Simultaneous Determination of Five Synthetic Antioxidants in Fats and Oils

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of gallic acid n-propyl ester (PG), tert-butyl hydroquinone (TBHQ), nor-dihydroquaiaretic acid (NDGA), 3-tert-butyl-4-hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in fats and oils was developed. The samples were dissolved in n-pentane. Aliquot (1 ml) of the pentane solutions was pipetted onto Adsordex RP-18 extraction column (400 mg). The antioxidants were eluted with three 1-ml portions of acetonitrile/2-propanol (1:1). The filtrate and the eluate were collected and mixed. The final volume was adjusted to 4 ml with acetonitrile/2-propanol and determined by HPLC with a UV detector set at 280 nm. The recoveries of PG, TBHQ, NDGA, BHA and BHT fortified to various edible fats and oils were in the range of 92.0--98.1 %, 92.2--99.9%, 98.8--100.7%, 90.5--97.1% and 91.0--97.0%, respectively. Each of the standard and calibration curves for PG, TBHQ, NDGA, BHA and BHT showed a good linear relationship in the range of 2.5--20 ppm.