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Evolved Gas Analysis of Ambient and Surrogate Carbonaceous Particles
| Content Provider | Semantic Scholar |
|---|---|
| Author | Karg, Erwin W. Matuschek, Georg Schmid, Otmar Schroeppel, Andreas Schulz, Heiko |
| Copyright Year | 2005 |
| Abstract | Introduction The content of elemental and organic material of carbonaceous particulates (EC/OC) is an important parameter for characterization, especially the OC content is frequently used for correlation with negative health effects. Most methods detect OC by thermally desorbing OC, oxidizing it to CO2 and quantify it based on the measured CO2 concentration (Birch, 1999). Alternatively, one can also use mass spectrometry to chemically characterize the desorbed material for e. g. organic material with higher boiling points, adsorbed gaseous components, low volatile reaction products and disintegrated particulate matter. In this study, the latter approach was employed to analyze the thermally desorbed components from eight types of ambient and laboratory generated particulates for mass as well as organic and inorganic components. Methods Ambient samples of Diesel soot and tunnel dust, commercially available furnace soot, diffusion flame soot and spark generated carbon agglomerates were used (see table). Depending on origin and/or generation process these particles were categorized as either high or low OC samples. Aliquots of one milligram from each sample were exposed to progressively increasing temperatures from ambient temperature to 800 °C at a heating rate of 20 K/ min. The thermally desorbed mass was quantified by thermogravimetry (TG, model TG209, Netzsch, Germany and Vector 22 FTIR, Brucker, Germany) (Raemaekers, 1997). Another aliquot was pyrolyzed and analyzed by gas chromatography and mass spectrometry (pyr/GC-MS, model "Double Shot Pyrolyzer", Frontier Lab, USA and model 5890/5972 GC-MSD, Agilent, Germany) (Ochsenkuhn-Petropoulou, 2003). Results and Discussion With increasing temperature TG indicates for all samples a loss of mass ranging from about 2 % to about 40 % (Fig. 1). Minimum and maximum desorption was found for Printex-G and Palas+OC, respectively. The thermograms of samples with high organic load show several distinct changes in slope which indicate the desorption of specific gasTable of particle samples used in this study |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://nanoparticles.ch/archive/2005_Karg_PO.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
