Evalution Of Novel Solid Phase Extraction Material And Its Application In Detection Of Pesticide Residues

The study for adsorption properties and mechanism of the novel solid phaseextraction(SPE) material has carried on. The application in pesticide residues detectionof Cleaning-P2SPE column which using the novel SPE material as sorbent isdeveloped. The application scope of the SPE column is ascertained, and establish thepesticide residues platform of fruits and vegetables matrices. The developed SPEcolumn performances good, and it's cheaper than similar products, which make itvaluable in application.A gas chromatography-mass spectrometry (GC-MS) method for multiplepesticides was developed.45kinds of organophosphorus, organochlorine, triazine andpyrethroids pesticides which are suitable for GC-MS detection were chosed in thisthesis. Based on the optimization results of initial column temperature, flow rate andtemperature program, the best conditions of GC-MS was determined as the detectionmethod for the follow-up study.The study for adsorption properties and mechanism of the novel solid phaseextraction(SPE) material has carried on. Adsorption kinetics, adsorption isotherm andadsorption thermodynamics of novel SPE material were studied with quinalphos as anexample. The results show that adsorption kinetics could described by second orderadsorption dynamic model, and the intra-particle diffusion model fitting well, whichshow the adsorption process is complicated and not determined by a single factor;Adsorption isotherm fits Freundlich equation which indicate for the multilayeradsorption, adsorption isotherm results obtained by different temperatures indicate thatadsorption decreased with the increasing temperature; Adsorption reaction can beconsidered as spontaneous exothermic reaction for the adsorption thermodynamicsparameters (?G?0??H?0), and the conclusion that adsorption process containsboth physical adsorption and chemical adsorption can be speculated by the value of?H which is-70.72kJ/mol. The actual maximum adsorption of two specifications ofCleaning-P2column (60mg/3mL,200mg/6mL) were studied, and two specificationsSPE are overload when add over90?g and190?g quinalphos respectively. Theadsorption properties performs well which can meet the need of multiple residuedetection of pesticide.The application development of Cleaning-P2cartridge in detection of pesticidesresidue.By optimizing the extraction solution and dosage, extraction times, sample,leaching and elution solvent, the pretreatment method was determined for three-times ultrasonic extraction with10mL acetonitrile,5%acetonitrile-water (acetonitrile/water=5/95, v/v) as sample and leaching solution, and elute with dichloromethane, and GC-MS was used as detection method after pretreatment. The limit of dtection(LOD) andlimit of quantitation (LOQ) of SPE-GC-MS method used in watermelon is0.6?g/kg-6.0?g/kg and2.0?g/kg-20.0?g/kg respectively. The add mark recovery rate results of45pesticides was achieved with this method was used, the results of recovery rate aregood in organophosphorus, organochlorine, triazine, and bad in pyrethroids pesticides.The relative standard deviations (RSDs) are not more than17.18%.Establishment of the pesticide residue testing platform in fruits and vegetables.12representative vegetables and fruits matrices were chosed for apply this SPE-GC-MSmethod, and the good recovery results and purification effect show Cleaning-P2couldmeet the need for multi pesticide residues in different matrices.