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Effects of temperature on the elimination of benzocaine and acetylated benzocaine residues from the edible fillet of rainbow trout (Oncorhynchus mykiss)

Stehly, G. R., Meinertz, J. R., and Gingerich, W. H., 2000, Effects of temperature on the elimination of benzocaine and acetylated benzocaine residues from the edible fillet of rainbow trout (Oncorhynchus mykiss): Food Additives and Contaminants, v. 17, no. 5, p. 387-392.

Abstract

The effect of temperature (7 ° C and 16 ° C) on the extent of accumulation and the elimination of benzocaine (BNZ) and its metabolite, acetylated benzocaine (AcBNZ), in the fillet tissue of rainbow trout was investigated Residues were measured after bath exposure to an anesthetizing concentration of benzocaine (30 mg/l for 5 min) followed by a maintenance concentration (15 mg/l for 30 min). Immediately after exposure, the BNZ concentration in fillet tissue was approximately 27 µ g/g at both temperatures; AcBNZ was 0.3 µ g/g at 7 ° C and 0.6 µ g/g at 16 ° C. The rates for elimination (α and β) of BNZ and AcBNZ were not significantly different between the two temperatures. Terminal half-lives of elimination for BNZ were 1.62 h at 7 ° C and 1.63 h at 16 ° C; half-lives for AcBNZ were 2.36 h at 7 ° C and 2.77 h at 16 ° C.

Keywords

benzocaine, acetylated benzocaine, edible fillet, rainbow trout, Salmo gairdneri, oxytetracycline, withdrawal, tissue