The Measurement of On-The-Fly Fourier Transform Infrared Reference Spectra of Environmentally Important Compounds

The United States Environmental Protection Agency (U.S. EPA) requires reference spectra to support its gas chromatography/Fourier transform infrared (GC/FT-IR) routine environmental monitoring program. Although on-the-fly (OTF) techniques are needed to satisfy the Agency's high sample throughput requirements, the FT-IR vapor-phase reference spectra produced by the Agency thus far have been measured under static conditions. Accordingly, the OTF spectra of 47 environmentally important compounds have been measured by packed-column GC/FT-IR under carefully controlled conditions. The compounds selected for spectral measurement are currently regulated by the U.S. EPA and generally represent compound classes which are absent, or poorly represented, in the current U.S. EPA data base (e.g., organochlorine and organophosphorus pesticides). Where feasible, the Co-blentz Society guidelines for the measurement and recording of vapor-phase infrared reference spectra and supporting data were followed. The sensitivity order of the reference compounds as determined by the strongest spectral band and the quantity of compound injected on-column was, organophosphorus and thio-organophosphorous > aliphatic organochlorine ≥ polynuclear aromatic.