| With the rapid economic development, food safety attracts more and more attention after the problem for the food supply was solved. Pesticide, veterinary drug and additive residues in food have attracted more and more attention in many countries, regions and organizations which have issured the maximum residue levels (MRL) in food. The development of detection technology of residues in food has been focused on two major aspects: to develop rapid detection technology and to establish new methods of sample pre-treatment. At present the trend of the development for detection technology is toward simple, on-site, fast, low cost, automated direction, and for samples pre-treatment technology is toward the time-saving, labor-saving, low to reduce the organic solvents, reducing environmental pollution sample preparation.In the thesis the microwave-assisted extraction and matrix solid-phase dispersion extraction was used as the pretreatment technology to extract pesticide, veterinary drug and additive residues in food samples. The main performances of microwave-assisted extraction are fast, solvent-saving, and good at to extract hot-instable components that can decomposed of analytes under long time and high temperature heating. Matrix solid-phase dispersion extraction technology has a unique feature by which the solid, semi-solid and viscous sample, and even liquid sample can be directly trended and emulsification in the process of liquid-liquid distribution can be avoided. This method is time-saving and low solvent consuming. Matrix solid-phase dispersion extraction technology has been widely used in sample analysis.In this thesis animal foods were used as the samples. The microwave- assisted extraction and matrix solid- phase dispersion extraction as the sample pre- treatment technologies were used to extract several pesticides (e.p. triazines herbicides and pyrethroid insecticides), veterinary drugs (e.p. quinolone antibiotics and non-steroidal anti- inflammatory drugs) and non-food additives (e.p. Sudan red colorants) residues from animal food.The first part of the experiment is to use microwave- assisted extraction as sample pre-treatment method to extract four triazine herbicides from sheep liver sample. Some microwave- assisted extraction conditions, such as extraction temperature, extraction time, extraction solvent and volume of solvent, were optimized. RP-HPLC-UV was applied to the separation and detection of four triazine herbicides. The results indicate that when 10mL of methanol was used as extraction solvent, microwave irradiation temperature was 70℃and extraction was 6min, four triazine herbicides can be effectively extracted from sheep liver. And using methanol- water (70: 30, v/v) as the mobile phase, setting 220nm as the detection wavelength and maintaining the column temperature at 25℃, it can achieve to separate and detect these four triazine herbicides in 18 min. The further experiments prove that the proposed method has good precision (RSD 2.7-10.2%), accuracy (the recovery of four analytes is 90% to 102%) to detect four triazine herbicides from sheep liver sample.The second part of the experiment is that the microwave- assisted extraction coupled with high performance liquid chromatography was applied to the determination of quinolones (fleroxacin, lomefloxacin and sparfloxacin) and non-steroidal anti-inflammatory drugs (ketoprofen and ibuprofen) in animal tissues (sheep liver and bovine muscle) and bovine milk. In order to optimize the operational conditions, the L16 (45) orthogonal experiments were used to optimize the extraction temperature, extraction time, extraction solvent and solvent volume. The experimental results show that when 10mL of acetonitrile is used as extraction solvent, under 40℃to make 1g of tissue and milk samples be irradiate for 6min the five veterinary drugs can been effectively extracted. Using acetonitrile- 0.05 mol L-1 phosphoric acid buffer of pH 2.4 adjusted by triethylamine as the mobile phase, setting the flow rate at 0.8 mL min-1, selecting four wavelength (298, 289, 255 and 220nm), maintaining the column temperature at 25℃and these five analytes can be separate in 25min. Compared with the classical ultrasonic extraction, the proposed method is simpler, less extraction organic solvent (10mL) and extraction time (6min) were required. The good precision (RSD of inner-day and inter-day is 0.8-8.2%) and accuracy (the recovery of five analytes is 60% to 109%) were obtained.The third part of the experiment is the application of matrix solid- phase extraction coupled with high performance liquid chromatography to detect two pyrethroid drugs in porcine tissues. The experimental conditions, such as dispersion phase, purification phase, eluting solvent and solvent volume were optimized, respectively. The result indicates that when neutral alumina is used as dispersion phase, diatomaceous earth as purification phase and n-hexane as eluting solvent, these two pyrethroid drugs can be separate from the porcine tissue samples. The high performance liquid chromatography was applied. A reverse phase C18 column was used.Acetonitrile-water (85: 15, v/ v) was used as mobile phase. The detection wavelength was 210nm. In 13min two pyerthroid drugs can be separated and detected. The proposed method is rapid, simple and can extract and purify the analytes in one step. The HPLC-UV detection provides excellent precision (RSD 1.5-5.8%), accuracy (the recovery of analytes is 85% to 105%).and LOD (not more than 0.02μg g-1) for the quantitative analysis of those analytes in different porcine tissue samples that can content the requests of some directives (e.p. European Union Council Directive n. 93/57/EEC).The last part of the experiment is using matrix solid-phase extraction to extract four sudan red residues in sausage sample. The operational conditions were studied and optimized in details. The result indicates that when neutral alumina (de- activated by 4% moisture, w/ w) is used as dispersion phase and another part of neutral alumina as purification phase and n-hexane solution with 10% acetone is used as eluting solvent, four sudan red residues can be separated and purified in one step. Then using acetonitrile- methanol (20: 80, v/v) as mobile phase, maintaining the column temperature at 30℃, setting 505nm as detection wavelength, four sudan red residues can be separated and detected effectively. Compared with the national standard method, the purification efficiency is much better, less time, solvent and sample were required. This method has good precision (RSD of inner-day and inter-day is 0.7-3.6%), accuracy (the recovery of analytes is 76% to 111%) and LOD (not more than 0.02μg g-1).
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