Study On Analysis Methods Of The Pestisides And Their Degradation Products

Four parts are given in this thesis, the main results are expressed as follows:1. Investigations have been performed on the determinaton of acetamiprid. In a suportting electrolyte containing 0.2mol I/'NaOH+Omol LH3BO3+Q.2mol L"'KC1 at pH=10.0, acetamiprid produces a sensitive catalytic hydrogen wave by single-sweep polarography. The peak potential is -1.59V(vs.SCE). The linear relation between holds the peak current and the acetamiprid concentration in the range from 7.0xlO5molL~17.0xlO"4molL"1. A sensitive method for determination of acetamiprid by single-sweep oscillopolarography was developed. The method has been compared to acetamiprid's HPLC method. And the mechanism of elctrode reduction is discussed.2. Acetamiprid and imidacloprid are two novels pesticides among the chloronicotines, which have the closely structure. In this wok, the separation of acetamiprid and imidacloprid by MEKC is studied. In order to modify the separation, sodium dodecyl sulfate is added to buffer to form a micellar. Several factors affecting the separation are examined: background electrolyte, SDS concentration and pH value of buffer solution. The two pesticides can be satisfactorily separated within 10 minutes using a 75cmx50um uncoated flexible fused silica capillary colume (effctive length= 60cm) and using buffer solution consisting of a mixture of lOmmolL"1 borate buffer (pHS.O), 22mmolL~l SDS and 4% methanol in water.3. In this wok, two pesticides- acetamiprid and imidacloprid and three sulfonylurea herbicides-chlorsulfuraru metsulfuron methyl and chlorimuron ethyl are separated by MEKC with migration time < 13 minutes using a 75cmx50um uncoated flexible fused silica capillary colume (effctive length^ 60cm) and using buffer solution consisting of a mixture of lOmmolL"1 borate buffer (pH8.0),54mmolL"' SDS and 4% methanol in water. SDS concentration is examined for getting the best separation.4. The photochemical degradation of metsulfuron methyl has been investigated by ultrviolet spectrum and micellar electrokinetic chromatography (MEKC); the degradationpathway of the herbicides was elucidated and its degradation pruducts were separated by MEKC using a 75cmx50um uncoated flexible fused silica capillary colume (effctive length =60cm) and using buffer solution consisting of a mixture of lOmmolL"1 borate buffer (pHS.O), 54mmolL"' SDS and 4% methanol in water.