ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-5223-2010 Quantification of PM<sub>2.5</sub> organic carbon sampling artifacts in US networks Chow J. C. 1 2 Watson J. G. 1 2 Chen L.-W. A. 1 Rice J. 3 Frank N. H. 3 Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, Nevada, USA Institute of Earth Environment, Chinese Academy of Sciences, No. 10, Fenghui South Road, High-tech Zone, P.O. Box 17, Xian 710075, China Office of Air Quality Planning & Standards, US Environmental Protection Agency, 4201 Alexander Dr., Research Triangle Park, North Carolina, USA 15 06 2010 10 12 5223 5239 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/5223/2010/acp-10-5223-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/5223/2010/acp-10-5223-2010.pdf

Field blanks (bQF) and backup filters (quartz-fiber behind quartz-fiber filter; QBQ) have been adopted by US long-term air quality monitoring networks to estimate PM<sub>2.5</sub> organic carbon (OC) sampling artifacts. This study documents bQF and QBQ carbon levels for the: 1) Interagency Monitoring of Protected Visual Environments (IMPROVE); 2) Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]); and 3) Southeastern Aerosol Research and Characterization (SEARCH) networks and examines the similarities/differences associated with network-specific sampling protocols. A higher IMPROVE sample volume and smaller filter deposit area results in PM<sub>2.5</sub> areal density (μg/cm<sup>2</sup> on filter) 3–11 times those of STN/CSN and SEARCH samples for the same ambient PM<sub>2.5</sub> concentrations, thus reducing the relative contribution of sampling artifacts from passive OC adsorption. A relatively short (1–15 min) passive exposure period of STN/CSN and SEARCH bQF OC (0.8–1 μg/cm<sup>2</sup>) underestimates positive and negative OC artifacts resulting from passive adsorption or evaporation of semi-volatile organic compounds on quartz-fiber filters. This is supported by low STN/CSN and SEARCH bQF levels and lack of temporal or spatial variability among the sites within the networks. With a much longer period, ~7 days of ambient passive exposure, average IMPROVE bQF and QBQ OC are comparable (2.4&plusmn;0.5 and 3.1&plusmn;0.8 μg/cm<sup>2</sup>, respectively) and more than twice levels found in the STN/CSN and SEARCH networks. Sampling artifacts in STN/CSN were estimated from collocated IMPROVE samples based on linear regression. At six of the eight collocated sites in this study, STN/CSN bQFs underestimated OC artifacts by 11–34%. Using a preceding organic denuder in the SEARCH network minimized passive adsorption on QBQ, but OC on QBQ may not be attributed entirely to the negative sampling artifact (e.g., evaporated or volatilized OC from the front filter deposits after sample collection).

 References Arhami, M., Kuhn, T., Fine, P. M., Delfino, R. J., and Sioutas, C.: Effects of sampling artifacts and operating parameters on the performance of a semicontinuous particulate elemental carbon/organic carbon monitor, Environ. Sci. Technol., 40(3), 945–954, 2006. Arp, H. P. H., Schwarzenbach, R. P., and Goss, K. U.: Equilibrium sorption of gaseous organic chemicals to fiber filters used for aerosol studies, Atmos. Environ., 418241–8252, 2007. Ashbaugh, L. L., McDade, C. E., White, W. H., Wakabayashi, P., Collett Jr., J. L., and Xiao-Ying, Y.: Efficiency of IMPROVE network denuders for removing nitric acid, in Proceedings, Regional and Global Perspectives on Haze: Causes, Consequences and Controversies, 32-1-32-8, 2004. Cadle, S. H., Groblicki, P. J., and Mulawa, P. A.: Problems in the sampling and analysis of carbon particulate, Atmos. Environ., 17(3), 593–600, 1983. Chen, L.