石油是一种复杂体系,研究石油分子组成是分析化学领域的经典难题.近年来,傅里叶变换离子回旋共振质谱技术(Fourier transform ion cyclotron resonance mass spectrometry,FT-ICR MS)的发展,为从分子水平认识石油组成提供了机会,引起了...石油是一种复杂体系,研究石油分子组成是分析化学领域的经典难题.近年来,傅里叶变换离子回旋共振质谱技术(Fourier transform ion cyclotron resonance mass spectrometry,FT-ICR MS)的发展,为从分子水平认识石油组成提供了机会,引起了石油化学界的高度关注,并被期待能在石油、石化领域的相关研究中实现重大突破.本文从质谱分辨率和电离技术方面介绍了石油样品的分析需求,总结了近几年基于FT-ICR MS技术对石油分子组成的研究进展,分析了其在应用中存在的关键技术问题及下一步研究方向,并对FT-ICR MS的发展前景给予展望.展开更多
A data processing combination of manual and automatic steps for mass peaks identification of a coking gas oil was illustrated.Some representative compounds were identified by manual process.A program was performed to ...A data processing combination of manual and automatic steps for mass peaks identification of a coking gas oil was illustrated.Some representative compounds were identified by manual process.A program was performed to search the various types with the same hetero-atoms(familes-class,NnSsOo)but different rings plus double bonds(R+DB)value(Z in CcH2c+ZNnOoSs),then,alkylation series of each types were revealed by multiplying each mass by 14.00000 in Kendrick mass scale.Finally,isotope groups of each identified peaks were picked up respectively.The method is appropriate to the data analysis of FT-ICR MS spectra with a poor mass accuracy.展开更多
The origin of the unusually high dibenzothiophene （DBT） concentrations in Lower Ordovician oils from the Tazhong Uplift,Tarim Basin was studied by Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR...The origin of the unusually high dibenzothiophene （DBT） concentrations in Lower Ordovician oils from the Tazhong Uplift,Tarim Basin was studied by Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）.The most abundant sulfur compounds in the oils are S 1 species with doublebond equivalent （DBE） values of 1-19 and 11-48 carbon atoms.The range of the number of carbon atoms in the sulfur compounds detected by the FT-ICR MS （S 1 species with DBE=9） is about ten times larger than that for sulfur compounds detected by GC/MS （DBTs）.This suggests that FT-ICR MS is a much better approach than GC/MS for characterization of DBTs in crude oils.The abundance of S 1 species with DBE=1-8 decreased with increasing thermal maturity,while the abundance of S 1 species with DBE=9 （primarily DBTs） increased.Therefore,thermal maturity is an important factor in the formation of oils with high DBT concentrations.Unusually high abundances of S 1 species with low DBE values （1-8）,which include sulfide,thiophene and benzothiophene,were observed in several oils,especially the TZ83 （O 1） oil with high or very high thermal maturity.Thermochemical sulfate reduction （TSR） was thought to be the reason for the high abundance of these low DBE compounds in deep reservoirs,and thermochemical sulfate reduction could affect the distribution and composition of DBTs in the oils.According to the results of FT-ICR MS analysis,there are no signs that TSR is occurring or has occurred recently for most of the Lower Ordovician oils.展开更多
Municipal wastewater reclamation is becoming of increasing importance in the world to solve the problem of water scarcity. A better understanding of the molecular composition of effluent organic matter（Ef OM） in the...Municipal wastewater reclamation is becoming of increasing importance in the world to solve the problem of water scarcity. A better understanding of the molecular composition of effluent organic matter（Ef OM） in the treated effluents of municipal wastewater treatment plants（WWTPs） is crucial for ensuring the safety of water reuse. In this study, the molecular composition of Ef OM in the secondary effluent of a WWTP in Beijing and the reclaimed water further treated with a coagulation–sedimentation–ozonation process were characterized using a non-target Fourier transform ion cyclotron resonance mass spectrometry（FT-ICR MS） method and compared to that of natural organic matter（NOM） in the local source water from a reservoir. It was found that the molecular composition of Ef OM in the secondary effluent and reclaimed water was dominated by CHOS formulas, while NOM in the source water was dominated by CHO formulas. The CHO formulas of the three samples had similar origins. Anthropogenic surfactants were responsible for the CHOS formulas in Ef OM of the secondary effluent and were not well removed by the coagulation-sedimentation-ozonation treatment process adopted.展开更多
