title: Quantification of elemental and organic carbon in atmospheric particulate matter using color space sensing-hue, saturation, and value (HSV) coordinates.
abstract: A fast and cost effective application of color sensing was used to quantify color coordinates of atmospheric particulate matter collected on filters to quantify elemental and organic carbon (EC/OC) loading. This is a unique and novel approach for estimating OC composition. The method used a colorimeter and digital photography to obtain XYZ color space values and mathematically transformed them to HSV cylindrical-coordinates; a quantification method was applied to estimate the NIOSH and IMPROVE (TOR) EC/OC loadings from a set of globally diverse PM samples. When applied to 315 samples collected at three US EPA Chemical Speciation Network (CSN) sampling sites, the HSV model proved to be a robust method for EC measurement with an R(2)=0.917 for predicted versus measured loading results and a CV(RMSE)=16.1%. The OC quantified from the same sample filters had an R(2)=0.671 and a CV(RMSE)=24.8% between the predicted and measured results. The method was applied to NIOSH EC/OC results from a set of samples from rural China, Bagdad, and the San Joaquin Valley, CA, and the EC and OC CV(RMSE) were 30.8% and 49.3%, respectively. Additionally, the method was applied to samples with color quantified by a digital photographic image (DPI) with EC results showing good agreement with a CV(RMSE) of 22.6%. OC concentrations were not captured as accurately with the DPI method, with a CV(RMSE) of 77.5%. The method's low analytical cost makes it a valuable tool for estimating EC/OC exposure in developing regions and for large scale monitoring campaigns.
authors.affiliation: University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Olson
authors.affiliation: Nexleaf Analytics, 2356 Pelham Ave., Los Angeles, CA 90064, USA; Central Washington University, Department of Biology, Ellensburg, WA 98926, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Graham
authors.affiliation: University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA.
authors.forename: Samera
authors.initials: S
authors.lastname: Hamad
authors.affiliation: University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA.
authors.forename: Pajean
authors.initials: P
authors.lastname: Uchupalanun
authors.affiliation: Nexleaf Analytics, 2356 Pelham Ave., Los Angeles, CA 90064, USA.
authors.forename: Nithya
authors.initials: N
authors.lastname: Ramanathan
authors.affiliation: University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA. Electronic address: jjschauer@wisc.edu.
authors.forename: James J
authors.initials: JJ
authors.lastname: Schauer
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon
keywords: Color space; Elemental and organic carbon; HSV predictive model; Hue saturation and value