Time-Integrated Sampling Advances in the Measurement of Organic Molecular Markers in Urban Particulate Matter Presenter Monica Mazurek Civil & Environmental Engineering Department Rutgers University Session 2 Time-Integrated Sampling European Monitoring and Evaluation Program (EMEP) Workshop on Particulate Matter Measurement & Modeling, United Nations Economic Commission for Europe, New Orleans, LA April 19-23, 2004 Supported by NSF ATM, NESCAUM, EPRI, NYSERDA, American Chem. Council, U.S. EPA

Major Analytical Challenges Given the low ambient concentrations, how can individual marker compounds be measured precisely and accurately? How do sample collection, pretreatment and methods of detection impact identification and quantitation of individual marker in PM extract complex mixtures? Since identification and quantitation of known and new molecular tracers will be improved through better MS standards, community-based MS databases, additional source emission tests, how can this common use resource base be developed?

Carbon Chemical Mass Balance West Los Angeles (1982 annual average) Accounts for various forms of organic carbon Multiple analytical measurements Monitor variations in fine aerosol composition from bulk C to molecular organic C

Estimating Source Contribution Total C (EC+OC) : Organic Matter (1.4 X OC) : Elutable Organic Matter : Molecular Tracer Mass Emission Ratios hopane concentration ng/m3 OC concentration g/ m3 = ratio of source emission rates Rogge et al., 1993 vehicle exhaust = 2.7X10-3 Relative Source Contribution to Modeled OC Compounds Ambient Concentrations Diesel vehicles = 60% Gasoline Vehicles = 30% Paved road dust = 10% Schauer et al., 1996

Molecular Tracers in Ambient Fine PM West Los Angeles, CA April Molecular Tracers in Ambient Fine PM Sub parts-per-billion Collection, sample workup, analytical measurement system Time-integrated collection Composites or large air volumes needed, no sample replicate Mass quantitation MS based, requires authentic standards, MS reference spectra West Los Angeles, CA October

Tailoring Mass Spectrometer Instrumentation to Analyte Chemistry 100,000 10,000 1000 Nonpolar Very Polar GC/MS APCI API-Electrospray From Hewlett Packard/Agilent poster: “Fundamentals of Electrospray and Atmospheric Pressure Chemical Ionization LC/MS” 1997

Thank you

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