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Using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, collaborating scientists in ten different laboratories measured (in duplicate) the total trans fat content of ten fat or oil test samples, two of which were blind duplicates. The procedure used entailed measuring the height of the negative second derivative of the IR absorption band at 966 cm -1 . This absorption is attributed to the C-H deformation vibration that is characteristic of isolated (non-conjugated) double bonds with the trans configuration. The precision of ATR-FTIR results in this international collaborative study was satisfactory and led to the approval of this validated procedure as official method AOCS Cd 14e-09 in late 2009. This official method is also suitable for analysis of total isolated trans fat and oil products containing, or supplemented with, trans conjugated linoleic acid (CLA) isomers. Although this method does not require derivatization of the oil or fat test materials, as required for GC, fats and oils in foods must be extracted with organic solvents before analysis. This method is also rapid (5 min) and does not require any weighing or quantitative dilution of unknown neat fat or oil test samples in any solvent. The AOCS Cd 14e-09 method is suitable for determination of test samples with zero trans fat, which is defined according to the US labeling regulations as 0.5 g trans fat per serving or 1.8% trans fat, as a percentage of total fat.

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AOCS Official Method Ce 6-86 “Antioxidants, Liquid Chromatographic Method” was originally developed to confirm the correct antioxidant was added at the specified concentration to refined oils. Today, this method is increasingly utilized to validate that antioxidants are absent from oil products. False positive results can have a significant impact on the ability to sell products in specific markets and can impart additional business expenditures for conclusive secondary analyses. In the current work, quantification of tert-butylhydroquinone (TBHQ) in crude canola/rapeseed oil using liquid chromatography (LC) with ultraviolet (UV) detection was compromised by an interfering peak. Analyses using liquid chromatography-mass spectrometry (GC–MS) and high-resolution accurate mass LC–MS identified the interferent as 2,6-dimethoxy-4-vinylphenol (canolol), an endogenous compound present in crude canola/rapeseed oil. Resolution of canolol and TBHQ using LC-UV can be achieved via minor modification of the chromatographic conditions.