Triaclyglycerides (TAGs), which form the bulk of vegetable and animal oils, are subject to polymerization reactions when heated. These reactions occur by thermal polymerization1 or by oxidative polymerization reaction via radicals. These polymeric compounds create high-boiling point, higher viscosity,2,3 and insoluble materials, which can affect product quality and properties. For cooking, these polymerized triglycerides (PTGs) can result in increased oil absorption into cooked foods,4 gumming of the fry bath, and possibly unhealthful conditions such as reduced digestibility.5

　　The current method for the determination of these PTGs is by HPLC with size exclusion chromatography (SEC) and refractive index (RI) detection, which also requires a solid phase extraction (SPE) process to remove these polymers from the TAGs.6 A reverse phase HPLC method was developed, using a C18 column and gradient elution chromatography using the Thermo Scientific™ Dionex™ Corona™ Veo™ Charged Aerosol Detector. This method has several advantages: no SPE is required, as the TAGs do not interfere with the analysis of the PTGs, the chromatography provides more information in the equivalent time, and the detector is highly sensitive and precise, thereby improving data quality.