Molecular Spectroscopy: Underutilized Detection for Gas Chromatography

Molecular spectroscopy techniques, most commonly ultraviolet-visible (UV-vis), are usually thought of as analyzing liquid-phase samples, with techniques such as high-performance liquid chromatography (HPLC). Although not as common as in HPLC, molecular spectroscopy can be used with gas chromatography (GC) as well. In this installment, we examine molecular spectroscopy in combination with GC. The two most common techniques used with GC today are Fourier transform infrared spectrometry (FT-IR) and vacuum ultraviolet spectroscopy (VUV). Both provide structural and quantitative information and can be used in complementary fashion with the more common GC–mass spectrometry (GC–MS) and classical detectors. We will discuss the basics of GC–FT-IR and GC–VUV, when and when not to use them, and how they compare to and complement classical detectors.