© 2016 LYDIA R. COOL ALL RIGHTS RESERVED IDENTIFYING AND DISTINGUISHING ISOMERS USING MASS SPECTROMETRY AND ION MOBILITY A Dissertation Presented to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Lydia R. Cool May, 2016 IDENTIFYING AND DISTINGUISHING ISOMERS USING MASS SPECTROMETRY AND ION MOBILITY Lydia R. Cool Dissertation Approved: Accepted: _____________________________ _____________________________ Advisor Department Chair Dr. Chrys Wesdemiotis Dr. Kim Calvo _____________________________ _____________________________ Committee Member Dean of the College Dr. Sailaja Paruchuri Dr. John Green _____________________________ _____________________________ Committee Member Dean of the Graduate School Dr. David Perry Dr. Chand Midha _____________________________ _____________________________ Committee Member Date Dr. Coleen Pugh _____________________________ Committee Member Dr. Claire Tessier ii ABSTRACT This dissertation focuses on the application of mass spectrometry (MS), tandem mass spectrometry (MS/MS), and ion mobility mass spectrometry (IM-MS) analysis of isomers. Chapter I gives an overview of the scope of the dissertation. Chapter II introduces mass spectrometry, including mass analyzers and ionization techniques. Chapter III discusses the instrumentation and materials used in this dissertation. Chapter IV discusses the analysis of five copolyesters. The first section of the chapter discusses two structural isomers synthesized using cyclohexane dicarboxylic acid (CHDA) and either 1,5-pentanediol (1,5-PED) or neopentyl glycol (NPG), viz. CHDA.NPG and CHDA.1,5-PED. Polyesters follow the 1,5-hydrogen rearrangement in MS/MS experiments, but CHDA.NPG cannot dissociate via this mechanism. A distinct, charge-induced fragmentation mechanism is proposed to operate in this case based on MS/MS fragmentation energetics and IM-MS results. The latter data serve a dual purpose as they can additionally be used to distinguish the two isomers. The second section of Chapter IV compares and contrasts the five isomers, which include oligomers made of adipic acid (AA) and ethylene glycol (1,2-EG). The hydrolysis behavior of the polyesters, which were synthesized by Mark D. Soucek et al. (University of Akron) are also discussed. Chapter V reports the analysis of a fluorinated polymer. Sample preparation difficulties necessitated the use of a supercharging agent in order to analyze the sample iii using ESI. Two different distributions were seen in the mass spectrum: linear and cyclic. Despite multiple theoretical structures being possible, only one structure was confirmed present for either the linear or cyclic distributions. The cyclic structure was determined to be a complete circle (macrocycle), whereas the linear structure was found to be completely linear with no branching. Chapter VI discusses multiple sets of monosaccharide-based isomers. Three different monosaccharides are included: α-D-mannopyranose, β-D-mannopyranose, and β-D-glucopyranose. Seven different substituents were made onto the monosaccharides. Tandem mass spectrometry cannot distinguish the isomers, but ion mobility mass spectrometry does. The IM-MS characteristics of the isomers followed a trend, independent of the substituent on the monosaccharides. Chapter VII summarizes the conclusions of the dissertation. This is followed by the references. Finally are the appendices, which include copyright permissions. iv DEDICATION To my husband Elijah, my son Landon, and the rest of my wonderful family. Your love and support has made each of these pages possible. v ACKNOWLEDGEMENTS First and foremost, I would like to thank Dr. Wesdemiotis for many years of help and support. Starting in my undergraduate career, his assistance throughout my research and academic career has been invaluable. His kindness and guidance throughout the past six years is greatly appreciated. I would like to thank my committee members: Dr. David Perry, Dr. Sailaja Paruchuri, Dr. Coleen Pugh, and Dr. Claire Tessier. Thank you very much for your help and support throughout graduate studies, and specifically with this dissertation. Thank you to the following group members: Vincenzo Scionti, Bryan Katzenmeyer, Aleer Yol, Nadrah Alawani, Xiumin Liu, Ahlam Alawiat, Michelle Kushnir, Sarah Robinson, Nick Alexander, Selim Gerislioglu, Sahar Sallam, Ivan Dolog, Jailin Mao, and Savannah Snyder. Their assistance in the lab has been invaluable. I’d also like to thank my undergraduate student, Jordan Robideau, for his dedication to research and all his hard work. I would like to thank Omnova Solutions Inc., particularly Dr. Matthew Espe, for the opportunity to gain professional experience by interning with them for two years. The following collaborators have