Fig. 3.
Particle chemical evolution during the growth from laboratory experiments. (A) Reaction of I2O5 with meso-erythritol monitored by online APCI-MS analysis. I2O5 hydrolyzed in aerosol water leading to the production of IO3−, which can be seen from the m/z 175 signal. IO3− was rapidly reduced to form I2 upon introduction of meso-erythritol into the reaction system, inferred from a rapid decrease of IO3− signal and increase of I2− (m/z 254) signal. (B) Quantification of the released I2 formed from IO3− (product of I2O5 hydrolysis) reduction by alcohols or aldehydes in the particle phase. The molar ratio of organic/I2O5 is 100:1 except for benzaldehyde (50:1), and the pH of bulk solution is ∼3. Errors (2σ) ranged between 3.3% and 20.4% and were determined from triplicate runs of three individual experiments for each reaction.