Representative chromatograms of a standard MG solution (10 ng/ml), a blank sample of rainbow trout muscle, and a spiked blank sample with MG þ LMG (2 mg/kg) are shown in Fig. 1. It is evident that no interfering peaks from endogenous components were detected near the retention time of MG. This indicates the specificity of the method for analysis of MG in rainbow trout muscle. Moreover, blank muscle samples spiked with 10 mg/kg of crystal violet, leucocrystal violet, sulfamethazine, sulfathiazole, sulfadiazine, and oxytetracycline were analyzed. The results showed that addition of the possible interfering compounds did not give interfering peaks near the retention time of MG. The correla-tion coefficient for the regressed curve (y ¼ 1.25292x À 0.224949) of MG standard over the range of 0e100 ng/ml was 0.9995, indi-cating good linearity of HPLC-DAD response.