<p> Comparison of atmospheric pressure ionization for the analysis of heavy petroleum fractions with ion mobility – mass spectrometry Mathilde Farenc a,b,g, Yuri E. Corilo c,d, Priscila M. Lalli c, Eleanor Riches f, Ryan P. Rodgers c,d,e, Carlos Afonso a,b, Pierre Giusti b,g a Normandie Univ, INSA Rouen, UNIROUEN, CNRS, COBRA, 76000 Rouen, France; b Joint Laboratory C2MC: Complex Matrices Molecular Characterization, Total Research & Technology, Gonfreville, BP 27, F-76700 Harfleur, France c Future Fuels Institute, 1800 East Paul Dirac Drive, Tallahassee, FL 32310; d National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, FL 32310 e Department of Chemistry and Biochemistry,95 Chieftain Way, Florida State University, Tallahassee, FL 32306. f Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, United Kingdom. g TOTAL Refining & Chemicals, Total Research & Technology Gonfreville, BP 27, 76700 Harfleur, France</p><p>Supporting information Figure S1: Full range mass spectra of the VGO before (Feed) HDT obtained with different ion sources.</p><p>Figure S2: Comparison of the VGO before (Feed) and after (Effluent) HDT obtained with different ion sources. C H S+• Feed Effluent 20 24 297.2584 297.2609 100 296.1584 100 296.2494 ASAP 296.2525 297.1646 % %</p><p>297.1262 296.0683 296.1586 297.1639 0 m/z 0 m/z 296 297 296 297 296.1599 297.2606 100 296.2511 100 296.2523 297.2595 APPI 297.1652 % %</p><p>296.0708 297.1289 296.1598 297.1657 0 m/z 0 m/z 296 297 296 297 297.2579 100 297.1661 100 APCI C H S 20 24 297.2590 % % 296.1540 296.2475 296.2452 297.1295 297.1642 296.1547 0 m/z 0 m/z 296 297 296 297</p><p>Figure S3. DBE vs. Carbon Number plot for the S1 class of VGO a) before and b) after</p><p>HDT by APPI+. Isomer 1 Isomer 2 Isomer 3</p><p>Isomer 6 Isomer 4 Isomer 5</p><p>Isomer 7 Isomer 8</p><p>+ Scheme S4. Hypothetical 3D structures of isomers with C22H32N elemental composition</p><p>1410269 APPI C.raw : 1</p><p>Figure S5. 2D raw data m/z vs drift time plot of VGO feed analyzed by APPI-</p><p>IMMS. Figure S6. Difference map obtained between the VGO sample before (feed) and after</p><p>(effluent) HDT obtained using the Waters HDMS compare 1.0 software.</p>