The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociatio...The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociation(CID) is a powerful method to characterize the molecular structure of petroleum fractions. In this work, model compounds with different aromatic ring structures were measured by CID FT-ICR MS. The cracking of the parent ions and the generated fragment ions were able to distinguish different linkage of the model compounds. Then, vacuum residues were separated into saturates, aromatics, resins and asphaltenes fractions(SARA), and each fraction was characterized by CID technology. According to the experimental results, the aromatic rings in saturates and aromatics fractions were mainly of the island-type structures, while the aromatic rings in resins and asphaltenes fractions had a significant amount of archipelago-type structures.展开更多
High resolution tandem mass spectrometry has been applied to obtain the structure information of petroleumsamples. Here, we report a mefflod for structural characterization of crude oil molecules by the collision-indu...High resolution tandem mass spectrometry has been applied to obtain the structure information of petroleumsamples. Here, we report a mefflod for structural characterization of crude oil molecules by the collision-induced dissocia-tion （CID） technology coupled wiffl the high-field Fourier transform ion cyclotron resonmlce mass spectrometry （FT-ICRMS）. The ion isolation window was narrowed down to 1 Da to distinguish file complex homologues contained in petroleum.Aromatic model compounds and crude oil samples were measured by CID FT-ICR MS at different collision energy levels.The fragmentation of model compounds wiffl alkyl side-chains was found to be related to the size of file aromatic rings. Thefragmentation of model compounds wiffl archipelago structures depended on file lengffl of file bridge alkylene chain. Theprevalent reaction pafflway of model compounds with naphthenic rings was mainly determined by the position of naphfflen-ic rings in file molecules. On file basis of file fragmentation pathways, the structure differences of two crude oils were recog-nized as different content of naphthenic rings by CID technology with 1 Da isolation window. The NMR analysis was alsoapplied to confirm file CID results. This study exhibits the great potential of CID FT-ICR MS wiffl narrow isolation windowin file smlctural characterization of crude oil molecules.展开更多
Liquid chromatography hybrid ion trap/time-of-flight mass spectrometry possesses both the MS^n ability of ion trap and the excellent resolution of a time-of-flight and has been widely used to identify drug metabolites...Liquid chromatography hybrid ion trap/time-of-flight mass spectrometry possesses both the MS^n ability of ion trap and the excellent resolution of a time-of-flight and has been widely used to identify drug metabolites and determine trace multi-components in natural products. Collision energy, one of the most important factors in acquiring MS^n information, could be set freely in the range of 10%–400%. Herein, notoginsenosides were chosen as model compounds to build a novel methodology for the collision energy optimization. Firstly, the fragmental patterns of the representatives for the authentic standards of protopanaxadiol-type and protopanaxatriol-type notoginsenosides were obtained based on accurate MS^2 and MS^3 measurements via liquid chromatography hybrid ion trap/time-of-flight mass spectrometry. The extracted ion chromatograms of characteristic product ions of notoginsenosides in Panax Notoginseng Extract were produced under a series of collision energies and compared to screen the optimum collision energies values for MS^2 and MS^3. The results demonstrated that the qualitative capability of liquid chromatography hybrid ion trap/time-of-flight mass spectrometry was greatly influenced by collision energies, and 50% of MS^2 collision energy was found to produce the highest collision-induced dissociation efficiency for notoginsenosides. Addtionally, the highest collision-induced dissociation efficiency appeared when the collision energy was set at 75% in the MS^3 stage.展开更多
The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built i...The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.展开更多
The dissociation routes of the adduct ions [M+CH3CO]+ formed by ion-moleculereaction of isomeric phenylenediamines with acetyl ion from acetone under chemical ionizationcondition were investigated by using collision-i...The dissociation routes of the adduct ions [M+CH3CO]+ formed by ion-moleculereaction of isomeric phenylenediamines with acetyl ion from acetone under chemical ionizationcondition were investigated by using collision-induced dissociation (CID) technique performed ation kinetic energies of 40eV. The adduct ions are intermediate ion-neutral complexes.展开更多
基金supported by the Major State Basic Research Development Program of China (973 Program, No. 2012CB224801)
文摘The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociation(CID) is a powerful method to characterize the molecular structure of petroleum fractions. In this work, model compounds with different aromatic ring structures were measured by CID FT-ICR MS. The cracking of the parent ions and the generated fragment ions were able to distinguish different linkage of the model compounds. Then, vacuum residues were separated into saturates, aromatics, resins and asphaltenes fractions(SARA), and each fraction was characterized by CID technology. According to the experimental results, the aromatic rings in saturates and aromatics fractions were mainly of the island-type structures, while the aromatic rings in resins and asphaltenes fractions had a significant amount of archipelago-type structures.
