title: Characterization and seasonal variations of levoglucosan in fine particulate matter in Xi'an, China.
abstract: PM2.5 (particulate matter with an aerodynamic diameter <2.5 microm) samples (n = 58) collected every sixth day in Xi'an, China, from 5 July 2008 to 27 June 2009 are analyzed for levoglucosan (1,6-anhydro-beta-D-glucopyranose) to evaluate the impacts of biomass combustion on ambient concentrations. Twenty-four-hour levoglucosan concentrations displayed clear summer minima and winter maxima that ranged from 46 to 1889 ng m(-3), with an average of 428 +/- 399 ng m(-3). Besides agricultural burning, biomass/biofuel combustion for household heating with straws and branches appears to be of regional importance during the heating season in northwestern China. Good correlations (0.70 < R < 0.91) were found between levoglucosan relative to water- soluble K+, Cl-, organic carbon (OC), elemental carbon (EC), and glyoxal. The highest levoglucosan/OC ratio of2.3% wasfound in winter, followed by autumn (1.5%). Biomass burning contributed to 5.1-43.8% of OC (with an average of 17.6 +/- 8.4%).
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Jun-Ji
authors.initials: JJ
authors.lastname: Cao
authors.forename: Judith C
authors.initials: JC
authors.lastname: Chow
authors.forename: Zhen-xing
authors.initials: ZX
authors.lastname: Shen
authors.forename: Kin-Fai
authors.initials: KF
authors.lastname: Ho
authors.forename: Steven Sai Hang
authors.initials: SS
authors.lastname: Ho
authors.forename: Sui-Xin
authors.initials: SX
authors.lastname: Liu
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Han
authors.forename: John G
authors.initials: JG
authors.lastname: Watson
authors.forename: Ge-Hui
authors.initials: GH
authors.lastname: Wang
authors.forename: Ru-Jin
authors.initials: RJ
authors.lastname: Huang
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005390:Fires; D005947:Glucose / Q000031:analogs & derivatives* / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D012621:Seasons
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; C014989:1,6-anhydro-beta-glucopyranose; D005947:Glucose