Withdrawal time for sulfamethoxazole and trimethoprim following treatment of striped catfish (Pangasianodon hypophthalmus) and hybrid red tilapia (Oreochromis mossambicus × Oreochromis niloticus)

In conclusion, the validated LC-MS/MS combined with Agilent Bond Elut QuEChERS extraction performed well for the analysis of SMX and TMP and is recommended for routine analysis in striped catfish muscle. A withdrawal time of 15 days for striped catfish and three days for red tilapia treated with TMP and SMX is sufficient to meet the EU MRLs for fish intended for human consumption.