When all the available data was considered, no clear pH dependence of low-volatility material formation was found.
Comparison between the kinetic model and experimental data suggests significant particle phase processing forming low-volatility material such as organic salts.
A number of mechanisms forming low-volatility material in aqueous solutions containing inorganic salts and dicarboxylic acids have been reported in the literature, including reactions between NaCl and organic acids, formation of organosulfates and -nitrates in the presence of AS and sulfuric acid, and different self-cycling/oligomerization reactions.
Based on the consistent results between this study and the study by Laskin et al., organic salt formation due to evaporation of HCl can be considered as the main candidate for low-volatility material formation within mixtures of organic acids and NaCl.
The magnitude of low-volatility organic material formation at an atmospherically relevant pH range indicates that the observed phenomenon is not only significant in laboratory conditions but is also of direct atmospheric relevance.
Concerning our experiments and relatively fast drying process, the formation of organonitrates or -sulfates is not expected, or at least, it cannot explain all the observed low-volatility organic material.
Particulate-phase chemical reactions in mixtures of organic acids with amines, and with monovalent and divalent inorganic salts, have been reported to lead to formation of low-volatility organic material.
Even without acid removal from the aerosol, organic salt formation, as observed within organic acid/divalent inorganic salt mixtures (e.g., oxalic acid/CaSO4), is a plausible explanation for the low-volatility organic material also in submicron organic acid/AS aerosol.
Our technique allows us, for the first time, to quantify the amount of low-volatility organic material formed in these aerosol mixtures, and its dependence on the mixture properties and atmospheric conditions.
He added that "recent volatility in raw material prices, however, makes first-quarter forecasting difficult" and that income probably will be lower in the January to March quarter than in the October to December period.
The M100 started thinking about the basic risks of owning a chemicals company like Eastman Chemical: the cyclicality of the chemicals industry and the volatility of raw material costs.
