Antioxidants in some pharmaceuticals, cosmetics and food from the European market.

A specific and sensitive reverse phase HPLC method (AO-1) for the quantitative determination of ten phenolic antioxidants and propyl paraben in fatty products (food, pharmaceuticals and cosmetics) has been developed. Extraction with acetonitrile from a hexane dilution of the products; acetic acid-water-acetonitrile-methanol solvent system and detection at 280 nm and quantification by internal standard procedure (reference compound: DMP, dimethylphenol) were used. Good resolutions for all peaks, especially BHT and DG, and no interferences with others common additives were achieved. Mean recoveries, by addition of standards to sample at 20, 50 and 100 micrograms/g, were 96-101% (BHT, 84-86%); minimal quantifiable levels were 0.5-1.6 micrograms/g. Two simple isocratic methods for the confirmation of data obtained by AO-1 were also developed: AO-2 for seven phenolic antioxidants and propyl paraben with DMP as internal standard, AO-3 for four lipophilic antioxidants with di-tert-butylphenol (DTBP) as internal standard.