A rapid and simple fluorometric method for quantifying isoeugenol in seawater and in plasma and white muscle from Australasian snapper (Pagrus auratus)

Isoeugenol residues in Australasian snapper (Pagrus auratus) white muscle, blood plasma and seawater were accurately and precisely quantified after extraction with acetonitrile using fluorometric detection (ex. 260 nm, em. 340 nm) without chromatographic separation. Isoeugenol residues in Australasian snapper (P. auratus) muscle tissue following 30 min exposure to 58.2 μmol L⁻¹ isoeugenol (ca. 20 ppm of the aquatic anaesthetic AQUI-S™) reached a maximum of 134.37 ± 8.13 μmol kg⁻¹ (±SEM; n = 6). Blood plasma isoeugenol concentrations following this harvesting regime were 253.2 ± 25.1 μmol L⁻¹. After 7 h recovery, fillet isoeugenol residues reduced to 7.89 ± 1.67 μmol kg⁻¹. Storage of fillets from fish harvested with AQUI-S™ at 3.87 ± 0.54 °C for 5 days resulted in a rate of isoeugenol decay in the fillets of 6.51 ± 1.19 μmol kg⁻¹ day⁻¹. The method reported can be used for measuring isoeugenol residues in food products or to further study the physiological and biological effects of isoeugenol in fish.