Determination of 4,4'-Difluorobenzophenone and Hydroquinone in PEEK Plastics by Ultra Performance Liquid Chromatography.

A method for the determination of the migration of 4, 4'-difluorobenzophenone and hydroquinone in PEEK food contact materials by ultra performance liquid chromatography was established. The samples were soaked in six food simulants. Water, 4% acetic acid, 10% ethanol and 20% ethanol food simulants were directly filtered and injected. The 50% ethanol and 95% ethanol food simulants were concentrated by rotary evaporation, dissolved in water and diluted, and the solution was filtered and injected. The separation was achieved within 7 min by C18 column and acetonitrile-water mobile phase gradient elution. The mass concentration of 4,4'-difluorobenzophenone in six food simulants is linear with the peak area in range of 0.025~0.500 mg/L, and the lower limit of quantification is 0.012~0.020 mg/kg. The mass concentration of hydroquinone has a linear relationship with its peak area in range of 0.1~2.0 mg/L, and the lower limit of quantification was in range of 0.050~0.072 mg/kg. The recoveries at three concentration levels were in the range of 92.5%~109%. The relative standard deviations (RSDs, n=6) were in range of 3.0%~7.6%. The method has been applied to the determination of the migration of 4,4'-difluorobenzophenone and hydroquinone in PEEK plastics for food contact. [ABSTRACT FROM AUTHOR]