EFFECTS OF MODE OF STERILIZATION ON THE RECOVERY OF PHENOLIC ANTIOXIDANTS IN LABORATORY MEDIA ASSESSED BY NONDERIVATIZING GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

The effects of autoclaving and filter sterilization on the recovery of butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhyd roquinone, and propyl gallate in laboratory media were investigated by a nonderivatizing gas chromatography-mass spectrometry (GC-MS) method . Lauryl tryptose broth (LTB) or brain heart infusion (BHI) broth were treated with the combinations of the phenolic antioxidants at 200 ppm . The antioxidants were dissolved in 95% ethanol and either added dire ctly to the media followed by autoclaving or filter-sterilized and the n added to sterilized media in a flask. Results suggested that antioxi dant recoveries were affected by the modes of sterilization as well as by the complexity of the medium. More antioxidants were recovered fro m the filter-sterilized than from the autoclave-sterilized samples for LTB medium, but no clear difference was seen for BHI broth. The recov ery was lowest with butylated hydroxytoluene regardless of medium type or sterilization mode used. The extraction procedure applied as well as the nonderivatizing GC-MS method appeared to be adequate for the si multaneous determination of the four antioxidants.