Refined and bleached fats and oils can be analyzed directly by high‐temperature glass capillary column gas chromatography after derivatization of the fatty acids, mono‐ and diglycerides with BSTFA [(N,O)‐bis(trimethyl silyl) trifluoroacetamide]. The intact glycerides are separated on the basis of volatility to provide characteristic carbon number profiles (CNP). Quantitative information on mono‐, di‐ and triglycerides, as well as free fatty acids, is obtained from a single, rapid separation. Profile values are reported for 13 different processed fats and oils. The analysis performed in the split‐injection mode maintains column integrity after numerous separations, while producing acceptable relative standard deviations.

Two basic gas chromatographic approaches are currently used for the analysis and characterization of processed soy oil and other lipid materials. One approach separates the intact glycerides after silylation whereas the complementary approach determines the fatty acid composition of the glycerides by the formation and subsequent separation of the corresponding fatty acid methyl esters. A brief history of the development of these gas chromatographic procedures and a more detailed discussion of current packed and capillary column technology used for the separation of both intact glycerides and fatty acid methyl esters is presented. Emphasis is placed on the advantages of the newly emerging capillary techniques over the more conventional packed column separations. High resolution chromatograms are shown for the separation of mixed glyceride isomers and also for the separation of unsaturated methyl esters with respect to the number, geometry and position of the double bonds. The separation of the methyl esters can provide information equivalent to classicalcis,cis‐lipoxygenase, iodine monochloride titration and infraredrans analyses. Finally, the use of short capillary columns to achieve rapid low cost separations (with resolution equivalent to packed column separations), ideal for quality control, also are discussed.

A new method is described for the determination of caffeine in coffee, based on high-pressure liquid chromatography. The caffeine is extracted from the sample with water and/or methylene chloride, and then separated from interfering materials by passing an aliquot of the extract through a high-pressure column containing sulfonated cation exchange resin, using 0.01M nitric acid as the mobile phase. An ultraviolet detector measures the absorption of the solution directly. The method is rapid and eliminates the lengthy separations common to other methods. The procedure was applied successfully to decaffeinated and non-decaffeinated green, roasted, and instant coffees. This method gives a more accurate measure of the caffeine content in decaffeinated coffee samples than the micro Bailey-Andrew and modified Levine methods, with equal or better precision. This method gives results equal to those obtained by the official methods for non-decaffeinated samples.