Study On Pollution Characteristics And Source Identification Of Atmospheric Amines Within Typical Regional In China

Amine is one of the important nitrogen-containing organic compounds in the atmosphere,which affects human health and actively participates in physical and atmospheric chemical reactions,such as the formation of new particles and brown carbon.Amines in the atmosphere come from a wide range of sources,including oceans,biomass combustion,some geological activities,fish processing,domestic sewage and waste composting.In addition,with the increasing attention to climate issues,amines are widely used as effective absorption solvents to capture carbon dioxide in the combustion process to reduce greenhouse gas emissions.Therefore,carbon sequestration is considered to be another man-made source of atmospheric amines.Gaseous amines,including methylamine（MA）,dimethylamine（DMA）and trimethylamine（TMA）,are highly dangerous and toxic and usually have an unpleasant smell.Although the concentration of amines is low under typical environmental concentrations,its effect on atmospheric aerosols can not be ignored.Frequent exposure to amines may also increase human health risks.In this study,through the establishment of simultaneous collection and qualitative and quantitative analysis methods of gaseous and particulate amines,the pollution characteristics of amines in atmospheric particulate matter in six regions in China were studied to understand the pollution characteristics of atmospheric amines in different latitudes.Then,in order to further explain the pollution characteristics of amines in particulate matter in different regions,the composition and content characteristics of amine compounds from three typical amine emission sources are analyzed to understand the possible impact of different types of amine sources on regional amine pollution characteristics.Then,the gas particle distribution mechanism of amines in three representative cities was deeply studied.Through the comparative analysis between the gas particle distribution of amines in the actual environment and the theoretical inference,this thesis explores the influencing factors of the gas particle distribution of regional amines,so as to explore the law of the pollution characteristics of amines in different regions from the perspective of atmospheric heterogeneous chemistry of amines.We have established a new gas chromatography-mass spectrometry method which,based on benzene sulfonyl chloride derivatization for simultaneous collection and analysis of gaseous and particulate amines,was established.The results show that the method can be successfully used for the qualitative and quantitative analysis of 14 amines in particle and gaseous samples.The optimum conditions for derivatization are as follows:for all samples,the dosage of benzenesulfonylchloride（BSC）is 200μL is the best dosage.For particle and gaseous samples,the optimum dosage of Na OH is 200μL and 1000μL,respectively。The absorption efficiency of acidified filters is 95.8%,and the particles on the first filter have little effect on the collection of gaseous amines（only 1.7%）.The working curve R~2 range of this method is 0.992-0.998 and 0.993-0.999,both of which are greater than 0.99;The detection limits and quantitation limits of 14 amines were 0.041-0.421 and 0.163-1.68μg/m L,respectively;The recoveries of 14 amines under three concentration gradients were 65.8%-133%and 68.0%-180%,and the relative standard deviation（RSD）was less than 30%.The qualitative and quantitative analysis of atmospheric particulate matter and inorganic compositions and amines in 6 regions in China.On a large spatial scale,the total concentration of amines in different regions of China shows the law of Wuhan（321.94±134.85 ng/m~3）>Shantou（283.55±194.08 ng/m~3）>Qingdao（234.80±129.22 ng/m~3）>Guangzhou>Taiyuan（116.47±66.58 ng/m~3）.On a small spatial scale,the total amount of amines in the two sampling points in Guangzhou is similar（157.69±127.74 and 151.01±95.80 ng/m~3）,but the composition of various amines is very different.The p H of particles in each area is in the range of-0.18～-0.79,and the water content is range of 15.46-103.64μg/m~3,the total concentration of four main inorganic ions（7）^-,₄^2-,₃^-and₄⁺)is within 7.96-61.96μg/m~3.Comparing the properties of particles,the pollution characteristics of inorganic ions and organic amines,it was found that the morphology of amines in the particle phase is similar to₄⁺competitive reaction and the trend of entering the particle phase are different,that is,the way and degree of amines entering the particle phase are different in different regions.Taking Guangzhou,Wuhan and Taiyuan as examples,the gas particle distribution fractions of amines predicted by the theoretical model and observed in practice were compared and analyzed.The results showed that the total concentration of gaseous amines in different regions showed the law of Guangzhou>Wuhan>Taiyuan,and the gas particle distribution fraction organic amines in three regions showed the law of Taiyuan>Wuhan>Guangzhou.It is found that the reaction of amines with acids at the gas-liquid interface of particulate matter contributes the most to the enrichment organic amines in particulate matter compared with physical adsorption and direct dissolution.The influence of gas particle distribution behavior of atmospheric amines on their regional pollution characteristics is reflected in the influence of the reaction degree between amines and acids on their enrichment in the particulate phase.Due to different factors such as ambient temperature,humidity and concentration of related acid gases in different regions,the reaction degree between amines and acids is different,resulting in the difference of regional amine pollution characteristics.In addition,through the analysis of three typical amine emission sources,it was found that the total concentration of organic amine in three typical amine sources（aquaculture source,marine source and coal-fired industrial park）showed the law of aquaculture source>coal-fired industrial park>marine source,and the components of various amines in the three amine sources are also significantly different.It shows that the type and quantity of organic amine sources in different regions will also lead to the difference of regional organic amine pollution characteristics.To sum up,there are obvious differences in the characteristics of atmospheric amine pollution in different regions of China,which are derived from the differences of atmospheric air particle distribution behavior of amines in different regions and the impact of different types of amine emission sources.Therefore,a more comprehensive study on the atmospheric behavior and source analysis of amines will help to better realize the pollution control of amines in the future.