A high-throughput screening method for determination of multi-antibiotics in animal feed.

Abstract

A high-throughput method based on ultrasonic-assisted extraction, 96-well plate thin-film microextraction was established to determinate 18 antibiotics in animal feed. In this method, the extraction was implemented by ultrasonic-assisted extraction for 30 min with disodium ethylenediaminetetraacetic acid-McIlvaine buffer (pH = 5) containing 6% sodium chloride (w/v), purified by thin-film microextraction and combined with 96-well plate system to improve the efficiency. Optimization of thin-film microextraction conditions was performed by methods of single factor and response surface, and finalized as: condition time: 20 min; adsorption time: 55 min; washing time: 5 s with water; desorption time: 30 min with acetonitrile/water (8:2, v/v) containing 0.1% formic acid (v/v). Evaluation of different extractive phases showed that polystyrene-divinylbenzene-polyacrylonitrile was the optimum coating. The analysis was performed by ultra-high performance liquid chromatography-tandem mass spectrometry. Recovery, inter- and intra-day precision, linearity, limit of detection and quantitation were evaluated. The average recoveries of 18 antibiotics were 66.6-93.5% at three spiked levels, intra-day precision was 1.0-8.4% and inter-day precision was 3.0-16.4%. The linearity was good for r2 > 0.99. Limits of detection and quantification were found in the range of 1-14 μg/kg and 4-48 μg/kg, respectively. This article is protected by copyright. All rights reserved.