基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量...基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量白酒中氨基甲酸乙酯(ethyl carbamate,EC)的方法。实验对HS-SPME方法进行了优化,在酒精度12%vol、加NaCl 3 g、萃取温度70℃,萃取时间40 min的条件下,能够显著提高目标物的响应值。实验以D_(5)-氨基甲酸乙酯(D_(5)-EC)为内标,对不同浓度的样品溶液进行GC×GC-TOFMS定量分析。结果表明,EC在10~500μg/L范围内线性关系良好,回归系数(R^(2))>0.998,检出限为0.19μg/L,定量限为0.64μg/L,平均回收率为97.57%,精密度为8.66%。测定结果与国标方法相比无显著性差异(P>0.05)。该方法前处理简单,检测灵敏度更高,为白酒中EC自动化定量测定提供了新思路。展开更多
In this study, biomarkers, together with stable carbon(δ13 C) and hydrogen(δD) isotopic compositions of n-alkanes have been examined in a suite of condensates collected from the East China Sea Shelf Basin(ECSSB) in ...In this study, biomarkers, together with stable carbon(δ13 C) and hydrogen(δD) isotopic compositions of n-alkanes have been examined in a suite of condensates collected from the East China Sea Shelf Basin(ECSSB) in order to delineate their source organic matter input, depositional conditions and evaluate their thermal maturity. Previously, GC-MS analyses have shown that all the condensates are formed in oxidizing environment with terrestrial plants as their main source input. No significant differences were apparent for biomarker parameters, likely due to the low biomarker content and high maturity of these condensates. Conventional GC-MS analysis however, may provides limited information on the sources and thermal maturity of complex mixtures due to insufficient component resolution. In the current study, we used comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry(GC×GC-TOFMS) to increase the chromatographic resolution. Compounds such as alkyl cyclohexanes, alkyl cyclopentanes and diamondoids, which can be difficult to identify using conventional GC-MS analysis, were successfully identified using GC×GC-TOFMS. From our analyses we propose two possibly unreported indicators, including one maturity indicator(C5--cyclohexane/C5+-cyclohexane) and one oxidation-reduction environment indicator(alkyl-cyclohexane/alkyl-cyclopentane). Multiple petroleum charging events were proposed as an explanation for the maturity indicators indexes discrepancy between methyl-phenanthrene index(MPI) and methyl-adamantane index(MDI). In addition, the stable isotopic results show that condensates from the Paleogene have significantly higher positive δ13 C values of individual n-alkanes than the Neogene samples. Based on δD values, the samples can be divided into two groups, the differences between which are likely to be attributed to different biosynthetic precursors. Variation within each group can likely be attributed to vaporization.展开更多
Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） ...Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.展开更多
Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and noris...Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and norisoprenoids in pine board might be introduced into Qingke Baijiu.Thus,the terpenoids and norisoprenoids in Qingke Baijiu were investigated by headspace solid phase microextraction(HS-SPME)combined with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry(GC×GC-TOFMS).The results showed thatγ-terpinene(0.70-530.72μg/L),α-phellandrene(0.34-256.66μg/L),longicyclene(0-38.55μg/L),α-pinene(1.21-35.54μg/L)and limonene(0.93-23.69μg/L)were the top 5 terpenoids/norisoprenoids in Qingke Baijiu.Pulegone was detected and reported for the first time in Baijiu,and the concentrations in Qingke Baijiu were 0.78μg/L(fresh)and 3.90μg/L(7 years old).According to the principal component analysis(PCA)plot,young,aged,and retail Qingke Baijiu could be differentiated clearly.Fold change(FC)and t-tests analysis indicated thatβ-pinene,γ-terpinene,andα-selinene were the most different terpenoids/norisoprenoids between young and aged Qingke Baijiu,and longifolene was the most different terpenoids/norisoprenoids between base and retail Qingke Baijiu.The terpenoids and norisoprenoids,such as(E)-β-ionone,isoborneol andβ-cyclocitral,could be potential markers indicating the ageing process of Qingke Baijiu.展开更多
The reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms f...The reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms for the genesis of co-existed complex petroleum phases and their distribution remains relatively limited.The quantitative assessment of changes in molecular compounds in petroleum pools influenced by secondary alteration to different degrees also needs further investigation.In this study,eight samples including condensate,volatile,and black oil from the Tazhong area were analyzed via GC×GC-TOFMS.The results reveal that condensate oil exhibits complete normal alkane distribution,with abundant diamantanes and organic sulfur compounds(OSCs),and features high density(>0.83 g/cm^(3)),elevated wax content(>20%),and remarkable gas washing