Efficient extraction and detection of per- and polyfluoroalkyl substances in honey: A study on extraction mechanism

The efficient extraction of both short- and long-chain per- and polyfluoroalkyl substances (PFAS) from food remains a challenge. However, there are hardly any studies on extraction mechanism in food. This study first confirmed that the protein affinity is the key mechanism affecting efficient extraction of long-chain PFAS from honey by simulating sugaring-out liquid-liquid extraction (SULLE) in the presence of different honey matrix substances. Short-chain PFAS exhibited strong matrix effects under acidic environment of honey. 2% ammonium hydroxide-acetonitrile was used as extraction solvent to effectively releases the binding of PFAS-proteins and minimize matrices interference. By combining liquid chromatography-tandem mass spectrometry, a novel method for the determination of 22 PFAS from honey was developed, which showed low limit of quantification, satisfactory accuracy and precision. This work not only provides a highly-efficient and cost-effective approach for analyzing PFAS in honey, but also offers deep insights into the efficient extraction of PFAS from food.