Column Clean-Up Coupled With Extraction Technology For Determination Of Polycyclic Aromatic Hydrocarbons In Environmental Water Samples

With the acceleration of the industrialization process,the problem of environmental pollution has been increasingly prominent,posing a serious threat to the life safety of human and animals.In recent years,the living conditions of people have been considerably improved,and the requirements for environmental quality have also effectively imposed.There are many carcinogens in the environment,and polycyclic aromatic hydrocarbons(PAHs)are one of the most widely distributed representative persistent organic pollutants(POPs).Since the amount of PAHs in the environment sample is in trace levels,and many kinds of interferents maybe affect the accuracy of the determination of PAHs.It is extremely important to establish a simple,effective and environmentally friendly sample preparation method.Before the extraction of analytes in the sample,the column clean-up technology can be used to remove most of the interferents in the samples,thereby achieving the purpose of reducing the matrix effect.There are many sample preparation methods reported previously,which are widely applied to the food,biomedicine,environment and clinical analysis.The combination of column clean-up technology and some extraction methods can not only reduce the interference of the sample matrix,but also improve the sample processing speed,shorten the processing time and improve the working efficiency.In this thesis,self-assembled sample purification extraction device was used.PAHs were uesd as the target analytes.Straight-chain alkanes and triazine herbicideswere used as the main interferents.Gas chromatography and gas chromatography-mass spectrometry were used as detection methods.Two new types of sample pretreatment methods were applied to the detection of PAHs in environmental water samples.The separation and enrichment of PAHs in environmental water samples was carried out using column clean-up coupled with continuous flow-single drop microextraction.Various experimental parameters affecting extraction efficiency were studied and optimized,including the type of column packing,the ratio of material to liquid,the type and volume of extraction solvent,the flow rate of sample,ionic strength and pH.Under the optimal experimental conditions,H103 macroporous adsorption resin was selected as the purification material,and the ratio of material to sample solution was 12:5.5 ?L of cyclohexane microdroplet was used as the extraction solvent.10% NaCl was added to the sample solution.The flow rate of the sample solution passing through the clean-up column was 0.50 mL/min.After the extraction was completed,the droplet was withdrawn back into the microinjector and injected into gas chromatograph-mass spectrometer.The method has a good linearity in the range of 0.02-10.0 ?g/L.The limits of detection and quantification are0.0012-0.0101 ?g/L and 0.0041-0.0336 ?g/L,respectively.The proposed method was applied to the analysis of environmental water samples.The recoveries were81.8-105.8%,and the relative standard deviation was less than 7.0%.PAHs in oil-field water samples were extracted by column clean-up coupled with dispersive liquid-liquid microextraction.Firstly,the sample solution was purified with H103 macroporous adsorption resin.Secondly,the analytes were extracted and concentrated by the traditional dispersion liquid liquid microextraction method,and finally the extraction phase was injected into gas chromatograph for analysis.In this experiment,the effects of the type and amount of column packing material,the column flow rate,the type and volume of extraction solvent and disperser solvent as well as extraction time on extraction efficiency were studied.Under the optimal experimental conditions,H103 macroporous adsorption resin was selected as the purification material,and the ratio of material to sample solution was 12:5.The flowrate of the sample solution passing through the clean-up column was 4 BV/h.15 ?L of carbon tetrachloride was used as extraction solvent.1.00 mL of acetone was used as disperser solvent.After extracting for 2 min,the organic phase was injected into gas chromatography.The linear range for determining the analytes is 0.01-50.0 ?g/L,and the limits of detection are 1.1-5.3 ng/L.The method was applied to the analysis of the oil-field water samples,the recoveries was 82.6-104.6%,and the relative standard deviation was less than 6.8%.