Simultaneous Analysis of Selected Typical Antibiotics in Manure by Microwave-Assisted Extraction and LC-MS n

Analysis of antibiotics in the environment has become an urgent issue. A novel method entailing microwave-assisted extraction (MAE) and high-performance liquid chromatography-electrospray mass spectrometry (LC-MS (n) ) has been developed for determination of selected typical antibiotics, including quinolones, sulfonamides, and tetracyclines, in manure. Compared with ultrasonic extraction, MAE significantly increased recovery of fluoroquinolones (63-106%), sulfonamides (64-133%), and tetracyclines (64-109%) from manure. Acetonitrile acidified with formic acid buffer solution (pH 4.0) was used for extraction of swine manure whereas chicken manure was extracted with 0.1 M EDTA-McIlvaine buffer solution. Limits of quantification (LOQ) for all compounds were in the range 5.12-168.4 mu g kg(-1) dry matter, which were satisfactory for analysis of all samples. The suitability of the method was assessed by analysis of manure from six different sites.