title: Comparison of PM2.5 carbon measurement methods in Hong Kong, China.
abstract: Samples from Hong Kong, China, were analyzed for organic carbon (OC), elemental carbon (EC), and total carbon (TC) by three thermal protocols (low-temperature IMPROVE and high-temperature STN and NIOSH) and two optical monitoring methods: reflectance and transmittance. Good agreement (+/-10%) for TC among the three protocols was observed for sample loadings of 1-55 microg m(-3). The two protocols using a reflectance pyrolysis correction showed best agreement for EC, with <20% differences found for approximately 80% of the samples. Hong Kong has a large diesel fleet, and for some heavily loaded samples the light transmittance was too low for quantitative detection, resulting in large uncertainties in the OC/EC split based on transmittance. Hong Kong experienced OC levels similar to those at US sites, but has much higher EC concentrations. OC/EC ratios range from 2 to 5 at two US sites and from 0.2 to 1.2 at three Hong Kong sites.
authors.affiliation: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA. judy.chow@dri.edu
authors.forename: Judith C
authors.initials: JC
authors.lastname: Chow
authors.forename: John G
authors.initials: JG
authors.lastname: Watson
authors.forename: Peter K K
authors.initials: PK
authors.lastname: Louie
authors.forename: L-W Antony
authors.initials: LW
authors.lastname: Chen
authors.forename: Della
authors.initials: D
authors.lastname: Sin
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006723:Hong Kong; D055095:Optics and Photonics; D010316:Particle Size; D012680:Sensitivity and Specificity; D001335:Vehicle Emissions
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D001335:Vehicle Emissions; D002244:Carbon