Analysis of Perfluorinated Compounds: comparison between Liquid Chromatography coupled to Tandem Mass Spectrometry and High Resolution Mass Spectrometry

Perfluorinated compounds, described by some scientist as the “PCBs of the twenty-first century”, are a group of contaminants which present bioaccumulative and persistent properties. Significant amounts of these compounds were detected in human blood and in the liver of many species, and it appears that a potential risk could exist for developmental and other adverse effects associated with exposure in humans. Due to the high affinity of these compounds with the proteins, milk appears to be a highly exposed matrix. Contamination could be present naturally (transfer from cow to milk) or during the processing of milk. The potential toxicity of this matrix is of high concern, considering the large amounts of milk consumed by children. A sensitive and specific method has to be used in order to quantify accurately these compounds in cow milk. Extraction and purification processes present major problems due to the high complexity of the matrix, and they have been optimized using different protocols. A detection method by liquid chromatography coupled to tandem mass spectrometry has been developed, which enables the quantification of 15 perfluorinated compounds, especially PFOS and PFOA. The advantages of using a high resolution system are described in terms of sensitivity and specificity.