Determination Of Pesticide Residues In Water By Solid Phase Extraction-pressurized Capillary Electrochromatography

Pressurized capillary electrochromatography(p CEC) is a highly efficient micro-separation technology, which has developed rapidly in recent years. It set the advantages of high performance liquid chromatography(HPLC) and capillary electrophoresis(CE) as a whole, with "a machine with three separation means"(capillary electrochromatography, capillary electrophoresis, micro-diameter liquid chromatography), "three high and one fast"(high column efficiency, high resolution, high selectivity, fast separation), miniaturization, affordable. It has great advantages in the study of complex chemical and represents of the trends of efficient micro separation in academic analysis.This dissertation is divided into four chapters as follows:The first part briefly introduces the background and significance of this project, including categories of pesticide and water environmental comtamination, principles and applications of CEC and p CEC, overview of analytical method for pesticide residue.The work of the second part is mainly to use p CEC-UV to analyze weak-polar pesiticide residues in water by combining solid phase extraction and its application in the detection, the separations were performed on a reversed-phase C18 capillary column with the particle diameter of 1.8 μm, the mobile phase was consist of 66% v/v acetonitrile and 34% v/v of 5 mmol/L Tris-HCl(p H 7.1) at a pump flow rate of 0.06 m L/min with the separation voltage of-9 k V, eight pesticides were separated within 16 min in isocratic p CEC mode. The linear range of the eight pesticides ranged, respectively, from 3.4 to 100 μg/m L(dimethoate), from 8.1 to 120 μg/m L(dichiorvos), from 1.2 to 50 μg/m L(carbofuran), from 0.2 to 50 μg/m L(carbaryl), from 0.1 to 50 μg/m L(atrazine), from 3.7 to 100 μg/m L(methyl parathion), from 11.2 to 150 μg/m L(malathion), from 2.1 to 100 μg/m L(chlorothalonil). Correlation coefficients between 0.9961 and 0.9997, limit of detection between 0.03 and 3.7 μg/m L. Average recoveries between 71.0 and 114.1% and relative standard deviations between 1.1 and 9.8% were obtained.The work of the third part is mainly to use p CEC-UV to analyze non-polar pesiticide residues in water by combining solid phase extraction and its application in the detection, the separations were performed on a reversed-phase C18 capillary column with the particle diameter of 1.8 μm, the mobile phase was consist of 90% v/v acetonitrile and 10%v/v of 5 mmol/L phosphate buffer(p H 6) at a pump flow rate of 0.08 m L/min with the separation voltage of-6 k V, three pesticides were separated within 13 min in isocratic p CEC mode. The linear range of the eight pesticides ranged, respectively, from 4 to 100 μg/m L(parathion), from 6 to 100 μg/m L(chlorpyrifos), from 1.5 to 50 μg/m L(deltamethrin). Correlation coefficients between 0.9966 and 0.9989, limit of detection between 0.5 and 2.0 μg/m L. Average recoveries between 71.4 and 107.2% and relative standard deviations between 2.0 and 9.5% were obtained.The last part is to summarize shortage of this system and expectation of p CEC.