Accurate mass screening and identification of emerging contaminants in environmental samples by liquid chromatography-LTQ FT Orbitrap mass spectrometry

The European REACH legislation will possibly drive producers to innovate their products, possibly to develop newly designed chemicals that will be less persistent, bioaccumulative or toxic. If this innovation leads tot an increased use of more hydrophilic chemicals - that are generally less persistent, bioaccumulative or toxic - this may result in higher mobilities of chemical in the aqueous environment. As a result, the drinking water companies may face stronger demands on removal processes as the hydrophilic compounds inherently are more difficult to remove. Monitoring efforts will also experience a shift in focus to more water-soluble compounds. Screening source waters (groundwater, surface water) on the presence of emerging) contaminants is an essential step in the control of the water cycle from source to tap water. In this article, some of our experiences are presented with the hybrid linear ion trap (LTQ) FT Orbitrap mass spectrometer, in the area of chemical water analysis. A two-pronged strategy in mass spectrometric research was employed: (i) exploring surface, ground- and drinking water samples searching for accurate masses corresponding to target compounds (and their product ions) known from e.g. priority lists or the scientific literature and (ii) full-scan screening of water samples in search of ‘unknown’ or unexpected masses, followed by MSn experiments to elucidate the structure of the unknowns. Applications of both approaches to emerging water contaminants are presented and discussed. The applications of accurate mass screening and identification described in this article demonstrate that the LC-LTQ FT Orbitrap MS is well equipped to meet the challenges posed by newly emerging polar contaminants.