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Study On The Determination Of Trace Pharmaceutically Active Compounds And Their Distribution Features In Wuhan City

Posted on:2023-05-07Degree:DoctorType:Dissertation
Country:ChinaCandidate:X Q LeiFull Text:PDF
GTID:1521306827451554Subject:Geology
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With the rapid development of economy and the continuous improvement of people’s health awareness,pharmaceutically active compounds(PhACs),known as emerging pollutants with potential environmental threatens,have attracted global attention.As an important critical city along the Yangtze River Economic Belt,Wuhan hosts rich lakes,reservoirs and ponds.The large amount and widely distributed lakes serve as the main drinking water source for Wuhan residents.With the rapid development of health,biological,medicine industry,agricultural,livestock breeding and the outbreak of COVID-19 as well as the increasing consumed dosage of PhACs including antibiotics,cardiovascular drugs,antipyretic analgesic anti-inflammatory drug and other PhACs increased significantly.The lake water environment encounters are facing serious PhACs pollution.However,due to the relatively low concentration of PhACs in lake water and relatively high limitation of detection of the existing techniques,the current researches on PhACs majorly focus on their distribution in lake sediments with high concentrations.Although the concentration of PhACs in lake water is relatively low,it is necessary and important to study the concentration distribution and environmental factors of PhACs in lake water,which is the main living space of a large number of organisms and the drinking water source of residents.Thereby,to achieve a foundmental understanding of the PhACs distributions in surface water,it is necessary to develop effective approaches to enrich and separate trace PhACs from natural water,followed with the establishment of reliable and accurate analytic methods.Consequently,it is thus possible to determine the concentrations and their distribution of PhACs in Wuhan lakes,and thereafter provide applicable technical schemes for controlling the PhACs pollution.The present thesis takes the goal of sensitive analysis of trace PhACs in lakes in Wuhan urban area as the research object,adopting solid phase extraction(SPE)which has the advantages of simple operation,low organic solvent consumption,high sample recovery,easy automation and low cost,as the pre-treatment method.Combined magnetic solid phase extraction with high performance liquid chromatography-triple quadrupole mass spectrometry,a series of new methods have been developed for the determination of PhACs.Using magnetic nitrogen doped porous carbon(MNPC)as solid phase extraction material,the temporal and spatial distribution characteristics of PhACs in lakes and rivers in Wuhan city were investigated.The main understanding of this thesis is as follows:1.Magnetic nitrogen doped porous carbon solid phase extraction material was synthesized by solvent-free in-situ polymerization in one step.Hierarchical nitrogen-doped porous carbon(NPC)was synthesized by solvent-free in-situ polymerization using high nitrogen content melamine as monomer.Adsorption experiments show that nitrogen doping can greatly improve the adsorption performance of IBP.MNPC was further prepared by introducing Fe Cl3as magnetic source in the above synthesis.The structure,morphology and specific surface area of MNPC were characterized by X-ray diffraction,N2adsorption-desorption curve and magnetic intensity characterization.MNPC can quickly capture trace PhACs from water and be isolated under an external magnetic field,overcoming the difficulty of recycle and reuse.Metoprolol(MTP)as the target analyte,the optimal sample MNPC-1 could reach adsorption equilibrium for MTP within 60 min,showing good enrichment performance.The adsorption capacity is highly as 25.2 mg/g,suggesting the good enrichment performance.Using MNPC for MSPE of PhACs displayed many advantages,such as simple operation,low organic solvent consumption,high sample recovery,high separation and enrichment efficiency,easy automation and low cost.It is promising for the pre-treatment of trace PhACs in natural water.2.Establishing a method for separation,enrichment and determination of PhACs in water by MSPE-HPLC-MS/MS.Four representative PhACs including MTP,Irbesartan(IRB),Carbamazepine(CBZ)and Sulfamethoxazole(SMZ)were selected as target analytes.Using MNPC-1 as MSPE adsorbent,the factors affecting extraction efficiency were investigated and optimized in detail.Under the optimized chromatography-mass spectrometry conditions,a method for simultaneous determination of multiple PhACs based on HPLC-MS/MS was established and the relevant methodology was investigated.The results showed that the method had excellent performance in low LODs(0.027-0.081μg/L)and wide linear range(0.1-100μg/L,R2=0.9890-0.9987),and the spiked recoveries ranged from 87.3-99.7%.Compared with the traditional commercial HLB column pretreatment,this method has the advantages of fast analysis speed,less consumption of organic reagents,high sensitivity,low detection limit,and has a good application potential for the analysis and detection of PhACs in environmental water.3.Trace PhACs in Wuhan lakes and rivers were determined by MSPE-HPLC-MS/MS method,and the spatial and temporal distribution characteristics of PhACs in Wuhan city were described.Using the developed MSPE-HPLC-MS/MS analysis method,ten PhACs as MTP and IRB with large dosage and high social concern were used as the target analytes to analyze and test PhACs in typical lakes in Wuhan city and their sources were preliminarily analyzed.The pollution level of PhACs in lakes and rivers in Wuhan city and the content of PhACs in surface water of seperate water sources are different,which are mainly related to the source and degradation process.Based on the concentration distribution characteristics of the target compounds from existing studies and data obtained in this study,it was found that PhACs in water mainly came from human activities,such as domestic sewage,medical wastewater and fishery farming.The vertical and seasonal distribution characteristics of PhACs in surface water were systematically analyzed.The results showed that the concentration of target compounds in surface water was not only affected by photodegradation,microbial degradation and other factors,but also related to climatic factors such as temperature and rainfall.Due to the influence of photodegradation,microbial degradation and sampling temperature,metronidazole has low concentration on the surface.But with the increase of sampling depth,the concentration increases.The concentration of MTP,IRB,sulfamethoxazole,carbamazepine,metformin,erythromycin,clarithromycin and olanzapine reached the maximum at the surface,and decreased with the change of sampling depth,althrough the change was small.In addition,the occurrence of PhACs had obvious seasonal variation:the total concentration of PhACs in March(11.10-132.89 ng/L)was significantly higher than that in August(8.10-122.19 ng/L).The persistence of PhACs in water environment showed a typical trend of“high in spring and low in summer”.
Keywords/Search Tags:PhACs, Magnetic porous carbon material, Distribution characteristics, Lakes and rivers
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