1. Background Aerosols are studied for –Environment impact Direct climate effect Indirect climate effect –Biofuels –Human health impact Medicinal Cigarette smoke Direct effect: smog, decreased visibility Indirect effect: acid rain, damage to historic landmarks

2. Introduction Ambient organic aerosol –Heterogeneous composition –Secondary reactions occur in particle Off-line filter sampling –Longer analysis times –Allows secondary reactions to occur to a greater extent Mass spectrometry –Real-time analysis –Structural information –Range of compounds

3. Mass Spectrometry for Aerosol Analysis Real time analysis –Ambient sampling –MS n capabilities –Transportability Quadrupole ion trap –Compact –High sensitivity –High MS/MS efficiency

4. Py-LTPI Ionization Method

5. Experimental Bruker Esquire 3000 50 mg sample pyrolyzed 5 minute equilibration prior to analysis ~2 minutes to reach maximum temperature Spectra averaged over the course of pyrolysis

6. Cellulose and Lignin Natural polymers Primary components of cell wall Contain mostly carbon, hydrogen, and oxygen Cellulose Lignin

7. Py-LTPI of Cellulose 97 111 127 137 143 149 163 177 191 205 219 229 243 257279 0.0 0.5 1.0 1.5 2.0 Intensity x 10 5 100120140160180200220240260280 m/z Mass-to-charge ratios can be compared to previously identified compounds Positive Ion Detection Mode Negative Ion Detection Mode 113.3 127 141 157 171 185 205 227 241 255 269 277 283 0 500 1000 1500 2000 Intensity 100120140160180200220240260280 m/z

8. Previously Identified Compounds in Cellulose 3,5-dihydroxy-2-methyl-4H-pyran-4-one 142 Da 5-hydroxymethyl-furfural 126 Da Furfural 96 Da Levoglucosenone 126 Da Levoglucosan 162 Da 2-methyl-3-hydroxy-4-pyrone 126 Da Syringaldehyde 182 Da 4-ethylsringol 182 Da 2,6-dimethoxyphenol 154 Da Some previously identified compounds have the same mass and will have the same mass-to-charge ratios.

9. Tandem Mass Spectrometry (MS/MS) Used to differentiate between ions of the same mass-to-charge ratio Ions are subjected to collision- induced dissociation (CID) –Ions dissociate into product ions –Ions can be differentiated by dissociation patterns

10. 3-Hydroxy-2-Methyl-4-Pyrone Standard 69 71 81 83 85 97 99 109 127 0 1000 2000 3000 Intensity 60708090100110120 m/z Cellulose Aerosol Product MS/MS of 127 Da Only two common fragment ions and the relative intensities for 127 and 109 are dissimilar. Unlikely a compound in cellulose aerosol.

11. 95 123 140 155 0 2 4 6 8 Intensity x 10 5 8090100110120130140150 m/z 2,6-Dimethoxyphenol Standard Cellulose Aerosol Product MS/MS of 155 Da All fragment ions of 2,6-Dimethoxyphenol match fragment ions of cellulose aerosol. 2,6-Dimethoxyphenol could be a compound in cellulose aerosol.

12. Cellulose Summary MS/MS by CID allows for comparison of cellulose aerosol product to standards Some peaks match those of standards and could be found in aerosol product Some peaks do not match previously identified compounds

13. Py-LTPI of Lignin 110 124 138 151 165 179 191 207227241 249 255 269 279 0 2 4 6 Intensity x 10 4 100120140160180200220240260280 m/z Positive Ion Detection Mode Negative Ion Detection Mode 112 124 141 149. 154 167 182196 210 219 233 247 257 271 279 287. 0 2000 4000 6000 8000 Intensity 100120140160180200220240260280 m/z Can the same previously identified compounds from be found in lignin?

14. 95 123 140 155 0 2 4 6 8 Intensity x 10 5 8090100110120130140150 m/z 2,6-Dimethoxyphenol Standard Lignin Aerosol Product MS/MS of 155 Da 86 99 109 113 123 127 137 140 152 0 200 400 600 800 1000 Intensity 8090100110120130140150 m/z Not all of the fragment ions of standard match the aerosol product and the relative intensities of fragment ion 127 are dissimilar. Unlikely a compound in lignin aerosol.

15. MS/MS of 127 Da 3-Hydroxy-2-Methyl-4-Pyrone Standard Lignin Aerosol Product 69 81 83 85 97 99 109 127 0 100 200 300 400 500 Intensity 60708090100110120 m/z 71 At the same CID voltage, the standard and aerosol product yield different relative intensities for ions 127 and 109. Unlikely a compound in pyrolyzed lignin aerosol.

16. Unexpected Losses 83 97 111 121 129 139. 147 157 175 0 50 100 150 Intensity 8090100110120130140150160170 m/z 75 87 97 111 125 141 143 159 169 187 0 10 20 30 40 Intensity 80100120140160180 m/z 172 Parent ion: 157; Net loss of 10; possible loss of 28 and gain of 18 Loss of 15; possible loss of a methyl radical

17. Conclusions Some previously identified standards match well with the cellulose aerosol product The same standards do not match well with ions in lignin aerosol product Unexpected losses of 15 Da and 10 Da

18. Future Work Further investigation of cellulose and lignin aerosol products –Comparison of previous identified compounds in negative mode –Comparison of other cellulose and lignin standards Investigation of cellulose and lignin using Pyrolysis Extractive Electrospray Ionization (Py-EESI)

19. References 1. Evans, R. J., Milne, T. A. Molecular Characterization of the Pyrolysis Biomass. 1. Fundamentals. Energ Fuel, 1987, 1, 123-137. 2. Lu, Q., Yang, X.-C., Dong, C.-Q., Zhang, Z.-F., Zhang, X.-M., Zhu, X.-F. Influence of pyrolysis temperature and time on the cellulose fast pyrolysis products: Analytical Py=GC/MS study. J Anal App Pyrol, 2011, 92, 430-438.

20. Acknowledgements Thank you to R. J. Reynolds for funding this project Glish Group