Residual levels and risk assessment of eugenol and its isomers in fish from China markets

Levels of eugenol, isoeugenol and methyleugenol were investigated in 216 seawater fish and 321 freshwater fish from wholesale markets. Eugenol was detected in 55 samples with concentrations ranging from 3.11 to 30,690μg/kg. Isoeugenol was detected only in two samples of grouper at concentrations of 1032μg/kg and 86.2μg/kg. Methyleugenol was not detected in any samples. The incidence of anesthetic residue in all the samples was 10.6%. The frequencies of species found with anesthetic residue were higher in seawater fish than in freshwater fish, with rates of 19.4% and 4.7%, respectively. The warm seawater fish such as grouper, sea bass, sea bream, pompano, and red drum should be monitored more closely in the future due to the higher detection frequencies and values of these compounds. Although the results indicate that eugenol or isoeugenol have been used as fish anesthetic to assist with fish handling and fish transport in some species, the human health risk is negligible.