Gas chromatography‐fourier transform infrared spectrometry of fatty acids: New applications with a direct deposition interface

Infrared spectroscopy is a suitable spectroscopic method to differentiate geometric Z and E isomers of unsaturated compounds. A direct‐deposition Fourier transform infrared spectrometer (FTIR), coupled to a gas chromatograph, was used successfully to analyze with a high sensitivity traces of C18:1 fatty acid methyl ester (FAME) isomers. It could also conclusively distinguish between isomers of conjugated diunsaturated FAME. The achievable sensitivity of this direct‐deposition device makes possible accurate FAME mixture analyses that are not currently attainable with the more conventional light‐pipe interface.