|
As the growing of human production, living, and the exogenous chemicals in the environment, food safety incidents occurred in our daily life, people began to improve public health awareness, drug residues in food has become a global challenge and a major global public health problem. For the broad-spectrum quinolone antibacterial, bactericidal ability, convenient for uesed, and less adverse reactions characteristics of veterinary clinical medicine, fluoroquinolones (FQs) have been widely used. But some erroneous understanding of these antibiotics has led to abuse of such antibiotics, and residues in food of animal origin. Therefore, developing of a selective, sensitive and rapid method for the determination of FQs in animal products is very important.The main purpose of this paper was to establishment a series of studies to use the different microwave-assisted methods to extract t he FQs antibiotic residues in chicken tissue, animal feed and honey.1. A new method was developed, in which the extraction and clean-up was performed in one step under the action of microwave irradiation. The method was used for determination of six FQs including enrofloxacin, ciprofloxacin, lomfloxacin, levlfloxacin, fleroxacin and sparfloxacin in chicken tissue. Compared to the traditional techniques which using shaking or stirring for the extraction, this method got the better recoveries. The limits of detection (LODs) of this method are from 2.7 to 6.7 ng/g, which are much lower than MRLs (100-500 ng/g) established by the European Union for FQS in chicken tissues, and effective simplified the experimental procedure and saved the time.2. The work provided an efficient and green method for simultaneous determination of five FQs in feed samples, which used Na2EDTA-Mcllvaine buffer as the extraction solvent and without organic solvent was used. The proposed method has low toxicity to human and is more environmental friendly. The extraction process was accelerated strongly by microwave heating. By comparison, the LODs of this method are from 5.0 to 9.1 ng/g, and the extraction efficient was much higher the use the ultrasonic extraction.3. A novel technique based on the improved dynamic microwave-assisted extraction (DMAE), which is used for elution FQs including enrofloxacin, ciprofloxacin, levlfloxacin, fleroxacin and sparfloxacin adsorbed in silica. The FQs were first extracted with potassium phosphate buffer (PB,0.05 M, pH 3.0), and then directly introduced into the solid phase extraction column which was packed with silica for preconcentration of analytes and clean-up of sample matrix. Subsequently, the FQs trapped on the silica were eluted under the action of microwave energy, and determined by liquid chromatography-tandem mass spectrometry. Compared to use the hydrophilic-lipophilic balanced for clean-up, the silica was much more cheap and easy to get, a satisfactory recoveries was obtained, the LODs were from 1.5 to 4.4 ng/g.
|