loss.The condensate gas is characterized by highly mature oil-cracking gas with a heavy carbon isotope.Geological analysis indicates that the current Ordovician reservoir temperatures generally remain below 140℃,which is insufficient to induce in-situ oil cracking.Additionally,black oil pools are formed adjacent to the condensate gas pools,suggesting that the latter is not a result of in-situ oil cracking,but rather represents a secondary condensate gas pool formed through gas invasion of a pre-existed oil pool.Based on the loss of n-alkanes and variations in adamantanes(As)and diamantanes(Ds)content across different oil samples,the degree of gas invasion was assessed.We divided gas invasion intensity into strong(Q≥80%,As≥5000μg/g,Ds≥400μg/g),weak(20%≤Q<80%,3000μg/g≤As<5000μg/g,200μg/g≤Ds<400μg/g)and negligible(0≤Q<20%,As<3000μg/g,Ds<200μg/g).The multistage oil/gas charging events,specifically the sequence of“early oil and late gas”in the Ordovician from the Tazhong area,predominantly drives the phase evolution of reservoired petroleum.Furthermore,differential gas invasion alteration exacerbates the intricacy of petroleum phase distribution.Notably,gas washing processes significantly influence the disparate enrichment of diamondoids homologues in crude oil.Specifically,lower carbon number diamondoids are more abundant in condensate oil,while higher ones exhibit relatively increased abundance in black oil,potentially serving as a valuable quantitative assessment parameter.The findings in this study will provide guiding significance for the analysis and quantitative assessment of deep petroleum phase diversity.Additionally,this research will provide novel insights for comprehensively evaluating basins worldwide with complex petroleum phases distribution.展开更多
As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Bei...As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.展开更多
A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dim...A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude oils.Based on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient sediments.Oil samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter input.It should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.展开更多
Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO...Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.展开更多
文摘基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量白酒中氨基甲酸乙酯(ethyl carbamate,EC)的方法。实验对HS-SPME方法进行了优化,在酒精度12%vol、加NaCl 3 g、萃取温度70℃,萃取时间40 min的条件下,能够显著提高目标物的响应值。实验以D_(5)-氨基甲酸乙酯(D_(5)-EC)为内标,对不同浓度的样品溶液进行GC×GC-TOFMS定量分析。结果表明,EC在10~500μg/L范围内线性关系良好,回归系数(R^(2))>0.998,检出限为0.19μg/L,定量限为0.64μg/L,平均回收率为97.57%,精密度为8.66%。测定结果与国标方法相比无显著性差异(P>0.05)。该方法前处理简单,检测灵敏度更高,为白酒中EC自动化定量测定提供了新思路。
基金sponsored by the National Science and Technology Major Project of China (Nos. 2016ZX05024-002003, 2016ZX05027-001-005)
文摘In this study, biomarkers, together with stable carbon(δ13 C) and hydrogen(δD) isotopic compositions of n-alkanes have been examined in a suite of condensates collected from the East China Sea Shelf Basin(ECSSB) in order to delineate their source organic matter input, depositional conditions and evaluate their thermal maturity. Previously, GC-MS analyses have shown that all the condensates are formed in oxidizing environment with terrestrial plants as their main source input. No significant differences were apparent for biomarker parameters, likely due to the low biomarker content and high maturity of these condensates. Conventional GC-MS analysis however, may provides limited information on the sources and thermal maturity of complex mixtures due to insufficient component resolution. In the current study, we used comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry(GC×GC-TOFMS) to increase the chromatographic resolution. Compounds such as alkyl cyclohexanes, alkyl cyclopentanes and diamondoids, which can be difficult to identify using conventional GC-MS analysis, were successfully identified using GC×GC-TOFMS. From our analyses we propose two possibly unreported indicators, including one maturity indicator(C5--cyclohexane/C5+-cyclohexane) and one oxidation-reduction environment indicator(alkyl-cyclohexane/alkyl-cyclopentane). Multiple petroleum charging events were proposed as an explanation for the maturity indicators indexes discrepancy between methyl-phenanthrene index(MPI) and methyl-adamantane index(MDI). In addition, the stable isotopic results show that condensates from the Paleogene have significantly higher positive δ13 C values of individual n-alkanes than the Neogene samples. Based on δD values, the samples can be divided into two groups, the differences between which are likely to be attributed to different biosynthetic precursors. Variation within each group can likely be attributed to vaporization.
