Preparation Of Polyether Polyurethane Solid Phase Microextraction Membrane And Its Application In The Detection Of Pyrethroid Pesticide Residues

In order to improve the stability,volatility and the detection sensitivity of samples,it is necessary to pretreat the samples for separating the matrix and interfering substances coexist.Solid phase microextraction(SPME)originated in the early 90 s is used to separate and enrich the sample before the treatment of the sample,which is based on the equilibrium distribution between the matrix and the stationary phase.It has been widely used in many areas due to easy operation,fast analysis speed,high separation efficiency,small sample consumption and high sensitivity.SPME membrane is a kind of solid phase micro extraction membrane which is coated with solid phase micro extraction coating material on the membrane substrate.It inherits the extraction mechanism of solid phase microextraction and retains the advantages of solid phase microextraction.Moreover,it has a simpler process and lower cost than solid phase mioroextr-action.In this paper,organic silicon modified polyether type of polyurethane copolymer were synthesize using toluene 2,4-TDI,PEG-600,hydroxy silicone oil as raw materials,stannous octoate as catalyst and cyclohexanone as solvent.The solid phase micro extraction membrane was coated on the aluminum foil paper with a film coating device.The structure of prepolymers and production were investigated by infrared spectroscopy via analyzing the reaction conditions including reaction temperature,time,and the rate of monomer material.The morphology on surface of member and the element distribution such as Si and O were analyzed by scanning electron microscopy.The polyurethane film coated on the aluminum foil had stable performance,not easy to fall off,the decomposition temperature was 260 with smooth film surface and the element distribution.Further,the self-made solid phase microextraction membrane device was coupled with GC for extraction membrane application test.Extraction temperature,extraction time,salt content and film thickness on the adsorption efficiency were discussed and the elution solvent was chose.The extraction effect was compared with that of commercial PDMS solid phase microextraction membrane,and the volume fraction of the self-made film was higher than that of the PDMS coating,and the adsorption capacity of the 5 pesticides was better than that of the.The measured peak area and concentration of the material showed a good linear relationship,the correlation coefficient of 5 pyrethroid pesticides(R2)were 0.9985,0.9994,0.9989,0.9993 and 0.9991;the lowest detection limits were 0.003~0.011?g·mL-1;recovery rate in the 78.7%~99.5% standard.The results showed that self-made SPME has good thermal stability with low cost and good adsorption properties for pyrethroids which have superior prospect in development and application.