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Scott T. Porcher

Publications and source records attributed to Scott T. Porcher.

3 recordsLinked to original sources

Evaluation of a method for quantifying eugenol concentrations in the fillet tissue from freshwater fish species

AQUI-S 20E ® (active ingredient, eugenol; AQUI-S New Zealand Ltd, Lower Hutt, New Zealand) is being pursued for approval as an immediate-release sedative in the United States. A validated method to quantify the primary residue (the marker residue) in fillet tissue from AQUI-S 20E–exposed fish was needed. A method was evaluated for determining concentrations of the AQUI-S 20E marker residue, eugenol, in freshwater fish fillet tissue. Method accuracies from fillet tissue fortified at nominal concentrations of 0.15, 1, and 60 μg/g from six fish species ranged from 88–102%. Within-day and between-day method precisions (% CV) from the fortified tissue were ≤8.4% CV. There were no coextracted compounds from the control fillet tissue of seven fish species that interfered with eugenol analyses. Six compounds used as aquaculture drugs did not interfere with eugenol analyses. The lower limit of quantitation (LLOQ) was 0.012 μg/g. The method was robust, i.e., in most cases, minor changes to the method did not impact method performance. Eugenol was stable in acetonitrile–water (3 + 7, v/v) for at least 14 days, in fillet tissue extracts for 4 days, and in fillet tissue stored at ~ −80°C for at least 84 days.

Journal of AOAC International

Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout ( Oncorhynchus mykiss ) skin-on fillet tissue

Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximize anaesthetic/sedative residue concentrations in rainbow trout ( Oncorhynchus mykiss ) skin-on fillet tissue. Rainbow trout (167–404 g) were exposed to 50 mg l −1 AQUI-S® 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l −1 AQUI-S® 20E for durations up to 240 min, and 500 and 1000 mg l −1 AQUI-S® 20E for durations up to 90 min. Fish exposed to 100 mg l −1 AQUI-S® 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g −1 , respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all < 39 µg g −1 .

Food Additives & Contaminants: Part A

Depletion of eugenol residues from the skin-on fillet tissue of rainbow trout exposed to 14C-labeled eugenol

The U.S. is lagging in access to an approved immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and has no withdrawal period. AQUI-S® 20E (10% active ingredient, eugenol) is under investigation as an immediate-release sedative for freshwater finfish. Because of its investigational status, data are needed to characterize the depletion, distribution, and identity of AQUI-S® 20E residues in fillet tissue. Rainbow trout ( Oncorhynchus mykiss ) were exposed to uniformly ring labeled 14 C-eugenol at a nominal concentration of 10 mg/L for 60 min in 18 °C water. Fish (n = 6) were sampled immediately after the exposure (0 min) then at 30, 60, 120, and 240 min. Eugenol concentrations and characterization of 14 C residues in the fillet tissue were determined by high pressure liquid chromatography and flow-through liquid scintillation counting techniques. Total 14 C-residue burdens in fillet tissue were determined by tissue oxidation and static liquid scintillation counting techniques. Maximum eugenol and 14 C-eugenol equivalent residue concentrations in the fillet tissue were measured immediately after the exposure (44.5 and 38.8 μg/g, respectively). Eugenol was the primary 14 C-residue (> 90% of all 14 C-residues) in extracts from fillet tissue taken from fish sampled immediately after the exposure (0 min) and from fish sampled at 30 and 60 min after the exposure. The depletion of 14 C-eugenol residues from the fillet tissue was rapid (t 1/2 = 26.25 min) after transferring the exposed fish to fresh flowing water.

Aquaculture