基金funded by the National Natural Science Foundation of China(Grant No.41172126)the State Key Laboratory of Petroleum Resources and Prospecting(PRP/indep-2-1402)
文摘Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.
基金financially supported by the National Key R&D Program of China(2016YFD0400500)
文摘Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and norisoprenoids in pine board might be introduced into Qingke Baijiu.Thus,the terpenoids and norisoprenoids in Qingke Baijiu were investigated by headspace solid phase microextraction(HS-SPME)combined with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry(GC×GC-TOFMS).The results showed thatγ-terpinene(0.70-530.72μg/L),α-phellandrene(0.34-256.66μg/L),longicyclene(0-38.55μg/L),α-pinene(1.21-35.54μg/L)and limonene(0.93-23.69μg/L)were the top 5 terpenoids/norisoprenoids in Qingke Baijiu.Pulegone was detected and reported for the first time in Baijiu,and the concentrations in Qingke Baijiu were 0.78μg/L(fresh)and 3.90μg/L(7 years old).According to the principal component analysis(PCA)plot,young,aged,and retail Qingke Baijiu could be differentiated clearly.Fold change(FC)and t-tests analysis indicated thatβ-pinene,γ-terpinene,andα-selinene were the most different terpenoids/norisoprenoids between young and aged Qingke Baijiu,and longifolene was the most different terpenoids/norisoprenoids between base and retail Qingke Baijiu.The terpenoids and norisoprenoids,such as(E)-β-ionone,isoborneol andβ-cyclocitral,could be potential markers indicating the ageing process of Qingke Baijiu.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.42002178 and 42472203)“CUG Scholar”Scientific Research Funds at China University of Geosciences(Grant No.2022193)China National Petroleum Corporation(CNPC)Scientific Research and Technology Development Projects(Grant Nos.2019B-04 and 2021DJ05)。
文摘The reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms for the genesis of co-existed complex petroleum phases and their distribution remains relatively limited.The quantitative assessment of changes in molecular compounds in petroleum pools influenced by secondary alteration to different degrees also needs further investigation.In this study,eight samples including condensate,volatile,and black oil from the Tazhong area were analyzed via GC×GC-TOFMS.The results reveal that condensate oil exhibits complete normal alkane distribution,with abundant diamantanes and organic sulfur compounds(OSCs),and features high density(>0.83 g/cm^(3)),elevated wax content(>20%),and remarkable gas washing loss.The condensate gas is characterized by highly mature oil-cracking gas with a heavy carbon isotope.Geological analysis indicates that the current Ordovician reservoir temperatures generally remain below 140℃,which is insufficient to induce in-situ oil cracking.Additionally,black oil pools are formed adjacent to the condensate gas pools,suggesting that the latter is not a result of in-situ oil cracking,but rather represents a secondary condensate gas pool formed through gas invasion of a pre-existed oil pool.Based on the loss of n-alkanes and variations in adamantanes(As)and diamantanes(Ds)content across different oil samples,the degree of gas invasion was assessed.We divided gas invasion intensity into strong(Q≥80%,As≥5000μg/g,Ds≥400μg/g),weak(20%≤Q<80%,3000μg/g≤As<5000μg/g,200μg/g≤Ds<400μg/g)and negligible(0≤Q<20%,As<3000μg/g,Ds<200μg/g).The multistage oil/gas charging events,specifically the sequence of“early oil and late gas”in the Ordovician from the Tazhong area,predominantly drives the phase evolution of reservoired petroleum.Furthermore,differential gas invasion alteration exacerbates the intricacy of petroleum phase distribution.Notably,gas washing processes significantly influence the disparate enrichment of diamondoids homologues in crude oil.Specifically,lower carbon number diamondoids are more abundant in condensate oil,while higher ones exhibit relatively increased abundance in black oil,potentially serving as a valuable quantitative assessment parameter.The findings in this study will provide guiding significance for the analysis and quantitative assessment of deep petroleum phase diversity.Additionally,this research will provide novel insights for comprehensively evaluating basins worldwide with complex petroleum phases distribution.
基金supported by Doctor's Scientific Research Initiation Project of Yan'an University(YAU202213093)National Nature Science Foundation of China(Grant No.41503029).
文摘As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.
基金supported by Doctor’s Scientific Research Initiation Project of Yan’an University(YAU202213093)National Natural Science Foundation of China(Grant No.41503029)。
文摘A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude oils.Based on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient sediments.Oil samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter input.It should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.
基金supported by the Natural Science Foundation of Zhejiang Province (No. LY21E060007)the National Natural Science Foundation of China (No. 52006191)。
文摘Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.
