Preparation Of A Novel Solid Phase Microextraction Fiber Based On Cucurbit[7]uril Derivatives And Its Application In Determination Of Analytical Detection

Solid phase microextraction?SPME?is a novel sample pretreatment technology which combining with sampling,purification,concentration and injection.It has the advantages of solvent-free,rapid,efficient and convenient and has a wide range of applications in environment,food and biological field.In SPME,the coating is vital for solid phase microextraction,which determines the sensitivity of the analytical method,the selectivity of the extraction,the reproducibility of the determination and the durability of the fiber.So,the preparation of a wide range of high efficiency and durability coating materials are main trends of current research.In this paper,a new novel of PDMS/Q[7]-OCH₂CH=CH₂ solid phase microextraction fiber head was prepared by sol-gel technique.The extraction performance of the coating was investigated by gas chromatography?GC-FID?which combined solid phase microextraction fiber head to determine organochlorine and organophosphorus pesticide residues in vegetables.The main research contents are as follows:1.The research progress of solid phase microextraction and the main form of extraction technology are introduced.The types,preparation methods and practical environment,food and biology application of solid phase microextraction coatings are reviewed.2.The synthesis of monohydroxy Q[7]-OH was carried out by ammonium persulfate oxidation method and the separation and purification of Q[7]-OH was conducted by silica gel column chromatography.Q[7]-OH was reacted with Na H,Br CH₂CH=CH₂at room temperature in DMSO to compound allyloxy-Cucurbit[7]uril Derivatives?Q[7]-OCH₂CH= CH₂?,and the crude product was separated and purified by ether and methanol and its structure was characterized by IR and 1H-NMR.3.The ?-glycidoxypropyltrimethoxysilane?KH-560?was coupled with Q[7]-OCH₂CH=CH₂.A novel PDMS/Q[7]-OCH₂CH=CH₂ solid phase microextraction fiber coating head which properties were analyzed by infrared,thermogravimetric and scanning electron microscopy was prepared by sol-gel technique.Infrared analysis showed that Q[7]-OCH₂CH=CH₂ had a binding reaction with PDMS and became a part of the coating.Thermogravimetric analysis showed that the PDMS/Q[7]-OCH₂CH=CH₂ solid phase microextraction fiber coating had a good thermal stability that maximum operating temperature was about 320?.Scanning electron microscopy?SEM?showed that the surface texture of the coating was rough,uniform,dense,loose and free from cracks.Moreover,the reproducibility of the extractor was examined.The results showed good reproducibility and reusable use.4.Established a analysis method of PDMS/Q[7]-OCH₂CH=CH₂-Fiber-SPME-GC-FID for determination of phenols,polycyclic aromatic hydrocarbons,phthalates,anilines,organic chlorine,organic phosphorus 6 kinds of 39 different polar compounds for extraction analysis.The effects of extraction temperature,p H,salt concentration,extraction time and desorption time on the extraction efficiency were studied systematically.Compared with the self-made PDMS and the commercial coating,the extraction effect of the self-made coating on the different polar compounds is different,but the experimental results show that the PDMS/Q[7]-OCH₂CH=CH₂ coating has good selectivity for the extraction of different polar compounds,which has been proved that the functionalization of the cucurbit[7]uril and bonding to the coating can effectively improve the coating extraction capacity and selectivity.5.Using the self-made PDMS/Q[7]-OCH₂CH=CH₂ coating,establishing Fiber-SPMEGC-FID extraction detection of vegetables in the 10 kinds of common pesticide residue analysis method,systematically optimizing experimental factors on its extraction effect,the linear range of the analytical method was between30-10000?g L^-1 and the correlation coefficient ranged from 0.9816 to 0.9992.The detection limit was between 11.76 and 76.67?g L^-1,and the enrichment factor was between 14 and 79.The RSD% of the self-made coating was between 4.55% and9.28%,the RSD% of the daytime extraction was between 3.13% and 9.93%.The results showed that the average recoveries of 10 kinds of pesticides were between45.29% and 121.53%,RSD% was between 2.21% and 11.83%,and the recoveries of radish,cabbage,cucumber,lettuce leaves and tomato were evaluated by standard addition method.Indicating that the established analysis method was wide linear range,high accuracy,good precision and met the requirements of pesticide residues in vegetables.The method was established for the detection of 10 common pesticide residues in the actual sample,and the results were satisfactory.