Suspect screening of human serum with UHPLC-QTOF/MS

Abstract: The number of environmental pollutants has increased due to the increased production and the use of various chemicals in different applications. An estimation of today’s synthetic chemicals is approximately 50,000 to 100,000 and many of them may be harmful to humans and the environment. Persistent Organic Pollutants (POPs) are a specific type of environmental pollutants that are very stable and do not decompose easily. Example of those are pesticides, phthalates, phenols and per-/polyfluorinated alkyl substances (PFASs). Several studies have reported that environmental pollutants may particularly affect pregnant women and the fetus. The aim of the present study was to characterize the environmental pollutant profile in serum extracts of pregnant women, by analyzing the blood and characterizing the chemicals using a suspect screening approach with chromatography combined with high-resolution mass spectrometry. The samples in this study were extracted with solid-phase extraction (SPE) prior to the instrumental analysis, to precipitate the proteins as well as to remove some phospholipids and other contaminants that could interfere with the instrumental analysis. Quality control samples was used to validate the instrumental performance. Twelve compounds out of the 38 suspects were identified with this method, including both fatty acids and a few environmental pollutants. The detection rate of the fatty acids was higher than the environmental pollutants, which are; perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), monooctyl phthalate and 3,5-ditertbutyl salicylic acid. The low detection rate of the environmental pollutants, particularly of PFASs could be due to the low sensitivity of the method for the PFASs but also due to the decreased exposure to those compounds, since the samples were collected between 2013 to 2016, after the restrictions in the use of the two most common PFASs; PFOA and PFOS.