Study On Solid Phase Extraction-Liquid Chromatography-Mass Spctrometric Methods For The Determination Of Pesticide Residues

High performance liquid chromatography and mass spectrometry(HPLC-MS) has grown to become a mature and routinely used technique in analytical chemistry since 1980'. HPLC-MS is an online coupling system of HPLC, a separation technique that can be applied to the extremely complex mixtures, and MS, the most sensitive method of molecular analysis that has the potential to yield information of the molecular weight as well as the structure of the analyte. It provides a low limit of detection and as an identifier for structural information. HPLC-MS has become a powerful and important technique and method in analysis of pesticide residues in the complex mixtures.In this thesis, the development and applications of HPLC-MS were reviewed. The basic principle and characteristic of HPLC-MS were introduced. The following aspects were investigated:I. The sample preparation methodA variety of factors, which effected on the recovery of the pesticides, have been investigated such as the different sorbents of solid phase extraction (SPE) cartridge, elution solvents, elution solvent volumes and the flow rate of sample mixtures and elution solvent. The results give a practical guide for the following sample preparations.II. Four high performance liquid chromatography mass spectrometry methods developed based on the solid phase extraction sample preparation technique1. A SPE-HPLC-MS method was developed to analyze flumetsulam, simazine, thiodicard, chlortolum, prometryn, fenobucarb, malathion and diazinon in vegetables. The method is simple, sensitive and repetitive. It is suitable for fast determination of pesticide residues in vegetables and other food.2. A SPE-HPLC-MS method for the determination of methamidophos, monocrotophos,...