The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier tran...The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.展开更多
The basic-nitrogen aromatic compounds in feedstocks and liquid products from the micro-reactor and soluble components of coke obtained during fluid catalytic cracking （FCC） process were analyzed by the micro-electro...The basic-nitrogen aromatic compounds in feedstocks and liquid products from the micro-reactor and soluble components of coke obtained during fluid catalytic cracking （FCC） process were analyzed by the micro-electrospray ioniza- tion （ESI） 9.4T Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） with an average mass resolving power of 300 000 at a mass range of 100--1 200. The analytical results revealed that the coker gas oil （CGO） contained a higher abundance of basic-nitrogen aromatic compounds with the type of-SN to -9N compared with those in deasphalted oil （DAO） and mixed FCC feedstock. After catalytic cracking, the abundance of lowly condensed basic-nitrogen aromatic compounds was much less than those of highly condensed aromatics in the liquid products, with the carbon number mainly ranging from 6 to 25 and the average carbon number of the side-chains equating to 1--5. On the contrary, with respect to the soluble components of coke, the abundance of lowly condensed basic-nitrogen aromatic compounds was more than those of highly condensed aromatics, and the carbon number ranged from 12 to 30, which was much smaller than that of the mixed FCC feedstock but slightly larger than that of the cracked liquid products. These results have provided some fundamental information on FCC process.展开更多
Using heptane, toluene, and tetrahydrofuran （THF） as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both as...Using heptane, toluene, and tetrahydrofuran （THF） as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both asphaltene and its fractions were ana- lyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry （ESI FT-ICR MS）. The application of UV-vis spectrometer in characterizing asphaltene composition and measuring asphaltene concentration was discussed. About 11.9 wt% asphaltene components adsorbed permanently on silica gel in the extrography column after exces- sive elution with various solvents. In negative FT-ICR MS, the mass spectra show that acidic and neutral nitrogen-containing compounds such as N1 and NIS1 mainly existe in the first three less polar fractions, while oxygen-containing compounds such as 02, O2S, O2S2, 03, and 04 show high relative abundance in more polar fractions. These results suggest oxygen-containing compounds have stronger adsorption ability with silica gel. It was observed that the double bond equivalence （DBE） distribu- tion of N1 class species in the fractions shifted to higher values while the carbon number shifted to smaller numbers as polarity of fractions increased. This indicates that acidic and neutral Nl compounds with longer carbon chain and less aromaticity have less polarity compared with those with shorter carbon chain and stronger aromaticity. UV-vis absorbance indicats that fractions containing the most aromatic and most polar asphaltene have better absorbance at long wavelength, while the fractions that consist of least aromatic and least polar asphatlenes show high absorbance at short wavelength.展开更多
车用新鲜及废润滑油样品的傅里叶变换红外光谱(FT-IR)表明,两者中均存在羧基及羟基官能团,即存在酸性组分。利用具有超高分辨率的负离子电喷雾-傅里叶变换离子回旋共振质谱仪(negative-ion ESI FT-ICR MS)分析了车用新鲜及废润滑油中酸...车用新鲜及废润滑油样品的傅里叶变换红外光谱(FT-IR)表明,两者中均存在羧基及羟基官能团,即存在酸性组分。利用具有超高分辨率的负离子电喷雾-傅里叶变换离子回旋共振质谱仪(negative-ion ESI FT-ICR MS)分析了车用新鲜及废润滑油中酸性化合物的组成及分布。结果表明,从新鲜润滑油中鉴定出的酸性化合物主要为O3、O1及O2类,而从废润滑油中鉴定出的酸性化合物则主要为O3、O2、O4及O1类。经对比分析可知,新鲜润滑油中的酸性化合物在废润滑油中均存在,其种类及所占比例基本未发生变化,但绝对含量不同;废润滑油中新产生的O3、O2及O1类酸性化合物种类较多,但其所占比例较小;车用新鲜与废润滑油中酸性组分的显著差异在于后者中产生了前者所没有的O4类化合物,且所占比例较大。展开更多
