| Phenolic pollutants are widely used in industry,and the produced industrial wastewater enters the environmental water source,causing serious pollution to the environment and increasing the ecological burden.Edible oil is polluted through accumulation of food chain and crop pollution,which exposes all organisms to phenolic compounds.Bisphenol and alkylphenol pollutants have the characteristics of environmental endocrine disturbance,which can cause teratogenesis,carcinogenesis and mutagenesis to organisms.They are highly fat soluble and can accumulate in the body.Even if the intake of trace level of phenolic pollutants will cause harm to human body.Therefore,it is necessary to develop environmentally friendly and simple detection methods that can simultaneously detect bisphenols and alkylphenols in water samples and edible oil samples.Due to the low content of the two types of phenolic pollutants in actual environmental samples and serious matrix interference,it is necessary to establish a new pretreatment method to purify,separate and enrich them.In order to meet the principles of green chemistry,new dispersive liquid-liquid microextraction(DLLME)technologies were established based on green solvent—ionic liquid(IL).Combined with high performance liquid chromatography,the methods for the detection of bisphenol and alkylphenol in water samples and edible oil samples were established,and its extraction mechanism were discussed.In the first chapter,the pollution status and hazards of phenolic pollutants were mainly summarized.The instrumental detection and pretreatment methods of phenolic pollutants were discussed,and the DLLME technology was emphasized.Finally,the background and content of this research were explained.In the second chapter,imidazolium IL was used as extractants,and five phenolic pollutants(bisphenol A,bisphenol B,bisphenol AF,4-tert-octylphenol,nonylphenol)were studied.Ultrasonic-assisted DLLME was established as the pretreatment method,combined with high performance liquid chromatography and fluorescence detection.In this experiment,the effects of different anions of IL on the extraction effect were compared and the reasons were analyzed.The influence factors of IL,dispersant,electrolyte,ultrasonic time,solution p H,centrifugal speed and time were studied.Under the optimal experimental conditions,each analyte had a good linear relationship with the peak area within its concentration range(r≥0.9980),and the limit of detection(LOD,S/N=3)range for the analytes was 0.058-0.21 μg/L,The relative standard deviation(RSD)was less than 5.52%,the extraction efficiency were over94.9%,and the range of recovery rate of environmental water samples was 90.3%-108%.In the third chapter,a method based on pyrrolidinium IL-DLLME technology combined with high performance liquid chromatography to detect phenolic pollutants was established to expand the application of IL.The ability of pyrrolidinium cation IL to detect bisphenol and alkylphenol pollutants was studied.By selecting IL with low viscosity and strong hydrophobicity as the extractant,it interacted with bisphenol and alkylphenol pollutants to obtain high extraction efficiency and enrichment factor.It solved the current research situation that the application of IL-DLLME technology was limited to the use of imidazolium zole IL as extractant.In the experiment,1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide was used as the extractant,methanol was used as the dispersant.The extractant formed tiny droplets with the assistance of ultrasound.The experimental parameters such as the dosage of IL and dispersant,ultrasonic time,salt type and dosage,and p H of the solution were explored.The limits of detection of the method were0.051-0.22 μg/L.The precision of the method was good,and the relative standard deviations(RSDs)of inter-day and intra-day were less than5.65%.The method have been applied to the separation and determination of five phenolic pollutants in environmental water samples.Satisfactory results have been obtained with the recoveries of93.7%-109%.The experimental results showed that the method was economical and environmentally friendly.Pyrrolidinium IL was used as the extractant to extract phenolic pollutants to obtain good extraction effect,which provided a new idea for expanding the application of IL in the extraction of organic pollutants in DLLME technology.In the fourth chapter,a method based on ionic liquid dispersive liquid-liquid microextraction-high performance liquid chromatography for the determination of five phenolic pollutants in edible oils was established.Bisphenols and alkylphenols are different in polarity.Sodium hydroxide solution was added to convert the analytes into ionic form.By comparing the extraction effects of five kinds of ionic liquids[1-Butyl-3-methylimidazolium tetrafluoroborate,1-Butyl-3-methylimidazolium hexafluorophosphate,1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imine,1-Ethyl-3-methylimidazolium bis(fluorosulfonyl)imide,1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide],alcohols and acetonitrile,1-Butyl-3-methylimidazolium tetrafluoroborate with stronger hydrophilicity and acetonitrile were selected as extractants to meet the simultaneous detection of two kinds of phenolic pollutants.The recovery rate of this method was in the range of 90.0%-109%,the matrix effect was negligible,and the system tolerance was high.Under the optimal experimental conditions,the five analytes showed good linearity(r ≥0.9966)within the concentration range studied in the experiment,and the limits of detection were 0.360-0.550 μg/kg,which met the actual sample detection requirements.The precision of the method was good,and the RSD of both intraday and interday were less than 5.61%(n=6).This method have been successfully applied to the separation,enrichment and determination of five phenolic pollutants in edible oils,and the results met the requirements of analytical chemistry. |
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