Research On The Determination Of Pesticide Residues In Water Samples By DSPE-UPLC-QTOF/MS

This thesis studied and established a new evolution in the traditional dispersivesolid-phase extraction technology based on solid phase extraction (DSPE), which cameafter experiments and comparisons show that the method can urethane water enrichedaccurate, efficient and the organic phosphorus pesticide, the experiments also usedcarbamate tandem flight the mass spectra of the time with the pretreatment method ofenriched and advanced organic phosphorus pesticide liquid chromatography analysesaccurate qualitative and quantitative.This paper reviews the historical development of pesticides in the first chapter, thepesticides and the characteristics of its harm to environment and human. The paperintroduced the research of pretreatment on pesticide in the sample, and the advantagesand disadvantages of various pretreatment were compared. Introduces the application ofsolid phase extraction in pesticide pretreatment, analyzes the advantages anddisadvantages of the traditional solid phase extraction, finally introduces a newpretreatment technology in solid phase extraction based on theory of dispersive solidphase extraction (DSPE).In the second chapter describes the combination of high performance liquidchromatography tandem time of flight mass spectrometry with dispersive solid phaseextraction pretreatment technique by using the (HPLC-QTOF/MS) determination ofcarbamate pesticides in water samples, the factors and dispersive solid phase extractioneffect on impact (including HC-C18the amount and mode of activation, shakingextraction time, eluent the type and volume, pH value of water and the volume of fluidmatter analysis, parameters and so on) combined with optimized. Under optimizedconditions (extraction agent0.5g in advance by an amount of methanol soaking treatedHC-C18samples was2, pH,20min,5mL the oscillation extraction acetone eluting),3kinds of carbamate pesticides have good linear relationship in the0.5-100.0g/L range,the lowest detection limits were respectively6.4,11.3,10.46ng/L, relative the standarddeviation (n=3) of less than10.4%, the recovery of standard addition level of0.5g/L rateof72%-110%, this method can satisfy the water were measured before treatment andanalysis of3kinds of carbamate pesticides.In the third chapter describes the combination of high performance liquid chromatography tandem time of flight mass spectrometry using pretreatment technologydispersive solid phase extraction (HPLC-QTOF/MS) for the determination of organicphosphorus pesticide classes in water. In the experiment of extraction agent usage andthe mode of activation, water pH, extraction time, elution factors influence the type anddosage of agent selection and optimization. When the extracting agent is0.4g HC-C18,pre soaking treatment, methanol water pH6, shaking extraction20min, eluent is5mL indichloromethane,3kinds of organic phosphorus pesticide has better recovery rate; and inthe range of good linearity determination of0.5-100.0mu g/L (R2=0.9955-0.9983), LODis greater than6.4ng/L, the relative standard deviation the actual sample determination(n=3) between5.6%-11.1%, the recovery rate was82.4%-108.1%. Has a goodreproducibility and accuracy, which can measure the pretreatment and analysis to meetthe water of3kinds of organic phosphorus pesticides.Through these two kinds of pesticides in the pretreatment method of the advancedenrichment in the water, as well as a comparison with using traditional solid phaseextraction effect, we find that this method has high efficiency of enrichment, the use oforganic solvent less, simple and reliable operation and rapid characteristics, especiallywhen dealing with the water more turbid than dirty with solid phase extractioncomparison has obvious advantages, can overcome the extraction column sieve plategenerally exist in the traditional solid-phase extraction of easy blockage, extraction timeis long, operation cumbersome disadvantage.