Replacement of Recommended Practices Ce3-74 and Ce7-87 with a Single Method for Analysis of Tocopherols and Sterols in Deodorizer Distillates and Other Related Matrices by Gas Chromatography

This method was created to replace antiquated AOCS recommended practices Ce3-74 (Tocopherols and Sterols in Soy Sludges and Residues) and Ce7-87 (Total Tocopherols in DOD) with a modern method for analysis of both tocopherols and sterols in distillate samples. Alpha tocopherol and stigmasterol standards are used as response factor standards for tocopherols and sterols. Samples are weighed, diluted in pyridine using a betulin internal standard, and derivatized using BSTFA with 1 % TMCS. Samples are analyzed on a 15 m DB-5HT column with 0.25 mm inner diameter and 0.1 micron film thickness using hydrogen gas carrier under constant velocity. A variety of distillate products were analyzed to identify and eliminate potential coelution. Tocopherols, sterols, squalane, squalene, tocopherol acetates, and tocotrienols were resolved while maintaining an efficient run time. The improved method provides a single 30 minute analysis of all analytes providing greater resolution through the use of a shorter, smaller inner diameter column which allows removal of time consuming and unnecessary preparation procedures.