1. Organic Chemistry - Carbon Compounds Carbon - C, atomic number 6, molecular weight 12 Electron configuration: 1s 2 2s 2 2p 2 Tetravalent – 4 single bonds (sp 3 ); 2 double bonds (sp 2 ) one triple (sp) plus one single bond Other atoms: hydrogen, oxygen, nitrogen, sulfur, halogens (Cl, F, Br)

2. Compounds Alkanes – C n H 2n+2 (CH 4, C 2 H 6, etc) Alkenes – C n H 2n (C 2 H 4, etc) Alkynes - C n H 2n-2 (C 2 H 2 ) Aromatic compounds (C 6 H 6, benzene) Polycyclic aromatic hydrocarbons - PAH (naphthalene, C 10 H 8 )

3. Models Methane Ethane

4. Pentane Ethylene (Etene)

5. Benzene Ethanol

6. Sources of Organics in Air Anthropogenic: –Incomplete combustion of fossil fuels –Biomass burning –Industrial processes –Cooking Natural sources –Biogenic emissions (from vegetation) –Volcanic –Evaporation of sea spray Atmospheric reaction products (from VOC, SVOC), secondary organic aerosol (SOA)

7. Fossil fuels

8. Biomass Burning

9. Other sources - testing

10. Secondary Organic Aerosol (SOA) SOA processes are studied in photoreactors European photoreactor (EUPHORE) in Valencia, Spain, is one of the largest (200 m 3 ) and the best- equipped outdoor simulation chamber in the world We are studying atmospheric transformation of diesel emissions under the influence of sunlight, ozone, hydroxyl radicals that occur during transport in ambient air

11. VOC, SVOC and PM Vapor pressure ranges: VOC: > 10 2 Pa (10 -1 Torr) SVOC: 10 2 and 10 -6 Pa; (10 -1 and 10 -8 Torr) PM: < 10 -6 Pa (10 -8 Torr)

12. Hazardous Air Pollutants (HAPs) Full list – 188 compounds, most of them organics The short list – 33 air toxics, most prevalent in urban area No ambient standards – regulation of emissions from sources

13. 1. acetaldehyde18. formaldehyde 2. acrolein19. hexachlorobenzene 3. acrylonitrile20. hydrazine 4. arsenic compounds21. lead compounds 5. benzene22. manganese compounds 6. beryllium compounds23. mercury compounds 7. 1, 3-butadiene24. methylene chloride 8. cadmium compounds25. nickel compounds 9. carbon tetrachloride26. perchloroethylene 10. chloroform27. polychlorinated biphenyls (PCBs) 11. chromium compounds28. polycyclic organic matter (POM)* 12. coke oven emissions29. propylene dichloride 13. 1, 3-dichloropropene30. quinoline 14. diesel particulate matter31. 1, 1, 2, 2-tetrachloroethane 15. ethylene dibromide32. trichloroethylene 16. ethylene dichloride33. vinyl chloride 17. ethylene oxide

14. Criteria Pollutants – National Ambient Air Quality Standards (NAAQS) Particulate Matter (PM) Ozone NOx SO 2 CO Lead (Pb)

15. Why Particulate Matter? Health effects: particulate matter (fine, PM 2.5 and to lesser degree, coarse PM 10-2.5 ) has been associated with adverse health effects at low-to-moderate concentrations NAAQS exist for PM (since 1971): –current (since 1997): PM 2.5 annual 15 µg/m 3 and 24-hr 65 µg/m 3 ; PM 10 annual 50 µg/m 3 and 24-hr 150 µg/m 3 _ announced in September 2006: PM 2.5 annual 15 µg/m 3 and 24-hr 35 µg/m 3 ; PM 10 annual only Climate change Visibility problem (Haze Rule)

16. Average Ambient PM 2.5 Composition in Urban Areas EPA STN network

17. Average PM 10-2.5, PM 2.5, and PM 0.1 composition at EPA “supersite” in Los Angeles, CA, 10/2001 to 9/2002 US EPA OAQPS PM Staff Paper, June 2005

18. Organic Aerosol Organic aerosols are solid or liquid particles suspended in the atmosphere containing organic carbon Semi-volatile organic compounds (SVOC) - distributed between gas and particle phases – reversibly condensable Particle associated organics – complex mixture, incorporated into/onto particles; includes condensed SVOC and non-volatile organic compounds

19. Measurement Methods Collection of VOC and aerosol samples followed by off-site laboratory analyses VOC collection: stainless steel SUMMA canisters PM and SVOC: Filters followed by solid adsorbents

20. Operational Definitions of SVOC and PM - Associated OC Filter-Adsorbent (FA) AFAF D Denuder-Filter- Adsorbent (DFA) A E Electrostatic precipitator (EA) Filter-Filter- Adsorbent (FFA) F1F1 FA

21. Analysis - Chromatography Chromatography is a separation method that relies on differences in partitioning behavior between a flowing mobile phase and a stationary phase to separate the components in a mixture.

22. Gas Chromatography (GC)

23. Examples of "hyphenated techniques" include gas and liquid chromatography with mass spectrometry (GC-MS and LC- MS), Fourier-transform infrared spectroscopy (GC-FTIR), and photo diode- array UV-VIS absorption spectroscopy (HPLC-UV-VIS). HPLC - liquid chromatography that utilizes high-pressure pumps to increase the efficiency of the separation