PAPER SPRAY MASS SPECTROMETRY for RAPID DRUG SCREENING by Rachel Jett
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PAPER SPRAY MASS SPECTROMETRY FOR RAPID DRUG SCREENING by Rachel Jett A Thesis Submitted to the Faculty of Purdue University In Partial Fulfillment of the Requirements for the degree of Master of Science Department of Chemistry Indianapolis, Indiana August 2017 ii THE PURDUE UNIVERSITY GRADUATE SCHOOL STATEMENT OF COMMITTEE APPROVAL Dr. Nick Manicke, Chair Department of Chemistry and Chemical Biology Dr. John Goodpaster Department of Chemistry and Chemical Biology Dr. Michael McLeish Department of Chemistry and Chemical Biology Approved by: Dr. Eric C. Long Head of the Graduate Program iii To the Creator- Who places the mysteries of the world before us and the curiosities of the mind within us iv ACKNOWLEDGMENTS This project would not have been possible without the input, support, and feedback of the Manicke and Goodpaster Groups: Nick, Chengsen, Brandon, Greta, Josiah, Grace, John, Dana, Will, Jordan, Clinton Thank you. v TABLE OF CONTENTS LIST OF TABLES ........................................................................................................... viii LIST OF FIGURES ............................................................................................................ x LIST OF ABBREVIATIONS .......................................................................................... xiv ABSTRACT ................................................................................................................. xv CHAPTER 1: BACKGROUND ......................................................................................... 1 Toxicology ...................................................................................................................... 1 Forensic Toxicology ....................................................................................................... 2 Human Performance Toxicology ................................................................................ 3 Doping Control ............................................................................................................ 3 Workplace Drug Testing ............................................................................................. 3 Postmortem Investigations .......................................................................................... 4 Analytical Strategy ......................................................................................................... 4 Targeted Analysis ........................................................................................................ 4 General Unknown Screening ....................................................................................... 5 Practical Toxicology .................................................................................................... 6 The Need for Something New ........................................................................................ 7 CHAPTER 2: INTRODUCTION ....................................................................................... 9 Project Overview ............................................................................................................ 9 Paper Spray-Mass Spectrometry .................................................................................. 10 Selectivity ..................................................................................................................... 14 Mass Spectrometer Selection .................................................................................... 14 Fragmentation ............................................................................................................ 15 Selectivity in Paper Spray ......................................................................................... 16 Special Considerations ................................................................................................. 18 Postmortem blood ...................................................................................................... 19 Matrix Effects ............................................................................................................ 20 CHAPTER 3: MATERIALS AND METHODS .............................................................. 23 Chemicals and Reagents ............................................................................................... 23 vi Mass Spectrometer and Materials ................................................................................ 23 Method .......................................................................................................................... 23 Manual Method ......................................................................................................... 24 Automated Method .................................................................................................... 26 CHAPTER 4: METHOD DEVELOPMENT.................................................................... 27 Solvent Selection .......................................................................................................... 27 Paper Shape and Sample Loading ................................................................................ 29 Placement of Sample................................................................................................ 30 Loading Capacity and Blood Dilution ..................................................................... 30 Tuning .......................................................................................................................... 36 Acquisition Parameter .................................................................................................. 38 Screening Identification Criteria .................................................................................. 39 CHAPTER 5: RESULTS .................................................................................................. 45 Results Summarized ..................................................................................................... 46 CHAPTER 6: INTERFERENCE STUDY ....................................................................... 67 Exogenous interferences ............................................................................................... 68 Intra-target interferences .............................................................................................. 68 Conclusions and Future Work ................................................................................. 76 CHAPTER 7: CONCLUSIONS ....................................................................................... 78 Summary of Conclusions ............................................................................................. 78 Discussion .................................................................................................................... 79 Future work .................................................................................................................. 80 BIBLIOGRAPHY ............................................................................................................. 82 APPENDIX A: PURPOSED ANALYTICAL TARGETS WITH CUTOFF VALUES FROM AFT .............................................................................................. 89 APPENDIX B: DETAILED RESULTS FROM LOADING CAPACITY AND BLOOD DILUTION STUDY ................................................................................. 108 APPENDIX C: MASS SPEC PARAMETERS .............................................................. 113 APPENDIX D: SPIKING SOLUTION COCKTAILS .................................................. 122 APPENDIX E: DETAILED DATA BY COCKTAIL ................................................... 126 APPENDIX F: EXOGENOUS INTERFERENCES ...................................................... 185 vii LIST OF TABLES Table 1: Screening cutoff values for the target anlaytes in the project ranged from less than 5 ng/mL to over 1000 ng/mL. ...........................................................11 Table 2: MS-MS based identification criteria for various applications .........................18 Table 3: 47 different solvent systems were tested for use with PS-MS in an effort to identify a solvent that would produce a steady Taylor cone, prevent electrical discharge, and effectively extract target analytes. ............................28 Table 4: Relative AUC of fragment ions at different positions on the long paper strip. The lowest AUC was normalized to 1.00 for comparative purposes and the position on the paper strip with the largest AUC is denoted in green. ................................................................................................................31 Table 5: Four dilutions schemes used to test the effect of diluting blood on the signal to blank ratio of five analytical targets. .................................................32 Table 6: Results from thirteen analytes show that using long paper with diluted blood generally gives lower blank signals and higher analyte response than using whole blood and 3mm punches. The first seven analytes (in blue) were run in one set of samples and the last 6 (in red) were run in a second set of samples. ..................................................................................................35 Table 7: A list of targets run at concentrations other than those proposed by AFT compared to normal, toxic, and fatal levels2 Normal levels are defined as the effective dose where no or minimal side effects occur. Toxic levels are those at which side effects or