| The survey of The Rural Green Paper: Analysis and Prediction of Rural Economic Situation(2015~2016)indicates that in order to increase production as much as possible in China,the phenomenon of agricultural producers abusing pesticide is quite common nationwide,of which the large amount of abusing quaternary ammonium pesticides has caused environment pollution,food safety and public security and some other issues,which should not be ignored.Quaternary ammonium pesticides are strongly alkaline ionic compounds,which couldn't be analyzed directly by gas chromatography or require a lot of procedures and the accuracy and sensitivity are not desirable if using the technique indirectly;Although the sensitivity of the method of liquid chromatography/mass spectrometry is superior to other methods,but there is no good column for baseline separation between paraquat and diquat on the market at present,and the compounds have potential damage to the mass spectrometry.However,capillary electrophoresis is suitable for the analysis of ion compounds,and its efficient separation ability can easily achieve the baseline separation of paraquat and diquat.The thesis' research includes two parts: the first part examined and optimized the conditions of two kinds online enrichment technology of capillary electrophoresis and solid phase extraction conditions as well on the basis of predecessors' research.On this basis,the author observes the common poisoning matrixes of quaternary ammonium herbicides such as drinking water,pond water,urine,blood and so on via suitability test approaches.And the finally established method has achieved the spontaneous separation of three quaternary ammonium herbicides and high sensitive detection of them among the fish pond water,urine and whole blood in biological sample.The second part is to study a new intelligent biomimetic sensor---molecular imprinted photonic crystal hydrogel,which makes it possible that the on-site chlormequat pesticides in environmental water samples be detected rapidly.The major researches includes the following:First part: the application of online and offline enrichment technology to detect quaternary ammonium herbicides in water,urine and the whole blood samples.1.It investigated and optimized the on-line electrophoresis conditions,and established the method of Field-Amplified Sample Stacking(FASS)and Sweeping-Micellar Electrokinetic Chromatography(Sweeping-MEKC)on detection of the trace quaternary ammonium herbicides in drinking water and pond water,and optimized the solid phase extraction conditions as well;To increase the sensitivity of trace quaternary ammonium pesticides in environmental water samples,it combined the off-line(the solid phase extraction)and on-line(enrichment of electrophoresis)enrichment technology together.In Sweeping-MEKC electrophoresis analysis,it adopted long time pressure injection method to avoid the adverse impact of ion discrimination effect by electrophoretic injection,which achieved the baseline separation of paraquat and diquat and implemented the determination of the three quaternary ammonium herbicides spontaneously.The method is of good sensitivity,the detection limit(LOD)of paraquat,diquat and difenzoquat in the pond water are about 0.07ng/mL,0.05ng/mL and 0.02ng/mL respectively,lowering than the limit standard of paraquat and diquat in drinking water stipulated by the US Environmental Protection Agency and the European Union.It can be practically applied in the analysis of quaternary ammonium herbicides in environmental water and agricultural pond water.2.On the basis of the optimized capillary electrophrosis enrichment technology and according to the urine features,the paper established a FASS detection method for quaternary ammonium herbicides in urine samples by direct dilution of the urine.The method can quickly detect paraquat and diquat in urine samples,and the detection limits are 0.4?g/mL and 0.9?g/mL,which can be applied to the rapid detection of human quaternary ammonium herbicides poisoning cases,as well as monitoring concentration changes in clinical in order to provide an important reference for prognostic treatment.However,the endogenous interference peak existing in the urine covered the peak of difenzoquat.In order to detect trace difenzoquat in urine,the off-line enrichment of SPE and Sweeping-MEKC was used combined.The detection limits of paraquat,diquat and difenzoquat are reached to 10ng/mL,15ng/mL and 5ng/mL respectively,showing the method was not only eliminated endogenous interference on difenzoquat detection,but also detected the three quaternary ammonium herbicides at the same time,and greatly improved the detection limit of them as well.3.Protein precipitation and protein precipitation enrichment method,combined wirh fieldamplified sampling stacking of capillary zone electrophoresis(FASS-CZE)was developed for online concentration of paraquat,diquat and difenzoquat in human whole blood.Firstly,the stability and matrix effect of quaternary ammonium herbicides in human whole blood were examined,and the pretreatment conditions were optimized.With the method,the detection limit of paraquat,diquat and difenzoquat in human whole blood were 0.3?g/mL,0.3?g/mL and 0.8?g/mL respectively.The pretreatment is simple and rapid,which can be used in fast detection of quaternary ammonium herbicides in blood samples.Secondly,protein precipitation enrichment combined with field amplification enrichment method was applied in the analysis of whole blood sample.The detection limit of paraquat,diquat and difenzoquat were 0.1?g/mL,0.1?g/mL and 0.5?g/mL respectively.Finally,to further increase the sensitivity of theherbicides in the whole blood,off-line of SPE and Sweeping-MEKC method was combined,the detection limit of paraquat,diquat and difenzoquat were reached to 25ng/mL,20ng/mL and7ng/mL respectively.The three methods developed in this section may meet the demands in public security and clinical practices for different situations and requirements.Second part: the application of molecularly imprinted fast detection technology in determination chlormequat in water samples.Molecularly imprinted photonic crystal hydrogel technology is a new type of intelligent bionic type rapid detection technology.Compared with enzyme-linked immunoassay,molecularly imprinted polymers(MIPS)has the similar antibody specificity,besides,it has the characteristics of better corrosion resistance because of its artificial chemical synthesis.On the basis of previous studies,the paper prepared the chlormequat molecularly imprinted photonic crystal hydrogel sensor for the first time.In the preparation,optimized synthetic ingredients(monomer,crosslinking agent,solvent,etc.)of the polymer were screened out and the component ratios were adjusted in order to improve the physical and chemical performance of the polymer and its gel internal inverse opal structure.The molecularly imprinted polymer film with the specific identification in the molecular recognition process causes the internal inverse opal structure parameters change,and the diffraction of light can be observed by naked eye,which achieved the bionic intelligent rapid detection.The sensitivities,specificities and adsorption characteristics of the imprinted films were characterized by Scatchard analysis,infrared spectroscopy and recognition mechanism.The results showed that the film had the strong anti-interference ability,quick response.The minimum detection of the film reached to100 pg/mL,and it could be repeatedly used without affecting the efficiency.There has no literature concerned the chlormequat enzyme-linked immunosorbent technology and molecularly imprinted photonic crystal hydrogel technology at home and abroad so far.And the performance of the chlormequat molecularly imprinted photonic crystal hydrogel was excellent in the research that can be applied to rapid screening in the site.It also demonstrates a good developing and application prospects. |
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