19F-NMR and directly coupled 19F/1H-HPLC-NMR spectroscopic investigations of the metabolism of the model ecotoxin 3-trifluoromethylaniline in the earthworm species Eisenia veneta.

ABSTRACT

1. The metabolic fate of the model ecotoxin 3-trifluoromethylaniline (3-TFMA) in earthworm was studied by (19)F- and directly coupled (19)F/(1)H-HPLC-NMR spectroscopy. Earthworms of Eisenia veneta spp. were subjected to the ecotoxin during a filter papercontact toxicity test at exposure levels of 1000, 100, 10, 1 and 0.1 micro g cm(-2). A metabolic profile was obtained previously by (19)F-NMR spectroscopy and metabolites were observed at all the exposure levels. 2. Identification of metabolites in individual worm extracts at the (lethal) exposure levels of 1000 and 100 micro g cm(-2) could be achieved on-line without sample preparation by (19)F/(1)H-HPLC-NMR spectroscopy. (19)F-HPLC-NMR spectroscopy was used in the continuous-flow mode, which enabled the HPLC chromatographic retention times (t(R)) of the metabolites to be established in a single analytical step. 3. In total, three (19)F-NMR signals could be detected, of which one was identified as the parent compound. Two earlier eluting metabolites were identified to be alpha- and beta-glucoside conjugates of 3-TFMA. 4. Metabolites at the lower (sublethal) exposure levels of 10, 1 and 0.1 micro g cm(-2) escaped identification by (19)F/(1)H-HPLC-NMR spectroscopy as outlined here and will require concentration prior to analysis.