Determination of 2,6-Di-tert-Butyl-4-Hydroxytoluene (BHT): Application to Edible Fats and Oils BHT is a very effective antioxidant for many organic substances such as edible fats and oils. Its wide use either alone or in combination with other antioxidants has indicated a need for a specific and effective method for its quantitative determination to maintain effective control over processing operations and to ensure adherence to regulatory requirements. The method presented is based on separation of BHT from fat or oil by steam distillation and colorimetric determination with a dianisidine-nitrous acid reagent.The method is capable of determining 10 to 200 p.p.m. BHT in the presence of other allowable antioxidants.