Discovery of Emerging Halogenated Contaminants of Concern in Great Lakes Lake Trout

Session: Chemical Monitoring and Surveillance in the Great Lakes: Multimedia (1)

Sadjad Fakouri Baygi, Clarkson University, [email protected]
Sujan Fernando, Clarkson University, [email protected]
Philip Hopke, Clarkson University, [email protected]
Thomas Holsen, Dept. Civil & Environ. Eng., Clarkson University, [email protected]
Bernard Crimmins, Clarkson University, [email protected]

Abstract

Halogenated contaminants are typically the largest fraction of persistent, bioaccumulative and/or toxic (PBT) chemicals in the Great Lakes. Legacy halogenated contaminants (e.g. PCBs) have been monitored, but many additional halogenated compounds may still be undiscovered. To understand the impact of unknown PBT halogenated chemicals in Great Lakes, top predator fish (trout) were analyzed using an atmospheric pressure gas chromatographic (APGC) coupled with quadrupole time-of-flight (QToF) instrument that produces soft ionization full scan high-resolution mass spectrometer (HRMS) data. An Isotopic Profile Deconvoluted Chromatogram (IPDC) algorithm was developed to screen for halogenated compounds using the distinct identifiable mass spectral signatures in HRMS data. The IPDC algorithm was equipped with several data reduction techniques including a false positive prediction by a neural network, a mass defect filter, a boiling point prediction, and a ranking system for candidate molecular formula. The IPDC algorithm detected approximately 202 features associated with legacy contaminants in Lake Michigan Lake Trout collected in 2016 sample and produced a list of 228 unknown isotopic features for future investigations. A temporal trend of the uncategorized halogenated futures was produced to compare between sites years (2005/2006 vs. 2015/2016) to determine the spatiotemporal impact of halogenated and potential PBT compounds in Great Lakes.

Twitter handle of presenter
@FakouriRyan