Principal Component Analysis Approach for Determination of Stroke Protein Biomarkers and Modified Atmospheric Pressure Chemical Ionization Source Development for Volatile Analyses A dissertation submitted to the Graduate School Of the University of Cincinnati In partial fulfillment of the Requirements for the degree of DOCTORATE OF PHILOSOPHY In the Department of Chemistry Of the College of Arts and Sciences March 2017 By Keaton S. Nahan B.S., Forensic Science, Chestnut Hill College, Philadelphia, PA, May 2011 Committee Co-Chairs: Dr. Julio A. Landero Figueroa and Dr. Peng Zhang i Abstract Proteins play a role in neurological health and disorders. About 25% of proteins contain metals and these proteins are known as metalloproteins. Both blood plasma proteins and metalloproteins play an active role in stroke. These proteins may be quantified with approaches as simple as multiplexed assay to that of quantitative protein mass spectrometry (proteomics). Identification of present bound metals is more elusive. Inductively coupled plasma mass spectrometry (ICP-MS) is capable of both quantitation as well as speciation of metalloproteins when coupled with chromatography. Determination of metalloproteins, for use as a stroke determination tool, was performed by bottom up proteomics. Multivariate analysis was used to simplify the determination of important stroke biomarkers that were identified or quantified by quantitative multiplexed assays and tandem mass spectrometry, respectively. While ICP-MS was used as a means for determination of metal containing species, atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is used for quantitation of volatile species. Typical means of APCI-MS are coupled with chromatography for separations prior to quantitation or directly performed by flow injection. Alternatively, gas chromatography mass spectrometry (GC-MS) also is capable of separating volatile molecules at low levels by using solid phase microextraction (SPME) fibers. In order to improve APCI-MS, it was proposed to modify an APCI source to incorporate a conductive SPME source that was capable of low solvent analysis for detection of volatile species. While commercial SPME fibers are produced from a variety of polymers, this modified APCI source was produced from multiwalled carbon nanotubes (MWCNT’s) to ensure flexibility, improved surface area, and conductivity. ii iii Acknowledgments I dedicate my dissertation to the late Dr. Joseph “Doc” Caruso. When I began at the University of Cincinnati, I had my own difficulties, but Doc took me into the research group anyways. He always made me feel like a part of the group and that he was the head of the research group family. If I ever had a lousy day, Doc always knew the perfect joke to tell. Some of my favorite moments with Doc were fixing things around the lab with him. He showed me how to plumb a water circulator, adhere polymer pipes, and what a passionate chemist looks like. He was as intelligent as he was warm-hearted. The parties that Doc and Judy Caruso held at their home were always a blast. Their family and our research group shared laughs as much as we enjoyed the sound of Doc playing the accordion. Doc and Judy made me and the rest of the group feel like family. I will never forget what Doc gave me and I will continue to become the greatest chemist I can become. I would like to thank Dr. Julio Landero for mentoring me in everything from fixing instruments to the theory of instrumentation. He was able to convey many topics at a level I could understand in order to succeed in my projects. Most of all, I want to thank him for taking the heavy responsibility of the research group after Doc’s passing. While many were worried about what was going to happen next, Dr. Landero made it clear that he would be there to support us until we finished. As my advisor, he spent a substantial amount of time helping me with my manuscripts as well as preparing me for the future. When I needed a reality check, he gave me his blunt opinion and it was always appreciated to keep me on track for graduation. I want to thank my committee Dr. Ridgway, Dr. Zhang, and Dr. Stan. You have aided me in my research decisions, improved my critical thinking, and turned me into a level headed chemist. During my first year in teaching, I was the teaching assistant in general chemistry lab for Dr. Anne Vonderheide. After working with Dr. Vonderheide my first year, I had received an iv opportunity to work on a mass spectrometer in the analytical laboratory with her. At that moment, I had gained a deep insight into using the mass spectrometer and understanding its intricacies. After discussing an experiment with Dr. Vonderheide, I was allowed to modify the mass spectrometer to my heart’s content, which led me to