基金supported by the Key Laboratory of SINOPEC (KL17010)the research project of Research Institute of Petroleum Processing(R16075)
文摘High resolution tandem mass spectrometry has been applied to obtain the structure information of petroleumsamples. Here, we report a mefflod for structural characterization of crude oil molecules by the collision-induced dissocia-tion （CID） technology coupled wiffl the high-field Fourier transform ion cyclotron resonmlce mass spectrometry （FT-ICRMS）. The ion isolation window was narrowed down to 1 Da to distinguish file complex homologues contained in petroleum.Aromatic model compounds and crude oil samples were measured by CID FT-ICR MS at different collision energy levels.The fragmentation of model compounds wiffl alkyl side-chains was found to be related to the size of file aromatic rings. Thefragmentation of model compounds wiffl archipelago structures depended on file lengffl of file bridge alkylene chain. Theprevalent reaction pafflway of model compounds with naphthenic rings was mainly determined by the position of naphfflen-ic rings in file molecules. On file basis of file fragmentation pathways, the structure differences of two crude oils were recog-nized as different content of naphthenic rings by CID technology with 1 Da isolation window. The NMR analysis was alsoapplied to confirm file CID results. This study exhibits the great potential of CID FT-ICR MS wiffl narrow isolation windowin file smlctural characterization of crude oil molecules.
基金supported by the National Nature Science Foundation of China(Nos.81273589,81374054)the Nature Science Foundation of Jiangsu Province(BK20131311)+2 种基金the fundamental research special fund of China Pharmaceutical University(PT2014 YK0081)Jiangsu Provincial Promotion Foundation for the Key Laboratory of Drug Metabolism and Pharmacokinetics(BM2012012)Jiangsu Key Laboratory of Drug Design and Optimization
文摘Liquid chromatography hybrid ion trap/time-of-flight mass spectrometry possesses both the MS^n ability of ion trap and the excellent resolution of a time-of-flight and has been widely used to identify drug metabolites and determine trace multi-components in natural products. Collision energy, one of the most important factors in acquiring MS^n information, could be set freely in the range of 10%–400%. Herein, notoginsenosides were chosen as model compounds to build a novel methodology for the collision energy optimization. Firstly, the fragmental patterns of the representatives for the authentic standards of protopanaxadiol-type and protopanaxatriol-type notoginsenosides were obtained based on accurate MS^2 and MS^3 measurements via liquid chromatography hybrid ion trap/time-of-flight mass spectrometry. The extracted ion chromatograms of characteristic product ions of notoginsenosides in Panax Notoginseng Extract were produced under a series of collision energies and compared to screen the optimum collision energies values for MS^2 and MS^3. The results demonstrated that the qualitative capability of liquid chromatography hybrid ion trap/time-of-flight mass spectrometry was greatly influenced by collision energies, and 50% of MS^2 collision energy was found to produce the highest collision-induced dissociation efficiency for notoginsenosides. Addtionally, the highest collision-induced dissociation efficiency appeared when the collision energy was set at 75% in the MS^3 stage.
基金financially supported by the National Key R&D Program of China(2018YFF0212503,2019YFF0216303,and 2016YFF0200502)the National Natural Science Foundation of China(21927812)the Research Project of the National Institute of Metrology(AKY1934)。
文摘The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.
文摘The dissociation routes of the adduct ions [M+CH3CO]+ formed by ion-moleculereaction of isomeric phenylenediamines with acetyl ion from acetone under chemical ionizationcondition were investigated by using collision-induced dissociation (CID) technique performed ation kinetic energies of 40eV. The adduct ions are intermediate ion-neutral complexes.