contributed greatly to the following work: Cesar Lopez (Dr. Coleen Pugh, Department of Polymer Science), Matthew Quast (Dr. Anja Mueller, Central Michigan University), and Mayela Ramirez-Huerta (Dr. Mark Soucek, Department of Polymer Engineering). Additional collaborators have contributed vi to my graduate studies, although our work is not included in this dissertation, and I greatly appreciate the experience these collaborations provided. Last, but certainly not least, I would like to thank my family for their love and support. First of all, I would like to thank my husband, Elijah, for his unending dedication through these four years. I could not have finished this degree without your love and assistance. Second, to Landon, thank you for making every day an exciting adventure and for being the reason I worked so hard to finish. Third, I’d like to thank my parents, Crittenden and Carol Ohlemacher, for their support throughout my life and for encouraging me to follow my dreams and pursue higher education. Fourth, I would like to thank my mother-in-law Aimee Cool, for making me a member of her family from the very beginning and always taking an interest in my studies. Fifth, thank you to my sisters, Gwendolyn, Arielle, and Dominique, and brother-in-law, Nathan, for your support and your love. Lastly, to my in-laws, Chelsee, Joshua, and Granny, thank you for making me a part of your lives. vii TABLE OF CONTENTS Page LIST OF TABLES………………………………………………………………………..xi LIST OF FIGURES……………………………………………………………………...xii LIST OF SCHEMES…………………………………………………………………....xvi LIST OF ABBREVIATIONS…………………………………………………………xviii CHAPTER I. INTRODUCTION…………………………………………………………………….1 II. INSTRUMENTAL METHODS AND BACKGROUND…………………………….5 2.1 Mass Spectrometry……………………………………………………………5 2.2 Ionization Techniques………………………………………………………...7 2.2.1 Electrospray ionization (ESI)……………………………………….7 2.2.2 Matrix-assisted laser desorption ionization (MALDI)……………...9 2.3 Mass Analyzers……………………………………………………………...11 2.3.1 Quadrupole Mass Analyzer (Q)…………………………………...11 2.3.2 Time-of-flight Mass Analyzer (ToF)……………………………...13 2.4 Detectors…………………………………………………………………….15 2.4.1 Daly detectors……………………………………………………..16 2.4.2 Microchannel plate detectors……………………………………...17 2.5 Tandem Mass Spectrometry (MS/MS)……………………………………...18 2.5.1 Definitions…………………………………………………………19 viii 2.5.2 Collisionally activated dissociation (CAD)……………………….20 2.5.3 Types of fragmentation……………………………………………20 2.6 Ion Mobility Mass Spectrometry (IM-MS)………………………………….21 2.6.1 Travelling wave ion mobility spectrometry (TWIMS)……............22 2.6.2 Collision cross section (CCS)……………………………………..24 III. MATERIALS AND INSTRUMENTATION………………………………………..26 3.1 Materials…………………………………………………………………….26 3.2 Instrumentation……………………………………………………………...27 3.2.1 Synapt HDMS……………………………………………………..27 3.2.2 Bruker Ultraflex III………………………………………………..28 IV. POLYESTERS……………………………………………………………………….30 4.1 Introduction………………………………………………………………….30 4.2 Experimental Method………………………………………………………..33 4.2.1 Synthesis of polyesters…………………………………………….33 4.2.2 MALDI preparation……………………………………………….34 4.2.3 ESI preparation……………………………………………………35 4.2.4 Synapt Q/ToF Parameters ………………………………………...35 4.2.5 Survival Yield Calculations……………………………………….35 4.3 Results……………………………………………………………………….37 4.3.1 Analysis of CHDA.NPG and CHDA.1,5-PED……………………37 4.3.2 Analysis of AA.1,2-EG, CHDA.1,2-EG, and AA.NPG…………..55 4.4 Conclusions………………………………………………………………….66 ix V. HYPERBRANCHED FLUORINATED POLYMERS……………………………...67 5.1 Introduction………………………………………………………………….67 5.2 Experimental Methods………………………………………………………68 5.2.1 Synthesis of Fluorinated Polymers………………………………..68 5.2.2 MALDI Preparation……………………………………………….68 5.2.3 ESI Preparation…………………………………………................69 5.2.4 Synapt Q/ToF Parameters ………………………………………...69 5.3 Results……………………………………………………………………….70 5.4 Conclusions………………………………………………………………….86 VI. SUGAR-BASED STRUCTURAL ISOMERS………………………………………88 6.1 Introduction………………………………………………………………….88 6.2 Experimental Methods……………………………………………………….90 6.2.1 Synthesis of the Fluorinated Polymer……………………………..90 6.2.2 ESI Preparation…………………………………………................90 6.2.3 Synapt Q/ToF Parameters…………………………………………90 6.3 Results………………………………………………………………………..91 6.4 Conclusions…………………………………………………………………108 VII. SUMMARY……………………………………………………………………….109 REFERENCES…………………………………………………………………………112 APPENDICES………………………………………………………………………….124 APPENDIX A. COPYRIGHT PERMISSIONS……………………………….125 APPENDIX B. DERIVATION OF E50 EQUATION………………………….128 x LIST OF TABLES Table Page 4.1. Hydrolysis times of the various polyesters………………………………………34 4.2. The collision energies used for each oligomer of the five copolyesters…………35 4.3. Values of the coefficients and errors for the survival