another project that was inspired by my interest in instrumentation. I can’t thank her enough for allowing me to work mass spectrometric instrumentation as well as her aid in helping me gains funds for my 6th year. Dr. V has been an excellent mentor. Dr. Vonderheide also introduced me to Dr. Vesselin Shanov and Dr. Noe Alvarez who have provided me with the nanomaterials essential for my project as well as aided me in improving the ionization source apparatus. Their help has been essential in making this project successful. I would like to thank Dr. Anna Gudmundsdottir for providing funds from the department to finish my education during my 6th year of graduate school. I want to thank Dr. Stephan Macha and Dr. Larry Sallans for allowing me to ask them numerous questions about mass spectrometry as well as letting me borrow seemingly miscellaneous tools. They were quick to give me in-depth answers and suggestions. During my time at UC, I was lucky to have been in such a great research group. I want to thank Amberlie Clutterbuck, Anna Donnell, Skyler Smith, Jiawei Gong, Phanichand Kodali, Karnakar Chitta, Cory Stiner, and Megan Stanton for being great peers to work with. I want to highlight Anna Donnell for being a great peer mentor for my growth as a mass spectrometrist, chemist, and teacher. Also, I am happy to have made friends with visiting scholars: Oliver Hochmoller, Aline Olivieri, Tina Wigger, and Dr. Maria Hespanhol. v Over the years at UC, I made many friends including Travis Pollard, Gus Powers, Brett Bolton, Vianessa Ng, Rob Ross, Xiaoyu Cao, Jennifer Vernia, Daoli Zhao, Xuefei Guo, Tingting Wang, and Li Duan. I cherish the laughs, discussions, and parties we shared. I want to especially thank Rob and Xiaoyu for reintroducing me to Wenwen. Most of all, I want to thank my beautiful wife, Wenwen Yang. Ever since we started dating in 2013, she has stood by, supported me, and motivated me to achieve greater success. I will vi always remember December 30, 2015 as the happiest day of my life. She is my other half and I can’t imagine making it out of graduate school without her. Even when I had to do my research on a broken foot, she would help me in whatever way she could. She always drove me to the easiest entrances to get in with crutches and told me when I was pushing myself too hard. Wenwen is my constant source of inspiration. We are in for a great future together, dear, and I will lead the way. vii Table of Contents Page Table of Figures..........................................................................................................................xi Table of Tables..........................................................................................................................xii 1. Chapter 1:Introduction.........................................................................................................1 1.1. Preface 1.2. Sample Preparation 1.2.1. Acid Sample Dissolution 1.3. Instrumentation 1.3.1. Molecular Mass Spectrometry 1.3.1.1. Ionization 1.3.1.1.1. Chemical Ionization 1.3.1.1.2. Electrospray Ionization 1.3.1.1.3. Atmospheric Pressure Chemical Ionization 1.3.1.1.4. Desorption Electrospray Ionization 1.3.1.1.5. Direct Probe Atmospheric Pressure Chemical Ionization 1.3.1.1.6. Atmospheric Solids Analysis Probe 1.3.1.1.7. Desorption Atmospheric Pressure Chemical Ionization 1.3.1.2. Sample Introduction 1.3.1.2.1. Infusion and Flow Injection Analysis 1.3.1.2.2. Solid Phase Microextraction 1.3.1.2.2.1. Carbon Nanotube Solid Phase Microextraction Fibers 1.3.1.2.3. Liquid Chromatography 1.3.1.2.3.1. Affinity Chromatography 1.3.1.2.3.2. Reverse Phase Chromatography viii 1.3.2. Inductively Coupled Plasma Mass Spectrometry 1.3.2.1. Ionization, Nebulization, and Transport 1.3.2.2. Interferences in Atomic Mass Spectroscopy 1.3.2.3. Detection 1.3.2.4. Speciation 1.4. Statistics 1.4.1. Univariate Statistics 1.4.2. Multivariate Statistics 1.4.2.1. Data Pretreatment 1.4.2.2. Principal Component Analysis 1.5. Applications 1.5.1. Applications of Metallomics and Disease 1.5.2. Applications of Volatile Organic Molecule Determination 1.5.2.1. Chemical Warfare Agents 1.5.2.2. Mars 2. Chapter 2. The Metalloprotein and Metal Profile of Human Blood Plasma as a Diagnostic Fingerprint for Stroke Determination.............................................................30 2.1. Abstract 2.2. Introduction 2.3. Methods 2.3.1. Blood Plasma Acquisition 2.3.2. Reagents 2.3.3. Apparatus 2.3.4. Procedure 2.3.4.1. Trace Metal Analysis 2.3.4.2. Immunodepletion and SEC-ICP-MS/MS ix 2.3.5. Metalloprotein Identification by LC-MS/MS 2.3.6. Statistical Analyses 2.3.6.1. Software 2.3.6.2. Data Pretreatment 2.4. Results and Discussion 2.4.1. ICP-MS/MS 2.4.2. SEC-ICP-MS/MS Metalloprotein Analyses 2.4.3. Multivariate Analysis 2.4.4.