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Accurate Structural Assignment Tool for PCBs Congeners, Using GCxGC (front-end) and Mass Spectrometric Ortho-Effects
Citation:
Osemwengie, L. Accurate Structural Assignment Tool for PCBs Congeners, Using GCxGC (front-end) and Mass Spectrometric Ortho-Effects. 2021 SETAC North America Annual Meeting, Virtual, November 14 - 18, 2021.
Impact/Purpose:
This study evaluates the use of comprehensive two-dimensional gas chromatography (2D-GC) coupled with a time-of-flight (TOF) mass spectrometer for the separation of 209 PCB congeners, using a sequence of 1D and 2D chromatographic modes. Some of the chlorinated biphenyls that could not be resolved chromatographically are resolved with the use of mass spectrometric “ortho effect,” which distinguishes PCB isomers having 2,2’-; and 2,2’6- chlorine substitution from those isomers without these substitutions. Commercially available standards permitted the test of all 209 PCB congeners for the mass spectrometric “ortho effect,” or the enhancement of the [M-Cl]+ ion abundance, relative to the molecular ion for biphenyls having 2,2'-; 2,2',6-; and to a smaller degree, 2,2',6,6'- chlorine substitution. Using chromatographic evidence, this study verified that much smaller “ortho effects” were observed for PCBs lacking any, or one ortho chlorine (2-), or two ortho chlorines on the same ring (2,6-). The result of this work potentially provides investigators with a combined new tool for a better front-end (GC column) and mass spectrometric separations of PCB-specific congeners, optimized for the acquisition of more accurate data.
Description:
Accurate Structural Assignment Tool for PCBs Congeners, Using GCxGC (front-end) and Mass Spectrometric Ortho-Effects. The method using Gas Chromatographic and Mass Spectrometric ortho-effects, has been described on the impact statement
