Quantitative analysis of malachite green and leucomalachite green residues in fish purchased from the markets in Malaysia

Malachite green (MG) is still being used as an antiparasitic and antifungal agent in aquaculture. This is due to the fact that many stakeholders are not aware of the potential genotoxic and carcinogenic properties of MG. Since the consumption of fish in Malaysia was recorded to be the highest in Southeast Asia in 2013, it is therefore important to ensure that fish sold in the market are free of MG and its metabolite, leucomalachite green (LMG). In this study, MG and LMG residues in muscle tissue of commonly consumed fish such as red tilapia (Oreochromis hybrid), African catfish (Clarias gariepinus), barramundi (Lates calcarifer), hybrid grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) and striped catfish (Pangasius hypophthalmus) were analysed using liquid chromatography-tandem mass spectrometry. The fish were purchased from 11 different markets in the state of Selangor, Malaysia. The results showed that the sum residues of MG and LMG in the present study ranged from 0.53 to 4.10 μg/kg with the highest residue detected in domestic striped catfish. This study indicates that MG is still being used and aquaculture stakeholders should be made aware of the judicious use of MG for the benefit of public health.