Application of experimental design for extraction of BHA and BHT from edible vegetable oil and their determination using HPLC

Abstract The optimal conditions of liquid–liquid extraction of two synthetic phenolic antioxidants, BHA and BHT were investigated in five Iranian edible vegetable oil samples using the central composite design. Stepwise multiple linear regression method was used for construction of different models based on the experimental data. Optimum conditions for BHA and BHT were achieved using 3 ml of ethanolic solution containing (0.25% v/v) of glacial acetic acid, three extractions and a mixing time of 10 minutes. Analytes were separated using HPLC with a C 18 column using methanol:water:glacial acetic acid (75:24:1, v/v/v) as the mobile phase. The limit of detections, linear ranges and relative standard deviation () were 0.04 μg/g −1 , 0.5– 200 μg/g −1 and 2.6% for BHA and 0.30 μg/g −1 , 1.0– 200 μg/g −1 and 4.20% for BHT, (), respectively. Amounts of BHA and BHT in analyzed oil samples were in the ranges of 29.8– 54.5 μg/g −1 and 0.0– 6.8 μg/g −1 respectively.