Ultrasonic Nebutization Headspace Hollow Fiber Microextraction Of Pesticides And Veterinary From Panax Ginseng And Honey

The ultrasonic nebulization headspace hollow fiber microextraction（UN-HS-HFME） was applied to the extraction of the analytes from samples. Thethesis contains two parts: UN-HS-HFME was applied to the extraction of pesticidesfrom root of Panax ginseng C.A.Mey.; UN-HS-HFME was applied to theextraction of veterinary medicines from honey.During the experiment, The extraction and enrichment process can be performedsimultaneously. Solid samples were first crushed by high-speed disintegrator and thenextracted. The liquid samples were extracted directly. After extraction, the enrichmentwas carried out with the hollow fiber in headspace. The effects of some parameters,such as the kind of acceptor solvent in the pore of the fiber wall, the shape ofextraction vessel, the sample amount, extraction time, salt concentration in extractionsolvent, pH value of the acceptor solution, the time of ultrasonical elution, and theelution times were examined. When the UN-HS-HFME was completed, the resultingsolution was directly injected into the HPLC system. By determining of calibrationcurves, intra-day and inter-day precision and the recoveries, the precision, accuracyand enrichment efficiency were examined.The pesticides in roots of Panax ginseng C.A.Mey. were extracted anddetermined. The experimental conditiong, including sample amount （500mg）, NaClconcentration（10%）, extraction time（20min）, acceptor solvent（1-octanol）, pH of theacceptor solution（pH=3）, elution time（5min）, elution times（2） were chosen. Thedetection limits for simeton，monolinuron, chlortoluron，karmex, and prebane werefound to be18.2²2.2μg·kg^-1, the recoveries for the analytes were between70.77and 132.80%and the RSDs for determining the analytes were2.1–16.1%. The precisionand accuracy for the proposed method should be satisfactory.The sulfonamides in honey samples were extracted and determined. Someparameters, including the type of extracting vessel, NaCl concentration （15%）,extraction time（20min）, acceptor solvent（1-octanol）, pH of the acceptorsolution（pH=2）, elution time（5min）, elution times（2） were chosed. The detectionlimits for SMD, SDX, SMT, SDM and SPP were found to be14.2,29.4,12.7,28.6and27.7μg·kg^-1 respectively. The recoveries for the analytes were between88.6¹16.2%and RSDs were3.0–11.2%.Besides volatile and semi-volatile compounds, the non-volatile compounds alsocan be extracted and determined by the proposed method. The extraction andenrichment process can be performed simultaneously. UN-HS-HFME has theadvantages such as less expenditure of time, high enrichment efficiency, highprecision, high accuracy and satisfactory detection limit.