High Sensitive Analysis Method Study Of Typical Antibiotics In Environmental Water By Capillary Electrophoresis

The pollution problem about antibiotics residues in the environment may lead to potential ecological risks and develop bacterial drug resistance.These harms may threaten human health,which have attracted public concern in recent years.In surrounding circumstances such as soil,sludge,surface water,underground water etc.,antibiotics residues were frequently detected.In our study,fluoroquinolones and sulfonamides antibiotics,as target analytes were analyzed by capillary electrophoresis(CE)with Photo-diode array detector.CE technique is effective and green,however,its low sensitivity limit its application for trace antibiotics analysis in the environment.To improve the sensitivity,online preconcentration technique such as PAEKI and offline pretreatment technique such as solid phase extraction(SPE)were combined for sensitivity improvement.This method can be a plausible route for trace antibiotics residue analysis.In chapter one,the production,usage and pollution situation was briefly introduced.And then the antibiotics categories for clinical and veterinary,the pollution sources of antibiotics in the environmental water and its environmental influence for animals and human health,the varieties of antibiotics residues in the environmental water and several analytical methods for antibiotics were elaborated in details.The principle,characters,separation modes,different detectors,online preconcentration techniques of CE and several pretreatment methods(especially solid phase extraction)were described.Finally,the content and significance of our study was stated.In chapter two,the determination method of four FQs(norfloxacin,ofloxacin,enrofloxacin and ciprofloxacin)and three SAs(sulfamethazine,sulfamethoxazole,sulfadiazine)antibiotics by capillary zone electrophoresis coupling to UV detector(CZE-UV)was developed.Due to different binding constant between methyl-beta-cyclodextrin(M-?-cyclodextrin)and antibiotics,certain concentration additive(M-?-cyclodextrin)was added into running buffer for achieving seven antibiotics baseline separation by CE.The p H,concentration of M-?-cyclodextrin and running buffer,separation voltage were optimized,and seven antibiotics can baseline separated in 15 min at optimal electrophoresis condition.The optimal electrophoresis condition was validation in linearity and repeatability,and the limit of detections were in the range of 0.20~0.40 mg/L.This method was applied for antibiotics residue analysis in tap,lake and river water.Antibiotic was not detected,which proved that antibiotics concentration was lower than 2mg/L.In chapter three,three injection modes: Hydrodynamic injection(HDI),Electrokinetic(EKI),Pressure assisted electrokinetic injection(PAEKI)were used to improve the sensitivity of seven antibiotics detection.The results showed that the enrichment factor of PAEKI was high in comparison to HDI and EKI modes and the LODs can reached to 1.96~4.06 ?g/L.The optimal electrophoresis condition of PAEKI was validation in linearity and repeatability,and applied for antibiotics residue analysis in tap,lake and river water.No antibiotic was detected in three environmental water samples.In chapter four,SPE technique was used for eliminating matrix disturbance in the environmental water and also for antibiotics enrichment.Three SPE columns were compared for extracting analytes in antibiotics solution.HLB column was chosen due to optimal extraction recovery.SPE parameters such as elute solvent species,dripping speed and volume were optimized.SPE was applied for spiked environmental water samples extraction(concentration was 0.01 mg/L for each antibiotic)and the recoveries were above 50%.SPE was applied for environmental water samples preconcentration(tap,lake and river water)and analyzed by CE-PAEKI.The results showed that several antibiotics were detected.In chapter five,the research project was summarized and further research was planned.In our study,seven antibiotics have been separated simultaneously,and the sensitivity of antibiotics by CE-PAEKI was improved by about 100-fold.Antibiotics were detected in environmental water samples combining CE-PAEKI with SPE techniques.In the following work,the extraction recovery and enrichment factor of SPE should be improved.Other online stacking method such as Electrokinetic supercharging should be developed for achieving sensitivity improvement by three orders of magnitude.The offline SPE and inline stacking techniques should be applied for more environmental water samples analysis.