The Extraction Method Research Of Traces Organic Pollutants In Soil

The pollution of organic pollutants is attracted more and more attention of experts.Soilenvironment is one of the most important Polluted areas. To take the use of pesticidesinagriculture for an example，existing data shows that: Application Rate of pesticide whichacts upon the crops，accounts for only10%-30%. In addition20%-30%absorbed fromatmosphere and water.50%-60%resided in the soil. Because Plants and some species getthe nourishment they need from soil，organic pollutants in soils transfer and transplant byfood chain，pollutes and make threats to animals and humans.In this program，the special emphasis has put on the extraction of the soil samples.Study of traces semivolatile organic pollutants in soil using ASE that develops fast of lateyears，chromatography and mass spectrometry.make a new method for semivolatileorganic pollutants in soils monitoring opens up.The present paper has three main parts:To begin with, test with smash way and degree of soil samples to work out theappropriate way. Choose the kinds of soild dispersant，analyze the effect of dispersantquantity on recovery. In accordance with the different characteristics of targets，choose aor some chemical agents as reagent to test and choose the appropriate one. Testextracting temperature from50°C to200°C，based on recovery，find the most appropriateone. Test extractive pressure and compare recovery under different pressures，find the bestone. Try to find out static extracting time，wash volume and numbers of cycling，choosethe appropriate condition. Evaluate the possibility using on-line purify， contrastpurification materials and column，choose the most appropriate condition. Carried out theexperimental analyses on spiked recovery of soil samples. Extract some real soil samples.Secondly, determine the testing methods of chromatography and mass spectrometry.Test concentration mode of extracted liquid，make the samples applicable to analyze. Inaccordance with extracted liquid，test targets and determine the testing methods ofchromatography(procedure heats mode，flowrate of carrier gas，volume of sample，injectortemperature etc)，choose the appropriate column，define retention time. In accordance withpurifing degree， choose the appropriate testing way. Optimize mass spectrometryparameter separate speculation against contents above，such as interface temperature，ionsource temperature，scan time，fragment ion，determine the mass spectrometry conditionthat is fit to different organic pollutant.Finally,verificafion of whole process parameter. Test organic pollutant targets about the following parameter: whole processaccuracy(recovery), The detection, linear range.