Determination of five phenolic antioxidants in edible oils: Method validation and estimation of measurement uncertainty

An analytical protocol and the measurement uncertainty for determination of butylated hydroxylanisole, butylated hydroxyltoluene propyl gallate, octyl gallate and dodecyl gallate in edible oils were reported. Details of the validation including application of certified reference materials and participation in proficiency tests were discussed. Traceability of measurement was established through traceable standards and calibrated volumetric equipment and measuring instruments. The protocol, comprising a TLC screening step, quantification by gas chromatography-flame ionization detection (GC-FID) and high performance liquid chromatography-photodiode array detection (HPLC-PDA) techniques, and unequivocal confirmation by mass spectrometry or a second chromatographic technique, provides a reliable and validated means for fast turnaround and high sample throughput analysis of the five antioxidants in edible oils. This protocol was also found to be applicable to other fat-containing food matrices.