Field Identification of Unknown Gases and Vapors Via IR Spectroscopy for Homeland Security and Defense

Most chemical detection devices used today by emergency response teams in hazardous gas or vapor events are designed to classify unknowns, at best into broad categories. Consequently, there is a significant demand for precise, sensitive, and broadly-applicable technologies to serve as a primary information resource to identify unknown chemicals in air-monitoring scenarios. Herein, we focus on Fourier transform IR spectroscopy as a highly specific method to identify unknown gases and vapors for homeland security and defense applications. The ruggedized, portable device features a miniaturized Michelson interferometer, a 44-cm path length gas cell, an external sampling interface, and an on-board computer system. Samples are collected with provided hardware and identified by an automated, correlation-based search algorithm that compares unknown spectra to a library of 5500 reference spectra consisting of toxic industrial chemicals and materials, chemical warfare agents, organic solvents, and a variety of other hazardous materials. The hardware and software are designed for use by emergency response teams and military personnel. Details of the system and performance, in addition to how the information is useful particularly in the context of the information provided by other common detection-based devices, are discussed.