Discovery of Emerging Disinfection By-Products in Water Using Gas Chromatography Coupled with Orbitrap-based Mass Spectrometry

[Orbitrap_SciLib]

Cojocariu C, Postigo C, Richardson SD, Barcelo D, and Silcock P.
Application Note 10490
This work has shown the successful application of the Q Exactive GC system for the characterization of iodo-DBPs in disinfected water extracts. • A large number of peaks were detected in the samples analyzed and an exact mass filter in TraceFinder was used to isolate only the compounds containing iodine. Higher concentrations of iodo-DBP were found in the samples exposed to chloramination compared to chlorination treatments. • The EI data obtained can be used for candidate compound identification against existing commercial libraries. Importantly, as often the chemicals detected are not included in such libraries, the consistent sub-ppm mass accuracy measurements will unambiguously determine the elemental composition and subsequent structural elucidation of unknown chemicals. • Moreover, softer ionization such as positive chemical ionization with methane can be used to confirm the elemental composition of the molecular ion of a chemical. • The Q Exactive GC mass spectrometer and the compound discovery and identification workflow described here allow for rapid detection and confident identification of unknown DBPs in disinfected water, enabling researchers to reliably and timely report the identities of the unknown chemicals.


Thermo Fisher Scientific, Institute of Environmental Assessment and Water Research, University of South Carolina, and Catalan Institute for Water Research.