This paper examined the bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds in Sudan heavy petroleum fraction. Both broadband and quadrupole isolation modes positive-ion electrospray ...This paper examined the bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds in Sudan heavy petroleum fraction. Both broadband and quadrupole isolation modes positive-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） coupled with collision induced dissociation （CID） tech- niques were used to characterize a low sulfur crude oil derived vacuum residuum （VR）. The appropriate CID operating condi- tion was selected by comparing the molecular weight distributions of the basic nitrogen compounds under various CID operat- ing conditions. Both odd- and even-electron fragment ions were observed from the mass spectrum, indicating that the hetero- lyric and homolytic bond cleavages occurred simultaneously during the CID process. The odd-electron fragment ions were predominant in each class species, indicating preferential heterolytic bond cleavages. At the optimal CID condition, the alkyl groups decomposed deeply and just left the aromatic cores of the nitrogen compounds. No Significant variation in double bond equivalent （DBE） value was observed between the fragment and parent ions, revealing that the domination of single core structure.展开更多
UV/chlorine process,as an emerging advanced oxidation process(AOP),was effective for removing micro-pollutants via various reactive radicals,but it also led to the changes of natural organic matter(NOM)and formation o...UV/chlorine process,as an emerging advanced oxidation process(AOP),was effective for removing micro-pollutants via various reactive radicals,but it also led to the changes of natural organic matter(NOM)and formation of disinfection byproducts(DBPs).By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS),the transformation of Suwannee River NOM(SRNOM)and the formation of chlorinated DBPs(Cl-DBPs)in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark chlorination.In comparison to dark chlorination,the involvement of Cl O·,Cl·,and HO·in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity(AI mod)value and DBE(double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic compounds.Meanwhile,more compounds which contained only C,H,O,N atoms(CHON)were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions.A total of 833 compounds contained C,H,O,Cl atoms(CHOCl)were observed after the UV/chlorine AOP,higher than 789 CHOCl compounds in dark chlorination,and one-chlorine-containing components were the dominant species.The different products from chlorine substitution reactions(SR)and addition reactions(AR)suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher aromaticity.Post-chlorination further caused the cleavages of NOM structures into small molecular weight compounds,removed CHON compounds and enhanced the formation of Cl-DBPs.The results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.展开更多
文摘石油是一种复杂体系,研究石油分子组成是分析化学领域的经典难题.近年来,傅里叶变换离子回旋共振质谱技术(Fourier transform ion cyclotron resonance mass spectrometry,FT-ICR MS)的发展,为从分子水平认识石油组成提供了机会,引起了石油化学界的高度关注,并被期待能在石油、石化领域的相关研究中实现重大突破.本文从质谱分辨率和电离技术方面介绍了石油样品的分析需求,总结了近几年基于FT-ICR MS技术对石油分子组成的研究进展,分析了其在应用中存在的关键技术问题及下一步研究方向,并对FT-ICR MS的发展前景给予展望.
文摘A data processing combination of manual and automatic steps for mass peaks identification of a coking gas oil was illustrated.Some representative compounds were identified by manual process.A program was performed to search the various types with the same hetero-atoms(familes-class,NnSsOo)but different rings plus double bonds(R+DB)value(Z in CcH2c+ZNnOoSs),then,alkylation series of each types were revealed by multiplying each mass by 14.00000 in Kendrick mass scale.Finally,isotope groups of each identified peaks were picked up respectively.The method is appropriate to the data analysis of FT-ICR MS spectra with a poor mass accuracy.
