Abstract
Abstract. Intense new particle formation (NPF) events were observed in the coastal atmosphere during algae growth and farming season at Xiangshan gulf of the east China coast. High nucleation-mode iodine concentrations measured by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) confirmed that the NPF events were induced by iodine species. Our study provides important information on iodine speciation, size distributions, and its role in NPF in the context of heavy air pollution in China's coastal areas. For the first time, we identified 5 inorganic iodine species, 45 organic iodine compounds (35 molecular formulas), and a group of iodide–organic adducts in aerosols. The concentrations and size distributions of iodine species down to 10 nm were measured during the iodine-induced NPF, continental NPF, and non-NPF days at the coastal site and compared to those at an inland site. The iodine in the above four aerosol sample types were characterized by iodate, aromatic iodine compounds, iodoacetic acid or iodopropenoic acid, and iodide–organic adducts, respectively. Iodide and organic iodine compounds were found in the nucleation-mode particles; however, it is still not clear whether they contributed to nucleation or just new particle growth. Wild algae, as well as farmed algae, could be an important NPF source in China's coastal areas.
Highlights
Iodine is an essential trace element for all mammals and some aquatic plants
The purpose of our study is to characterize iodine speciation using the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) and measure their concentrations in size-segregated particles down to 10 nm diameter collected during the new particle formation (NPF) events observed at a coastal site of China
Based on the particle size distribution data, we identified two types of NPF events
Summary
Iodine is an essential trace element for all mammals (including human beings) and some aquatic plants. The atmospheric impact of iodine includes ozone (O3) depletion, altering HOx and NOx chemistry, mercury oxidation, and aerosol formation (Baker et al, 2001; O’Dowd et al, 2002a). Marine emission sources of iodine-containing species in the atmosphere – such as iodomethane, molecular iodine (I2), and hypoiodous acid (HOI) – include marine biota emission (Baker et al, 2000), sea surface iodide (I−) activation by O3 (Dixneuf et al, 2009; Mcfiggans et al, 2004; Palmer et al, 2005; Sellegri et al, 2006), and sea surface bubble bursting (Seto and Duce, 1972). Continental iodine sources include soil emission, fossil fuel and biomass combustions, and industrial emissions (Redeker et al, 2000; Sive et al, 2007).
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call