-W. A., Chow, J. C., Watson, J. G., Moosmüller, H., and Arnott, W. P.: Modeling reflectance and transmittance of quartz-fiber filter samples containing elemental carbon particles: Implications for thermal/optical analysis, J. Aerosol Sci., 35(6), 765–780, 2004. Chow, J. C. and Richards, L. W.: San Joaquin Valley Air Quaility Study/Atmospheric Utility Signatures - Predictions and Experiment (AUSPEX), Part E: Monitoring and analysis for aerosols and visibility, Volume II: Standard Operating Procedures, prepared for Pacific Gas and Electric Company, San Francisco, CA by Desert Research Institute, Reno, NV, 1990. Chow, J. C., Watson, J. G., Pritchett, L. C., Pierson, W. R., Frazier, C. A., and Purcell, R. G.: The DRI Thermal/Optical Reflectance carbon analysis system: Description, evaluation and applications in US air quality studies, Atmos. Environ., 27A(8), 1185–1201, 1993. Chow, J. C., Fujita, E. M., Watson, J. G., Lu, Z., Lawson, D. R., and Ashbaugh, L. L.: Evaluation of filter-based aerosol measurements during the 1987 Southern California Air Quality Study, Environ. Mon. Assess., 30(1), 49–80, 1994. Chow, J. C., Watson, J. G., Lu, Z., Lowenthal, D. H., Frazier, C. A., Solomon, P. A., Thuillier, R. H., and Magliano, K. L.: Descriptive analysis of PM$_2.5$ and PM$_10$ at regionally representative locations during SJVAQS/AUSPEX, Atmos. Environ., 30(12), 2079–2112, 1996. Chow, J. C., Watson, J. G., Crow, D., Lowenthal, D. H., and Merrifield, T. M.: Comparison of IMPROVE and NIOSH carbon measurements, Aerosol Sci. Technol., 34(1), 23–34, 2001. Chow, J. C., Bachmann, J. D., Wierman, S. S. G., Mathai, C. V., Malm, W. C., White, W. H., Mueller, P. K., Kumar, N. K., and Watson, J. G.: 2002 Critical review discussion - Visibility: Science and regulation, J. Air Waste Manage. Assoc., 52(9), 973–999, 2002a. Chow, J. C., Watson, J. G., Edgerton, S. A., and Vega, E.: Chemical composition of PM$_10$ and PM$_2.5$ in Mexico City during winter 1997, Sci. Total Environ., 287(3), 177–201, 2002b. Chow, J. C., Engelbrecht, J. P., Watson, J. G., Wilson, W. E., Frank, N. H., and Zhu, T.: Designing monitoring networks to represent outdoor human exposure, Chemosphere, 49, 961–978, 2002c. Chow, J. C., Watson, J. G., Chen, L.-W. A., Arnott, W. P., Moosmüller, H., and Fung, K. K.: Equivalence of elemental carbon by Thermal/Optical Reflectance and Transmittance with different temperature protocols, Environ. Sci. Technol., 38, 16, 4414–4422, 2004a. Chow, J. C., Watson, J. G., Kuhns, H. D., Etyemezian, V., Lowenthal, D. H., Crow, D. J., Kohl, S. D., Engelbrecht, J. P., and Green, M. C.: Source profiles for industrial, mobile, and area sources in the Big Bend Regional Aerosol Visibility and Observational (BRAVO) Study, Chemosphere, 54(2), 185–208, 2004b. Chow, J. C., Watson, J. G., Chen, L.-W. A., Paredes-Miranda, G., Chang, M.-C. O., Trimble, D., Fung, K. K., Zhang, H., and Zhen Yu, J.: Refining temperature measures in thermal/optical carbon analysis, Atmos. Chem. Phys., 5, 2961–2972, doi:10.5194/acp-5-2961-2005, 2005. Chow, J. C., Watson, J. G., Lowenthal, D. H., Chen, L.-W. A., and Magliano, K. L.: Particulate carbon measurements in California's San Joaquin Valley, Chemosphere, 62(3), 337–348, 2006. Chow, J. C., Watson, J. G., Chen, L.-W. A., Chang, M. C. O., Robinson, N. F., Trimble, D., and Kohl, S. D.: The IMPROVE_A temperature protocol for thermal/optical carbon analysis: Maintaining consistency with a long-term database, J. Air Waste Manage. Assoc., 57(9), 1014–1023, 2007. Chow, J. C., Doraiswamy, P., Watson, J. G., Chen, L.-W. A., Ho, S. S. H., and Sodeman, D. A.: Advances in integrated and continuous measurements for particle mass and chemical composition, J. Air Waste Manage. Assoc., 58(2), 141–163, 2008a. Chow, J. C., Watson, J. G., Chen, L.