Submitted to: Journal of Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2009
Publication Date: 8/8/2009
Citation: Chen, G. 2009. Analysis of oxytetracycline residue in salmon muscle using a portable analyzer based on Eu III luminescence. Journal of Food Additives & Contaminants. (26):1172-1179. Interpretive Summary: Total global farmed salmon production surpassed wild catch in 1998 for the first time in history, and reached 1.3 million tonnes in 2005. However, infectious diseases pose a profound impact on salmon population. Oxytetracycline (OTC)was approved by the U.S. Food and Drug Administration (FDA) to use in salmon. Worldwide, it is the most prominent antibiotic in aquaculture to treat a wide range of bacterial infections. This practice may leave OTC residue in salmon contributing to allergic reactions and emergence of antibiotic-resistant pathogens. To protect public health, the tolerance of total tetracycline in edible animal muscle was set by the FDA and regulatory agencies all over the world. In this work, OTC residue in salmon muscle is determined by europium-sensitized luminescence (ESL) using a LED-based portable analyzer developed in this laboratory. The signal depends linearly on OTC concentration over a wide range (10-20000 parts per billion). With chromatography eliminated and sample preparation simplified, this method achieves excellent specificity and sensitivity for both residue and depletion analysis. Its improved throughput and field deployability can contribute to better consumer protection and other applications.
Technical Abstract: Oxytetracycline (OTC), one of tetracycline (TC) antibiotics, is the most prominent therapeutant in aquaculture worldwide. In this work, OTC residue in salmon muscle is determined by europium-sensitized luminescence (ESL) using an LED-based portable analyzer. OTC is extracted in EDTA-McIlvaine buffer, and protein precipitated in NaCl–trichloroacetic acid. Hydrophilic-lipophilic balance cartridges are used for cleanup. The ESL intensity, integrated over a 25-1000 µs interval, reveals a wide linear dynamic range (R2=0.9992 in 10-20000 ng g-1). With chromatography eliminated and sample preparation simplified, this method achieves high sensitivity (1.5 ng g-1 limit of detection at 3.60% average relative standard deviation), high specificity (6.1 ng g-1 background noise), and reasonable recovery (79.7% at 100 ng g-1). Its in-situ monitoring ability and improved throughput will contribute to food safety and other field applications.