Studies On The Multi-residue Methods For Analysis Of Pesticide Residues In Apples

After accessing to WTO, the farm products producing in China arefrequently frustrated by technical barriers in export trade, among them, pesticideresidues are the main problems as the green barrier. Rrecently, Corea, EEC, andJapan are all raised the quality standard import farm produce. China has abundantapples, the problem of pesticide residues in apple has seriously frustrated theexport. Therefore, exploring and applying a fast, efficient and sensitive determinemethod is important and needed urgently to breakthrough the technical barriers,smooth flow apples to the world market.In this thesis, 41 pesticides which most commonly used in fruit garden and orfrequent appearance in apples were selected as the target substance. The brand-newmethod of matrix solid-phase dispersion (MSPD) technique was applied in sampleextraction, and 41 pesticides were determined by Gas Chromatograph (GC) andHigh-performance Liquid Chromatograph (HPLC). The results of the studies arelisted as followed:1. The Chromatographic instrumentation working condition for 16organophsphorus pesticides has been established. 16 organophsphorus pesticideswere well separated in 25 minutes (min) with good linearity ranges from 0.9943 to1.0000.2. An efficient method with florisil MSPD and GC-FPD technique fordetermination of 16 organophsphorus pesticide residues has been established. Therecoveries were 79.67%～104.68%, the coefficient variations(C.V.)≤4.15%, and thedetection limits were 0.0032～0.010mg/kg. This method can meet the demands fordetection organophsphorus pesticide residues in apples.3. The method for determination of 16 organophsphorus pesticide residues byneuter alumina MSPD and GC-FPD technique has been established. The recoverieswere 76.12%～105.13%, with the C.V.≤4.10, and the detection limits of 16pesticides were all less than the maximum residual limits (MRLs).4. The Chromatographic instrumentation working condition for 19organochlorine and pyrethroid pesticide has been established. 19 organochlorine pesticide residues were well separated in 30min with good linearity ranges from0.9947 to 0.9999.5. The method for simultaneous determination of 19 organochlorine andpyrethroid pesticides in apples with florisil MSPD and GC-ECD technique has beenestablished. The recoveries were 78.62%～103.42% with the C.V.≤4.06%, and thedetection limits were 0.000098～0.007mg/kg, which were all less than the MRLs.6. The method with neuter alumina MSPD and GC-ECD technique forsimultaneous determination of 19 Organochlorine and pyrethroid pesticides residueshas been established. The recoveries were 80.60%～104.20% with the C.V.≤4.37%.This method has high veracity precision, efficient and sensitive.7. The method for simultaneous determination of 6 carbamate pesticide residueswith florisil MSPD and Post-Column Derivatization techniques by high performanceliquid chromatography fluorescence detection has been established. The recoverieswere 81.50%～96.58% with C.V.≤3.54%, and the limits of determination were0.0032～0.010mg/kg. Post-Column Derivatization technique both greatly enhancedthe sensitivity of carbamate pesticides, and made the chromatogram peaks wellseparated.