基金funded by the Natural Science FundingCouncil of China(Grant No.#40973031)the Foundationof State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(No.PRPJC2008-02)Natural Science Research Council of China(China 973 National Key Research and Development Program 2011CB201102)
文摘The origin of the unusually high dibenzothiophene （DBT） concentrations in Lower Ordovician oils from the Tazhong Uplift,Tarim Basin was studied by Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）.The most abundant sulfur compounds in the oils are S 1 species with doublebond equivalent （DBE） values of 1-19 and 11-48 carbon atoms.The range of the number of carbon atoms in the sulfur compounds detected by the FT-ICR MS （S 1 species with DBE=9） is about ten times larger than that for sulfur compounds detected by GC/MS （DBTs）.This suggests that FT-ICR MS is a much better approach than GC/MS for characterization of DBTs in crude oils.The abundance of S 1 species with DBE=1-8 decreased with increasing thermal maturity,while the abundance of S 1 species with DBE=9 （primarily DBTs） increased.Therefore,thermal maturity is an important factor in the formation of oils with high DBT concentrations.Unusually high abundances of S 1 species with low DBE values （1-8）,which include sulfide,thiophene and benzothiophene,were observed in several oils,especially the TZ83 （O 1） oil with high or very high thermal maturity.Thermochemical sulfate reduction （TSR） was thought to be the reason for the high abundance of these low DBE compounds in deep reservoirs,and thermochemical sulfate reduction could affect the distribution and composition of DBTs in the oils.According to the results of FT-ICR MS analysis,there are no signs that TSR is occurring or has occurred recently for most of the Lower Ordovician oils.
基金supported by the National Natural Science Foundation of China(Nos.21377150 and 51578530)
文摘Municipal wastewater reclamation is becoming of increasing importance in the world to solve the problem of water scarcity. A better understanding of the molecular composition of effluent organic matter（Ef OM） in the treated effluents of municipal wastewater treatment plants（WWTPs） is crucial for ensuring the safety of water reuse. In this study, the molecular composition of Ef OM in the secondary effluent of a WWTP in Beijing and the reclaimed water further treated with a coagulation–sedimentation–ozonation process were characterized using a non-target Fourier transform ion cyclotron resonance mass spectrometry（FT-ICR MS） method and compared to that of natural organic matter（NOM） in the local source water from a reservoir. It was found that the molecular composition of Ef OM in the secondary effluent and reclaimed water was dominated by CHOS formulas, while NOM in the source water was dominated by CHO formulas. The CHO formulas of the three samples had similar origins. Anthropogenic surfactants were responsible for the CHOS formulas in Ef OM of the secondary effluent and were not well removed by the coagulation-sedimentation-ozonation treatment process adopted.
基金financially supported by the National Key Basic Research Development Program "973" Project (2006CB202501)
文摘The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.
基金supported by the National Basic Research Program of China (2010CB226901)
文摘The basic-nitrogen aromatic compounds in feedstocks and liquid products from the micro-reactor and soluble components of coke obtained during fluid catalytic cracking （FCC） process were analyzed by the micro-electrospray ioniza- tion （ESI） 9.4T Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） with an average mass resolving power of 300 000 at a mass range of 100--1 200. The analytical results revealed that the coker gas oil （CGO） contained a higher abundance of basic-nitrogen aromatic compounds with the type of-SN to -9N compared with those in deasphalted oil （DAO） and mixed FCC feedstock. After catalytic cracking, the abundance of lowly condensed basic-nitrogen aromatic compounds was much less than those of highly condensed aromatics in the liquid products, with the carbon number mainly ranging from 6 to 25 and the average carbon number of the side-chains equating to 1--5. On the contrary, with respect to the soluble components of coke, the abundance of lowly condensed basic-nitrogen aromatic compounds was more than those of highly condensed aromatics, and the carbon number ranged from 12 to 30, which was much smaller than that of the mixed FCC feedstock but slightly larger than that of the cracked liquid products. These results have provided some fundamental information on FCC process.
