Quantitative detection of tetracycline residues in honey by a simple sensitive immunoassay

Tetracyclines (TCs) are widely used for prevention and control of infectious diseases and have a great activity against variety of Gram-positive and Gram-negative bacteria. Due to the widespread use of TCs in animal husbandry, it can lead to an increase the risk of TCs remaining in human food. To protect consumers, many countries have set acceptable tolerance levels for these drugs. Therefore, it is necessary to establish a suitable analytical technique with specificity, sensitivity and simplicity. The biotin-avidin mediated ELISA method was performed to determine TC residues in honey quantitatively. By using PBS-EDTA assay buffer at pH 7.2, a honey solution of TC standard was prepared and diluted. And no additional pre-treatment of sample was required in this method. The limit of detection and limit of quantitation of the optimized method were 3.98 x 10(-10) M (0.19 mu g L-1) and 7.94 x 10(-10) M (0.38 mu g L-1), respectively, and the dynamic range was from 1.52 mu g L-1 to 152 mu g L-1 of TC in honey No cross-reactivity was observed with the structurally similar compounds, and mean percent recoveries of TC spiked in honey ranged from 95% to 101%. Compared to other methods, this method was superior in terms of detection limit, dynamic range, and % recovery with simple sample-preparation. (c) 2008 Elsevier B.V. All rights reserved.