可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方...可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方法,采用降噪、插值与归一化预处理质谱数据,相关系数法筛选样品重复测试中的异常值,主成分分析法评价插值后数据的质量,以验证压缩数据是否具有可行性。结果表明,正离子模式下香料A和香料B的未稀释样品分别被划分到甲醇体积分数0%~2%与0%~3%范围内,实际生产中可将此范围内的样品认定为质量合格。负离子模式样品响应低,优先考虑正离子模式评价可食用香料。展开更多
Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN...Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN sample by trypsin,the correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK were obtained by FT-ICR-MS.It showed that the method of nano-spray HPLC combined with FT-ICR-MS and Mascot search was very efficient for the analysis of the purified OPN and its polypeptide fragments.Further study provides more academic theories of their different modifications and the relative bioactivities.展开更多
FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most freque...FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.展开更多
The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to ana...The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to analyze a phosphorothioate oligonucleotide with 6 321 u.Experimental results showed that accurate relative molecular mass of phosphorothioate oligonucleotide determined by FT-ICR-MS can be used for confirmation of its composition.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
Dissolved organic matter(DOM)in refinery wastewater is an extremely complex mixture of various organic compounds.Using mass spectrometry,it is impossible to characterize all of the DOM molecules with only one ionizati...Dissolved organic matter(DOM)in refinery wastewater is an extremely complex mixture of various organic compounds.Using mass spectrometry,it is impossible to characterize all of the DOM molecules with only one ionization source.In this study,negative-ion,electrospray ionization(ESI),positive-ion ESI,and positive-ion atmospheric pressure photoionization(APPI)were coupled with Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)to analyze the molecular composition of DOM in a refinery wastewater stream during the treatment process.There were obvious differences in the heteroatom composition,number of DOM constituents,and chemical properties in refinery wastewater under the three ionization modes.Acidic CHO and CHOS compounds detected by(+)ESI,basic CHN and CHON compounds detected by(þ)ESI,and hydrocarbons detected by(+)APPI were analyzed to determine the molecular transformations that occurred during treatment.In an anaerobic biological treatment process,acidic CHO and CHOS compounds with a high oxygen content were preferentially removed,and acidic CHO and CHOS compounds with a low oxygen content were produced.In an aerobic biological process,acidic CHO and CHOS compounds with a low oxygen content were preferentially removed,and acidic CHO and CHOS compounds with a high oxygen content were produced.The whole biological treatment process has a poor removal efficiency for CHN and CHON compounds,and hydrocarbons.An activated carbon(AC)adsorption process removed different heteroatom compounds mainly with a low oxygen content for acidic and basic compounds.The transformation mechanism of CHO and CHOS compounds in the biological treatment process was analyzed by the Kendrick mass defect(KMD)theory and a mass difference network analysis.In the anaerobic process,large amounts of oxygenated CHO and CHOS compounds were degraded by decarboxylation,deoxydation,demethoxylation,and dehydration reactions,and converted to lower oxygen content compounds.In the aerobic processes,these low oxygen CHO and CHOS compounds mainly underwent carboxylation and oxidation reactions.This study determined the transformation characteristics and mechanisms of different types of organic compounds in refinery wastewater during the treatment process.The results provide guidance for the design and optimization of technologies for refinery wastewater treatment.展开更多
文摘可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方法,采用降噪、插值与归一化预处理质谱数据,相关系数法筛选样品重复测试中的异常值,主成分分析法评价插值后数据的质量,以验证压缩数据是否具有可行性。结果表明,正离子模式下香料A和香料B的未稀释样品分别被划分到甲醇体积分数0%~2%与0%~3%范围内,实际生产中可将此范围内的样品认定为质量合格。负离子模式样品响应低,优先考虑正离子模式评价可食用香料。
文摘Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN sample by trypsin,the correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK were obtained by FT-ICR-MS.It showed that the method of nano-spray HPLC combined with FT-ICR-MS and Mascot search was very efficient for the analysis of the purified OPN and its polypeptide fragments.Further study provides more academic theories of their different modifications and the relative bioactivities.
文摘FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.
文摘The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to analyze a phosphorothioate oligonucleotide with 6 321 u.Experimental results showed that accurate relative molecular mass of phosphorothioate oligonucleotide determined by FT-ICR-MS can be used for confirmation of its composition.
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This work was supported by the National Key Research and Development Program of China(2018YFA0605800 and 2020YFA0607600)the National Natural Science Foundation of China(42003059)Science Foundation of China University of Petroleum,Beijing(No.2462021XKBH005).
文摘Dissolved organic matter(DOM)in refinery wastewater is an extremely complex mixture of various organic compounds.Using mass spectrometry,it is impossible to characterize all of the DOM molecules with only one ionization source.In this study,negative-ion,electrospray ionization(ESI),positive-ion ESI,and positive-ion atmospheric pressure photoionization(APPI)were coupled with Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)to analyze the molecular composition of DOM in a refinery wastewater stream during the treatment process.There were obvious differences in the heteroatom composition,number of DOM constituents,and chemical properties in refinery wastewater under the three ionization modes.Acidic CHO and CHOS compounds detected by(+)ESI,basic CHN and CHON compounds detected by(þ)ESI,and hydrocarbons detected by(+)APPI were analyzed to determine the molecular transformations that occurred during treatment.In an anaerobic biological treatment process,acidic CHO and CHOS compounds with a high oxygen content were preferentially removed,and acidic CHO and CHOS compounds with a low oxygen content were produced.In an aerobic biological process,acidic CHO and CHOS compounds with a low oxygen content were preferentially removed,and acidic CHO and CHOS compounds with a high oxygen content were produced.The whole biological treatment process has a poor removal efficiency for CHN and CHON compounds,and hydrocarbons.An activated carbon(AC)adsorption process removed different heteroatom compounds mainly with a low oxygen content for acidic and basic compounds.The transformation mechanism of CHO and CHOS compounds in the biological treatment process was analyzed by the Kendrick mass defect(KMD)theory and a mass difference network analysis.In the anaerobic process,large amounts of oxygenated CHO and CHOS compounds were degraded by decarboxylation,deoxydation,demethoxylation,and dehydration reactions,and converted to lower oxygen content compounds.In the aerobic processes,these low oxygen CHO and CHOS compounds mainly underwent carboxylation and oxidation reactions.This study determined the transformation characteristics and mechanisms of different types of organic compounds in refinery wastewater during the treatment process.The results provide guidance for the design and optimization of technologies for refinery wastewater treatment.
