Novel Microextraction Technique In Application Of Pesticide Residue

Carbamate and organophosphate pesticides were widely used to improve agricultural production. It's of great significance for improving the quantity and quality of agricultural products. Although these highly toxic pesticides can increase agricultural production and reduce the cost of lawn maintenance, etc., but the bioaccumulation of the food chain may affect human health. Traditional analysis methods of carbamate and organophosphorus pesticide residue such as liquid-liquid extraction, solid-phase extraction use large amounts of solvent, time-consuming, and it would cause secondary pollution to the environment. Therefore, an efficient, rapid method is required for the determination of carbamates and organic of pesticide residues.In such cases, single drop liquid-liquid microextraction, liquid phase dispersive microextraction, molecularly imprinted solid-phase extraction is generated by a sample pretreatment technology. Single drop liquid-liquid phase microextraction mainly due to distribution of analytes between single drop of the syringe tip and the water samples; the liquid phase dispersive microextraction achieves a very large specific surface area and the mass transfer process can be completed in the shortest time; molecularly imprinted solid-phase extraction identifies with specific capabilities, and compared to traditional solid-phase extraction, can be reused. In this thesis, these three methods were used to determine the carbamate and organophosphate pesticide residues, respectively. The main research contents are as follows:1. Single drop liquid-phase microextraction method was evaluated by analyzing carbamate and organophosphate pesticide residues at the same time. Gas chromatography mass spectrometry was used to analysis the water samples and investigated the impact of extraction of a variety of factors, such as the type and content of extractant, extraction time, pH, ionic strength, and to determine the best extraction conditions. The actual water samples was used analyzed in the conditions.2. A new type of liquid phase dispersive microextraction was used coupled with gas chromatography tandem mass spectrometry to analysis water samples and carbamate pesticide residues. The impact of the dispersive of microextraction extraction conditions was investigated, such as the extractant type and content, the dispersive agents of the type and concentration, extraction time, pH, ionic strength. The best conditions was determined, and applied to the determination of the actual water samples.3. Proposed a microwave-assisted synthesis of molecularly imprinted solid-phase extraction method, and carbofuran in water samples was used in the analysis under used of UV spectrophotometer analysis. The microwave-assisted synthesis conditions was optimized for suspension polymerization of carbofuran. Carbofuran and its analogues have done a solid-phase extraction assay, and the molecularly imprinted solid-phase materials used in practical analysis of water samples.