Development of Mass Spectrometry-Based Analytical Assays for Environmental and Chemical Defense Applications

Abstract

Mass spectrometry (MS) is a powerful and versatile technique that is useful for addressing a wide range of complex analytical challenges. In this work, mass spectrometry-based assays were developed to address issues relating to environmental contamination and for detecting analytes of interest to the defense industry. Chapter one is an overview of the history of mass spectrometry, the fundamental operation of a mass spectrometer, as well as, advancements in chromatographic separation and ionization methods. Chapter two focuses on the development of an assay that uses blow flies as environmental sensors of chemical weapon release. In that work, a liquid chromatography – tandem mass spectrometry (LC-MS/MS) method was developed to detect chemical warfare agent simulants and chemical warfare agent hydrolysis products in flies exposed to the chemicals in controlled feeding experiments. The work in chapter three describes the development of a surface enhanced Raman spectroscopy assay coupled to paper spray mass spectrometry for a more fieldable and environmentally friendly approach to detect organophosphorus compounds. Chapter four describes the development of a paper spray mass spectrometry assay for the detection and semi-quantitation of per- and polyfluoroalkyl substances in whole blood without sample cleanup or chromatographic separations. This method would be useful in detecting high levels of these carcinogenic compounds in individuals highly exposed via their occupations. The final chapter (chapter five) returns to using blow flies as environmental sensors, but this time to detect insensitive munitions in the environment. The work focuses on the development of two different liquid chromatography mass spectrometry methods for the detection of insensitive munitions, which are less shock sensitive explosives, and their transformation products in the environment. Controlled feeding experiments were also performed where flies were exposed to contaminated soil and water sources to show the feasibility of this method in a more realistic scenario. The projects detailed herein show the extensive range with which mass spectrometry can be used for the detection of harmful chemistries of environmental concern.