Simultaneous GC-FT-IR/GC-MS Analysis for Isomer-Specific Identification and Quantitation of Complex Mixture Components

Abstract

The construction and capabilities of a new instrument combining infrared and mass spectrometry to simultaneously examine the effluent from a single capillary column gas chromatographic injection are described. Gas chromatography-mass spectrometry (GC-MS) is performed in the conventional manner. However, the Fourier transform infrared (FT-IR) portion of the instrument employs a new sampling method involving low-temperature trapping of the effluent from the gas chromatograph. The mass spectrometer was over two orders of magnitude more sensitive (161 fg detection limit for naphthalene) than the infrared (40 pg). The qualitative capabilities of infrared spectrometry, particularly when isomerspecific identifications are necessary, are shown to be highly complementary to the usual GC-MS method for analyzing complex mixtures