The infrared spectra of mono-, di-, and triglycerides

Summary The infrared spectra from 2 to 12 microns of chloroform ( solutions of several glycerides have been measured and studied with a view to possible analytical applications. These spectra are presented, and conclusions which can be obtained from their examination are reported in this paper. The principal bands, common to the spectra of all glycerides, have been tabulated with correlations of the vibrating groups which give rise to them. The analytical significance of the infrared spectra is considered in detail for three specific regions: a) the O−H stretching vibration region, about 3.0 microus; b) the C−O stretching vibration region, about 9.0 microns; and c) the 10.0-micron region of C−H bending, about the C=C group. Analyses of these regions of the spectra indicate that infrared absorption can be used to detect and to determine mono-, di, and triglycerides in admixtures and that the method for the determination of transisomers can, with modifications, be extended to include analysis of triglycerides. Presented at the 45th annual meeting of the American Oil Chemists' Society, San Antonio, Tex., April 11–14, 1954. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.