[Concentrations of antibiotics in vegetables from manure-mended farm]

Sixteen typical antibiotics including four tetracyclines, four quinolones, and eight sulfonamides in vegetables from manure-amended farm were determined using the ultra high performance liquid chromatography-tandem mass spectrometry and their health risks to human via the diet pathway was assessed. Most antibiotics were frequently detected in vegetable samples, with the detection rate from 11% to 90%. Concentrations of a single compound were mainly less than 5 microg x kg(-1) (D. W.), with the maximum of 23.88 microg x kg(-1) and the average of 0.91 microg x kg(-1), respectively. Norfloxacin, ciprofloxacin, sulfamehtaoid and sulfadiazine were the dominant compounds. At least one antibiotic was detected in a single vegetable samples, and even up to ten antibiotics. The concentration of quinolones in underground parts was higher than those in aboveground parts. Intake dose of antibiotics via the consumption of the detected vegetables was lower than ADI, suggesting a lower health risk. But combination toxicity and resistance of antibiotics should not be ignored.