Research On Analysis Method Of Seperating Six Indicative Polychlorinated Biphenyls (PCBs) Monomers In Enriched Environment Based On Magnetic Nanoparticle Assembly Materials

PCBs is an industrial synthetic outcome. With characteristic of environmental persistance,biological accumulation, high poisonousness, ability of long-distance migration, ect, it also ranksone of the ten environmental persistant organic pollutants（POPs）. Although PCBs has beenforbidden in production and application wordwide, it still remains in environment through variouschannels. Nevertheless, because of the characteristic of water indissolubility, PCBs in water hasalways been neglected and difficult to be discovered. It’s urgent to find an easy, fast and accuratemethod to quantitatively study the residue concentration of PCBs.At present, Nano materials study becomes a hot spot for material science and analysischemical study. Corresponding with the development of Nano material study, solid-phaseextraction is being applied to more and more analysis field, especially the magnetic Nano material,which is gaining favor of more and more analyst in analysis science. This paper will use carbonnano tube as stationary phase to build a set of solid phase extraction pretreatment method, andfurtherly use magnetic nano material（magnetic carbon nano tube and magnetic graphene oxiderespectively） to build pretreatment method of magnetic dispersive solid-phase extraction. Thussix indicative PCBS monomers in enriched water can be seperated combining with GC-MS. Mainresearch contens include:Chapter one A relatively detailed summerization will include pretreatment method anddetection method to PCBs in samples, nano material’s application to persistant organic pollutant assolid phase extraction absorbent.Chapter two Carbon nano tube will be used as solid phase extraction absorbent to enrichsix indicative PCBS monomers, and then optimize factors that can effect extraction recovery,including volume of samples, types of eluent, flow rate of elution, volue of elution, etc. At thesame time, recovery of some kinds of different stationary phase carbon nano tube, C18bondedsilica gel and active carbon. Using this method, detection linearity range for these poisonous sixPCBs monomers is10-200ng·mL^-1; relative standard deviation is2.3-5.1%; limit of detection is 3.1-6.9ng·mL^-1. Finally the method will be applied to analyze environmental water sample.Experimental result shows: adding standard recovery of multiwalled carbon nano tube to six targetcompound is79.5-96.9%. And the method only can be applied to pretreatment of PCBs compoundin natural water sample. It also proves the good absorption result about carbon nano tube to PCBs.Chapter three Based on favourable absorption characteristic of carobon nano tube to PCBs,a magnetic carbon nano tube composite material has been compounded to extract six PCBs inwater sample. Compound steps are: firstly compounding the nagatively charged Fe₃O₄nanoparticle with carboxylation; secondly combining it with hydrophilic positive-chargedpolyelectrolyte PDDA surfactant; adding carboxylation of carbon nano tube after dispose andimprovement, which finally result in Fe₃O₄@PDDA/MWCNTs magnetic composite nano material.This method is easy to operate. And it takes half time less comparing to normal solid phaseextraction. Through optimization of extraction conditions, recovery of experimental result is73.0-98.9%and relative standard deviation （RSD） is3.8%-9.4%. Meanwhile, a matching test has beenexperimented to absorption model and kinetics. It shows that it is an easy, novel and time-savinganalysis method with high recovery, which is built by composite material with magnetic seperation,enrichment and GC-MS.Chapter four Based on another water-solube graphene oxide（GO）, through coprecipitationmethod, Fe₃O₄@GO can be compounded only by one step. This method is eay with highproductivity. On the basis of chapter three’s experiment, this magnetic nano composite materialcan be applied to do absorption study to PCBs in water. Experiment shows that Fe₃O₄@GO is alsoan ideal absorbent to PCBs. After optimization of extraction conditions, adding recovery is74.6-101.4%and the relative standard deviation range is3.9-7.4%.