-W. A., Trimble, D. L., Ho, S. S. H., and Veropoulos, K.: Methods to assess carbonaceous aerosol sampling artifacts for IMPROVE and other long-term networks, prepared by Desert Research Institute, Reno, NV, 2008b. Chu, S. H.: PM$_2.5$ episodes as observed in the speciation trends network, Atmos. Environ., 38(31), 5237–5246, 2004. Chu, S. H., Paisie, J. W., and Jang, B. W. L.: PM data analysis – a comparison of two urban areas: Fresno and Atlanta, Atmos. Environ., 38(20), 3155–3164, 2004. Dutter, R. and Huber, P. J.: Numerical methods for the non linear robust regression problem, J. Stat. Comp. Simulation, 13(2), 79–113, 1981. Eatough, D. J., Sedar, B., Lewis, L., Hansen, L. D., Lewis, E. A., and Farber, R. J.: Determination of semivolatile organic compounds in particles in the Grand Canyon area, Aerosol Sci. Technol., 10438–10449, 1989. Eatough, D. J., Long, R. W., Modey, W. K., and Eatough, N. L.: Semi-volatile secondary organic aerosol in urban atmospheres: Meeting a measurement challenge, Atmos. Environ., 37(9–10), 1277–1292, 2003. Edgerton, E. S., Hartsell, B. E., Saylor, R. D., Jansen, J. J., Hansen, D. A., and Hidy, G. M.: The Southeastern Aerosol Research and Characterization Study Part II: Filter-based measurements of fine and coarse particulate matter mass and composition, J. Air Waste Manage. Assoc., 55(10), 1527–1542, 2005. El Zanan, H. S., Lowenthal, D. H., Zielinska, B., Chow, J. C., and Kumar, N. K.: Determination of the organic aerosol mass to organic carbon ratio in IMPROVE samples, Chemosphere, 60(4), 485–496, 2005. Eldred, R. A., Cahill, T. A., Wilkinson, L. K., Feeney, P. J., Chow, J. C., and Malm, W. C.: Measurement of fine particles and their chemical components in the NPS/IMPROVE Networks, in Transactions, Visibility and Fine Particles, edited by: Mathai, C. V., 187–196, 1990. Fan, X. H., Lee, P. K. H., Brook, J. R., and Mabury, S. A.: Improved measurement of seasonal and diurnal differences in the carbonaceous components of urban particulate matter using a denuder-based air sampler, Aerosol Sci. Technol., 38, Suppl. 2, 63–69, 2004. Fitz, D. R.: Reduction of the positive organic artifact on quartz filters, Aerosol Sci. Technol., 12(1), 142–148, 1990. Flanagan, J. B., Jayanty, R. K. M., Rickman Jr., E. E.,, and Peterson, M. R.: PM$_2.5$ Speciation Trends Network: Evaluation of whole-system uncertainties using data from sites with collocated samplers, J. Air Waste Manage. Assoc., 56(4), 492–499, 2006. Frank, N. H.: Retained nitrate, hydrated sulfates, and carbonaceous mass in Federal Reference Method fine particulate matter for six eastern cities, J. Air Waste Manage. Assoc., 56(4), 500–511, 2006. Hansen, D. A., Edgerton, E. S., Hartsell, B. E., Jansen, J. J., Kandasamy, N., Hidy, G. M., and Blanchard, C. L.: The Southeastern Aerosol Research and Characterization Study: Part 1 – Overview, J. Air Waste Manage. Assoc., 53(12), 1460–1471, 2003. Hart, K. M. and Pankow, J. F.: High-volume air sampler for particle and gas sampling 2. Use of backup filters to correct for the adsorption of gas-phase polycyclic aromatic hydrocarbons on the front filter, Enivron. Sci. Technol., 28(4), 655–661, 1994. Kajino, M., Winwarter, W., and Ueda, H.: Modeling retained water content in measured aerosol mass. Atmos. Environ., 40(27), 5202–5213, 2006. Kim, B. M., Cassmassi, J., Hogo, H., and Zeldin, M. D.: Positive organic carbon artifacts on filter medium during PM$_2.5$ sampling in the South Coast Air Basin, Aerosol Sci. Technol., 34(1), 35–41, 2001. Kim, E., Hopke, P. K., and Qin, Y.: Estimation of organic carbon blank values and error structures of the speciation trends network data for