Abstract

Florfenicol is a synthetic broad-spectrum antibacterial compound used in aquaculture for prevention and treatment of fish diseases. The main mode of administration used in aquaculture is through the fish feed, which makes it very important to control the concentration of the drug in the feed, to ensure application of an appropriate dose to the fish. The objective of this work was to develop a high-throughput planar chromatographic method for monitoring the dose of florfenicol in fish feed. Florfenicol was extracted with methanol and chromatography was performed on silica gel F 254 HPTLC plates with ethyl acetate-n-hexane, 80 + 20 (v/v) as mobile phase. Quantitative analysis was performed by densitometry in absorbance mode at λ = 223 nm. The calibration plot wa s linear in the range between 20 and 80 ng per spot with a coefficient of determination (r 2) of 0.9987. The limits of detection and quantification were 2.55 and 8.50 mg kg -1, respectively. Recovery at 50, 500, and 1500 mg kg -1 was 101.71 ± 2.34, 85.18 ± 2.32, and 81.91 ± 2.92 respectively. The proposed method is sensitive, accurate, precise and suitable for monitoring florfenicol dose in medicated salmon fish feed.