文摘Using heptane, toluene, and tetrahydrofuran （THF） as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both asphaltene and its fractions were ana- lyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry （ESI FT-ICR MS）. The application of UV-vis spectrometer in characterizing asphaltene composition and measuring asphaltene concentration was discussed. About 11.9 wt% asphaltene components adsorbed permanently on silica gel in the extrography column after exces- sive elution with various solvents. In negative FT-ICR MS, the mass spectra show that acidic and neutral nitrogen-containing compounds such as N1 and NIS1 mainly existe in the first three less polar fractions, while oxygen-containing compounds such as 02, O2S, O2S2, 03, and 04 show high relative abundance in more polar fractions. These results suggest oxygen-containing compounds have stronger adsorption ability with silica gel. It was observed that the double bond equivalence （DBE） distribu- tion of N1 class species in the fractions shifted to higher values while the carbon number shifted to smaller numbers as polarity of fractions increased. This indicates that acidic and neutral Nl compounds with longer carbon chain and less aromaticity have less polarity compared with those with shorter carbon chain and stronger aromaticity. UV-vis absorbance indicats that fractions containing the most aromatic and most polar asphaltene have better absorbance at long wavelength, while the fractions that consist of least aromatic and least polar asphatlenes show high absorbance at short wavelength.
文摘车用新鲜及废润滑油样品的傅里叶变换红外光谱(FT-IR)表明,两者中均存在羧基及羟基官能团,即存在酸性组分。利用具有超高分辨率的负离子电喷雾-傅里叶变换离子回旋共振质谱仪(negative-ion ESI FT-ICR MS)分析了车用新鲜及废润滑油中酸性化合物的组成及分布。结果表明,从新鲜润滑油中鉴定出的酸性化合物主要为O3、O1及O2类,而从废润滑油中鉴定出的酸性化合物则主要为O3、O2、O4及O1类。经对比分析可知,新鲜润滑油中的酸性化合物在废润滑油中均存在,其种类及所占比例基本未发生变化,但绝对含量不同;废润滑油中新产生的O3、O2及O1类酸性化合物种类较多,但其所占比例较小;车用新鲜与废润滑油中酸性组分的显著差异在于后者中产生了前者所没有的O4类化合物,且所占比例较大。
基金supported by the National Basic Research Program of China(2010CB226901)the National Natural Science Foundation of China(U1162204 and 21236009)
文摘This paper examined the bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds in Sudan heavy petroleum fraction. Both broadband and quadrupole isolation modes positive-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） coupled with collision induced dissociation （CID） tech- niques were used to characterize a low sulfur crude oil derived vacuum residuum （VR）. The appropriate CID operating condi- tion was selected by comparing the molecular weight distributions of the basic nitrogen compounds under various CID operat- ing conditions. Both odd- and even-electron fragment ions were observed from the mass spectrum, indicating that the hetero- lyric and homolytic bond cleavages occurred simultaneously during the CID process. The odd-electron fragment ions were predominant in each class species, indicating preferential heterolytic bond cleavages. At the optimal CID condition, the alkyl groups decomposed deeply and just left the aromatic cores of the nitrogen compounds. No Significant variation in double bond equivalent （DBE） value was observed between the fragment and parent ions, revealing that the domination of single core structure.
基金supported by the National Key Research and Development Program of China(No.2017YFE0133200)the National Natural Science Foundation of China(Nos.21876210 and 21806173)+1 种基金the Guangdong Provincial Science and Technology Planning Projects(No.2019A050503006)Hong Kong RGC(Nos.16206416 and T21-604/19-R)。
文摘UV/chlorine process,as an emerging advanced oxidation process(AOP),was effective for removing micro-pollutants via various reactive radicals,but it also led to the changes of natural organic matter(NOM)and formation of disinfection byproducts(DBPs).By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS),the transformation of Suwannee River NOM(SRNOM)and the formation of chlorinated DBPs(Cl-DBPs)in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark chlorination.In comparison to dark chlorination,the involvement of Cl O·,Cl·,and HO·in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity(AI mod)value and DBE(double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic compounds.Meanwhile,more compounds which contained only C,H,O,N atoms(CHON)were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions.A total of 833 compounds contained C,H,O,Cl atoms(CHOCl)were observed after the UV/chlorine AOP,higher than 789 CHOCl compounds in dark chlorination,and one-chlorine-containing components were the dominant species.The different products from chlorine substitution reactions(SR)and addition reactions(AR)suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher aromaticity.Post-chlorination further caused the cleavages of NOM structures into small molecular weight compounds,removed CHON compounds and enhanced the formation of Cl-DBPs.The results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.
