Comparison of PM2.5 carbon measurement methods in Hong Kong, China.
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.
Chow
Judith C
JC
Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA. judy.chow@dri.edu
Watson
John G
JG
Louie
Peter K K
PK
Chen
L-W Antony
LW
Sin
Della
D
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
D000336:Aerosols; D000393:Air Pollutants; D001335:Vehicle Emissions; D002244:Carbon