerosol range was attributed to soil-derived species not analysed in this experiment. Comparison of the functional group analysis results with model results simulating water soluble organic compound production by gas-to-particle conversion of anthropogenic VOCs showed that this pathway provides a minor contribution to the organic composition of the aerosol samples in the urban area of Bologna.

Spatial and Temporal Variation of Chemical Composition and Mass Closure of Ambient PM10 in Tianjin, China

“…This is consistent with the results of Lazaridis et al (2002), Matta et al (2003) and Bi et al (2007), which determined that increased coal combustion for domestic heating and frequent thermal inversions during winter lead to the higher PM 10 level.…”

“…The chemical composition of PM may vary largely depending on PM sources (because of a large number of sources in urban areas), and can reflect differences in source contributions. Thus, efforts have been made over years to elucidate the chemical composition of PM, and to achieve mass closure on the chemical species for the whole mass of PM collected (Matta et al, 2003). The spatial and temporal variation of PM chemical composition greatly depends on factors such as emission/transformation rate, distance of sources, physical conditions of the medium where they are introduced (Perrino et al, 2010;Singh et al, 2012;Saitanis et al, 2013) and meteorological conditions (e.g., mixing depth of the atmosphere, rainfall, wind speed and prevailing wind direction).…”

Comprehensive characterization of humic-like substances in smoke PM<sub>2.5</sub> emitted from the combustion of biomass materials and fossil fuels

“…The relatively few and/or weak sharp peaks in the 1 H NMR spectra of atmospheric HULIS may be the result of low molecular weight organic compounds that have been removed by oxidation or transformed to HULIS. Among these sharp signals, a limited number of resonances could be attributed to specific organic species by comparison with previous studies (Decesari et al, 2000(Decesari et al, , 2001Suzuki et al, 2001;Matta et al, 2003;Cavalli et al, 2006;Chalbot et al, 2014Chalbot et al, , 2016Lopes et al, 2015). These sharp signals included low molecular weight formate (δ8.44 ppm), terephthalic acid (δ8.01 and 8.12 ppm), phthalic acid (δ7.45-7.47 and 7.58 ppm), glucose (δ3.88-3.91 and 3.81-3.85 ppm), fructose (δ3.79-3.84 ppm), trimethylamine (δ2.71 and 2.89 ppm), dimethylamine (δ2.72 ppm), and monomethylamine (δ2.55 ppm).…”

Simulating the global atmospheric black carbon cycle: a revisit to the contribution of aircraft emissions

“…It should be addressed whether the measurements could be biassed due to the lower detection particle size limit of 0.15 µm. Observations performed by Neusüß et al (2000aNeusüß et al ( ,b, 2002 and Matta et al (2003) under a variety of conditions indicate that the BC mass contained in particles smaller than 0.15 µm mostly is small. The contribution of these particles to total BC was generally below 30% during the measurements.…”