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Ruger C.P.,University of Rostock | Sklorz M.,University of Rostock | Sklorz M.,Helmholtz Center Munich | Schwemer T.,University of Rostock | And 4 more authors.
Analytical and Bioanalytical Chemistry | Year: 2015

In this study, positive-mode laser desorption-ionisation ultra-high-resolution mass spectrometry (LDI-FT-ICR-MS) was applied to study combustion aerosol samples obtained from a ship diesel engine as well as the feed fuel, used to operate the engine. Furthermore, particulate matter was sampled from the exhaust tube using an impactor and analysed directly from the impaction foil without sample treatment. From the high percentage of shared sum formula as well as similarities in the chemical spread of aerosol and heavy fuel oil, results indicate that the primary aerosol mainly consists of survived, unburned species from the feed fuel. The effect of pyrosynthesis could be observed and was slightly more pronounced for the CH-class compared to other compound classes, but in summary not dominant. Alkylation pattern as well as the aromaticity distribution, using the double bond equivalent, revealed a shift towards lower alkylation state for the aerosol. The alkylation pattern of the most dominant series revealed a higher correlation between different aerosol samples than between aerosol and feed samples. This was confirmed by cluster analysis. Overall, this study shows that LDI-FT-ICR-MS can be successfully applied for the analysis of combustion aerosol at the molecular level and that sum formula information can be used to identify chemical differences between aerosol and fuel as well as between different size fractions of the particulate matter. © 2015 Springer-Verlag.

Leskinen J.,University of Eastern Finland | Ihalainen M.,University of Eastern Finland | Torvela T.,University of Eastern Finland | Kortelainen M.,University of Eastern Finland | And 17 more authors.
Environmental Science and Technology | Year: 2014

The effective density of fine particles emitted from small-scale wood combustion of various fuels were determined with a system consisting of an aerosol particle mass analyzer and a scanning mobility particle sizer (APM-SMPS). A novel sampling chamber was combined to the system to enable measurements of highly fluctuating combustion processes. In addition, mass-mobility exponents (relates mass and mobility size) were determined from the density data to describe the shape of the particles. Particle size, type of fuel, combustion phase, and combustion conditions were found to have an effect on the effective density and the particle shape. For example, steady combustion phase produced agglomerates with effective density of roughly 1 g cm-3 for small particles, decreasing to 0.25 g cm-3 for 400 nm particles. The effective density was higher for particles emitted from glowing embers phase (ca. 1-2 g cm-3), and a clear size dependency was not observed as the particles were nearly spherical in shape. This study shows that a single value cannot be used for the effective density of particles emitted from wood combustion. © 2014 American Chemical Society.

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