source apportionment, J. Air Waste Manage. Assoc., 55(8), 1190–1199, 2005. Kirchstetter, T. W., Corrigan, C. E., and Novakov, T.: Laboratory and field investigation of the adsorption of gaseous organic compounds onto quartz filters, Atmos. Environ., 35(9), 1663–1671, 2001. Lane, T. E., Donahue, N. M., and Pandis, S. N.: Simulating secondary organic aerosol formation using the volatility basis-set approach in a chemical transport model, Atmos. Environ., 42(32), 7439– 7451, 2008. Lewtas, J., Pang, Y., Booth, D., Reimer, S., Eatough, D. J., and Gundel, L. A.: Comparison of sampling methods for semi-volatile organic carbon associated with PM$_2.5$, Aerosol Sci. Technol., 34(1), 9–22, 2001. MacCracken, M. C.: Critical review: Prospects for future climate change and the reasons for early action, J. Air Waste Manage. Assoc., 58(6), 735–786, 2008. Mader, B. T. and Pankow, J. F.: Gas/solid partitioning of semivolatile organic compounds (SOCs) to air filters – 1. Partitioning of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polycyclic aromatic hydrocarbons to Teflon\textregistered membrane filters, Atmos. Environ., 34(28), 4879–4887, 2000. Mader, B. T. and Pankow, J. F.: Gas/solid partitioning of semivolatile organic compounds (SOCs) to air filters – 3. An analysis of gas adsorption artifacts in measurements of atmospheric SOCs and organic carbon (OC) when using Teflon\textregistered membrane filters and quartz fiber filters, Environ. Sci. Technol., 35(17), 3422–3432, 2001a. Mader, B. T. and Pankow, J. F.: Gas/solid partitioning of semivolatile organic compounds (SOCs) to air filters – 2. Partitioning of polychlorinated dibenzodioxins, polychlorinated dibenzofurans, and polycyclic aromatic hydrocarbons to quartz fiber filters, Atmos. Environ., 35(7), 1217–1223, 2001b. Malm, W. C., Sisler, J. F., Huffman, D., Eldred, R. A., and Cahill, T. A.: Spatial and seasonal trends in particle concentration and optical extinction in the United States, J. Geophys. Res., 99(D1), 1347–1370, 1994. Matsumoto, K., Hayano, T., and Uematsu, M.: Positive artifact in the measurement of particulate carbonaceous substances using an ambient carbon particulate monitor, Atmos. Environ., 37(33), 4713–4717, 2003. McDow, S. R. and Huntzicker, J. J.: Vapor adsorption artifact in the sampling of organic aerosol: Face velocity effects, Atmos. Environ., 24A(10), 2563–2571, 1990. Noll, J. and Birch, M. E.: Effects of sampling artifacts on occupational samples of diesel particulate matter, Environ. Sci. Technol., 42(14), 5223–5228, 2008. Olson, D. A. and Norris, G. A.: Sampling artifacts in measurement of elemental and organic carbon: Low-volume sampling in indoor and outdoor environments, Atmos. Environ., 39(30), 5437–5445, 2005. Peterson, M. R. and Richards, M. H.: Thermal-optical-transmittance analysis for organic, elemental, carbonate, total carbon, and OCX2 in PM$_2.5$ by the EPA/NIOSH method, in Proceedings, Symposium on Air Quality Measurement Methods and Technology-2002, edited by: Winegar, E. D. and Tropp, R. J., 83-1-83-19, 2002. Robinson, A. L., Donahue, N. M., Shrivastava, M. K., Weitkamp, E. A., Sage, A. M., Grieshop, A. P., Lane, T. E., Pierce, J. R., and Pandis, S. N.: Rethinking organic aerosols: Semivolatile emissions and photochemical aging, Science, 315(5816), 1259–1262, 2007. Salma, I., Ocskay, R., Chi, X. G., and Maenhaut, W.: Sampling artefacts, concentration and chemical composition of fine water-soluble organic carbon and humic-like substances in a continental urban atmospheric environment, Atmos. Environ., 41(19), 4106–4118, 2007. Solomon, P. A., Klamser, T., Egeghy, P., Crumpler, D., and Rice, J., STN/IMPROVE comparison study – Preliminary results, 2004. Subramanian, R., Khlystov, A. Y., Cabada, J. C., and Robinson, A. L.: Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations, Aerosol Sci. Technol., 38, Suppl. 