Enantiomer- and isomer-specific fate of persistent organic pollutants in the environment

• Author / Creator

  Ross, Matthew Stephen

• This thesis discusses the fate of individual enantiomers and isomers of organohalogen compounds (OHCs) in the environment and the development of analytical methods to facilitate such determinations.
  A novel proof of principle anion attachment atmospheric pressure photoionization (AA-APPI) method was developed. Minimal matrix effects, increased sensitivity and lower limits of detection were found in sediment extracts spiked with hexabromocyclododecane (HBCD) compared to atmospheric pressure photoionization. AA-APPI offers a simple means of further extending the range of compounds ionizable by photoionization, while maintaining minimal matrix effects.
  Enantiomer fractions (EFs) of chiral OHCs were determined in the blood and eggs of glaucous gulls from Svalbard, Norway, to determine the enantioselectivity of OHC maternal transfer. No differences were found between the EFs for any analyte in female gulls compared to those found in egg yolk. This indicates that processes involved in the maternal transfer of OHCs to eggs do not modulate the stereochemical ratio between enantiomers.
  
  EFs of polychlorinated biphenyl (PCB) atropisomers were determined in the sediment and biota from an estuary heavily contaminated with highly chlorinated PCB congeners. Non-racemic EFs were found in sediment, likely the result of microbial dechlorination. EFs in grass shrimp mirrored those of sediment, but non-racemic EFs in fish species and bottlenose dolphins were likely a result of both uptake of non-racemic proportions of PCBs from the diet and enantioselective biotransformation.
  OHC EFs were investigated in captive sledge dogs fed OHC-polluted minke whale blubber, to gain greater understanding of the biotransformation capacity of a model polar bear surrogate species. Sledge dogs biotransformed OHCs enantioselectively, and the comparative enantiomer-specific biotransformation capacity showed similar and contrasting results based on individual compounds/congeners.
  The isomer-specific fate of perfluorooctane sulfonamide (PFOSA) was investigated in male Sprague-Dawley rats. PFOSA elimination occurred isomer-specifically, resulting in a depletion of branched PFOSA isomers in blood. Isomer-specific formation of PFOS was also observed. The significant enrichment of 5m-PFOS and the depletion of the alpha branched PFOS isomer provide the first in vivo evidence that exposure to PFOS precursor compounds alters the isomer pattern of PFOS in biota.

• Subjects / Keywords

  • Polychlorinated biphenyls
  • Persistent organic pollutants
  • Perfluorooctane sulfonate

• Graduation date

  Spring 2011

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3C12C

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.