There is a need for affordable, rapid, trace-level (sub-ppm) chemical technology to characterize large numbers of samples to proactively ensure high-quality and safe agricultural and food products. This is especially true for wine and grapes where large numbers of samples require analyses to assess smoke taint exposure, characterize breeding programs, etc. Solid-phase microextraction (SPME) is widely used in conjunction with gas chromatography-mass spectrometry (GC-MS) for volatile analyses in

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... oodstuffs and other complex matrices. However, standard GC-MS quantitation methods generally require ~30-60 min per sample, making it suboptimal for high throughput analyses. Recent work from our lab has developed a method for the selective extraction and pre-concentration of volatiles which uses a planar sorbent sheet (SPMESH) headspace extraction prior to rapid analysis by Direct Analysis in Real Time (DART)-MS. Using this combined SPMESH-DART-MS approach, 24 samples could be extracted and analyzed in 45 min with detection limits of common odorants in the ng/L to µg/L range. While the original work using SPMESH-DART-MS was a substantial improvement over SPME-GC-MS, it still has its limitations. First, instead of being limited by a lengthy GC cycle, throughput is now limited by: (1) the equilibration time needed for a headspace extraction, (2) crosstalk within the system limiting the number of useable wells, and (3) the dimensions of the well plate itself. Additionally, the current range of compounds compatible with SPMESH-DARTiv MS is rather narrow. While SPMESH-DART-MS has previously worked well for non-polar, highly volatile compounds, it has poor performance with semi-polar volatiles and is incompatible with non-volatile compounds in headspace mode. This dissertation will describe efforts to overcome these challenges. v BIOGRAPHICAL SKETCH The author earned her bachelor's degree in Chemistry from the University of Southern California in 2015. After graduating from college, she moved to Atlanta, GA to work as an analytical chemistry fellow at the Centers for Disease Control and Prevention where she learned about solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). In August 2017, she joined the Sacks lab at Cornell University. Throughout her PhD, her research has focused on developing rapid, high-throughput methods for trace-level volatile compounds. After completing her degree, she will be joining the Food and Drug Administration in Denver, CO to work as a research chemist. vi ACKNOWLEDGEMENTS I would like to thank all the people that made this work possible. My minor committee members, Dr. Julie Goddard and Dr. Michael Gore, provided value feedback and advice. I would especially like to thank my advisor Dr. Gavin Sacks for his time and support, I learned a tremendous amount during my time in his lab. Dr. Sheng Zheng at the proteomics facility assisted with the high-resolution mass spectrometry analyses, Chris Alpha and Beth Rhoades at the Cornell NanoScale Facility helped manufacture SPMESH sheets, Robert Page at the machine shop made all the custom parts and the USDA-ARS Cornell team performed the UPC 2 -UV/VIS carotenoid analyses. Additionally, I would like to thank the faculty and staff in the Food Science department that allowed me to borrow equipment to perform experiments. I would also like to thank my friends and family that supported me throughout my PhD. Finally, I would like to thank all the members of the Sacks lab, I learned so much from them and made every day a joy. vii TABLE OF CONTENTS BIOGRAPHICAL SKETCH .