1, 27–48, 2004. ten Brink, H. M., Maenhaut, W., Hitzenberger, R., Gnauk, T., Spindler, G., Even, A., Chi, X. G., Bauer, H., Puxbaum, H., Putaud, J. P., Tursic, J., and Berner, A.: INTERCOMP2000: The comparability of methods in use in Europe for measuring the carbon content of aerosol, Atmos. Environ., 38(38), 6507–6519, 2004. Tierney, G. P. and Conner, W. D.: Hygroscopic effects on weight determinations of particulates collected on glass-fiber filters, J. Am. Ind. Hyg. Assoc., 28, 363–365, 1967. Turpin, B. J., Huntzicker, J. J., and Hering, S. V.: Investigation of organic aerosol sampling artifacts in the Los Angeles Basin, Atmos. Environ., 28(19), 3061–3071, 1994. Turpin, B. J. and Lim, H. J.: Species contributions to PM$_2.5$ mass concentrations: Revisiting common assumptions for estimating organic mass, Aerosol Sci. Technol., 35(1), 602–610, 2001. USEPA: Guidance for network design and optimum site exposure for PM$_2.5$ and PM$_10$, prepared by US Environmental Protection Agency, Research Triangle Park, NC, USA, 1997. USEPA: 40 CFR Part 50: National Ambient Air Quality Standards for Particulate Matter; Final Rule, Federal Register, 71(200), 61144–61233, 2006a. US EPA: Modification of Carbon Procedures in the Speciation Network and FAQs, PM$_2.5$ Speciation Trends Network Newsletter, April, 2–3, 2006b. Vecchi, R., Valli, G., Fermo, P., D'Alessandro, A., Piazzalunga, A., and Bernardoni, V.: Organic and inorganic sampling artefacts assessment, Atmos. Environ., 43(10), 1713–1720, 2009. Viana, M., Chi, X., Maenhaut, W., Cafmeyer, J., Querol, X., Alastuey, A., Mikuska, P., and Vecera, Z.: Influence of sampling artefacts on measured PM, OC, and EC levels in Carbonaceous aerosols in an urban area, Aerosol Sci. Technol., 40(2), 107–117, 2006. Watson, J. G., Chow, J. C., Bowen, J. L., Lowenthal, D. H., Hering, S. V., Ouchida, P., and Oslund, W.: Air quality measurements from the Fresno Supersite, J. Air Waste Manage. Assoc., 50(8), 1321–1334, 2000. Watson, J. G.: Visibility: Science and regulation – A summary of the 2002 Critical Review, EM, 8, June, 36–43, 2002. Watson, J. G. and Chow, J. C.: Comparison and evaluation of in-situ and filter carbon measurements at the Fresno Supersite, J. Geophys. Res., 107, D21, ICC 3-1–ICC 3–15, 2002. Watson, J. G., Chow, J. C., Chen, L.-W. A., Kohl, S. D., Tropp, R. J., Trimble, D. L., Chancellor, S., Sodeman, D. A., and Ho, S. S. H.: Assessment of carbon sampling artifacts in the IMPROVE, STN/CSN, and SEARCH networks, prepared by Desert Research Institute, Reno, NV, USA, 2008. Watson, J. G. and Chow, J. C.: Ambient aerosol sampling, in Aerosol Measurement: Principles, Techniques and Applications, edited by: Kulkarni, P. S. and Baron, P., John Wiley and Sons, New York, NY, 2010. Watson, J. G., Chow, J. C., and Chen, L.-W. A.: Methods to assess carbonaceous aerosol sampling artifacts for IMPROVE and other long-term networks, J. Air Waste Manage. Assoc., 59(8), 898–911, 2009. White, W. H. and Roberts, P. T.: On the nature and origins of visibility-reducing aerosols in the Los Angeles air basin, Atmos. Environ., 11(9), 803–812, 1977. White, W. H. and Macias, E. S.: Carbonaceous particles and regional haze in the Western United States, Aerosol Sci. Technol., 10(1), 111–117, 1989. Yu, S. C., Dennis, R. L., Bhave, P. V., and Eder, B. K.: Primary and secondary organic aerosols over the United States: estimates on the basis of observed organic carbon (OC) and elemental carbon (EC), and air quality modeled primary OC/EC ratios, Atmos. Environ., 38, 5257–5268, 2004.