Jeffry A. Bernardy

Liquid chromatographic determination of benzocaine and N-acetylbenzocaine in the edible fillet tissue from rainbow trout

A method was developed for determining benzocaine and N-acetylbenzocaine concentrations in fillet tissue of rainbow trout. The method involves extracting the analytes with acetonitrile, removing lipids or hydrophobic compounds from the extract with hexane, and providing additional clean-up with solid-phase extraction techniques. Analyte concentrations are determined using reversed-phase high-performance liquid chromatographic techniques with an isocratic mobile phase and UV detection. The accuracy (range, 92 to 121%), precision (R.S.D., < 14%), and sensitivity (method quantitation limit, < 24 ng/g) for each analyte indicate the usefulness of this method for studies characterizing the depletion of benzocaine residues from fish exposed to benzocaine.

Uptake, Metabolism, and Elimination of TFM by Fish

The larval lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used to control sea lamprey (Petromyzon marinus) in the Great Lakes basin for over 30 years. Studies have been conducted to (1) determine the nature and magnitude of TFM and TFM residues in fish fillet tissue under acute exposure conditions, and (2) determine the rates of uptake, elimination, and the nature and magnitude of TFM and TFM residues in fish tissues under subchronic exposure conditions. Data from these studies were submitted to the U.S. Environmental Protection Agency to support the reregistration of TFM. An historical perspective on the sea lamprey control program, data from previous research on the nature of TFM residues in fish, and the results of the studies conducted at UMESC are presented.