A sensitive analytical method on cortisol in marine fish serum was established using ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).The cortisol in marine fish serum...A sensitive analytical method on cortisol in marine fish serum was established using ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).The cortisol in marine fish serum was extracted with chloroform,dried under nitrogen gas,and solved in 1:1 methanol-H2O for analysis,with dexamethasone as internal standard.The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization in negative mode,with m/z 407.2 for cortisol and 437.2 for dexamethasone,respectively.The results showed efficient separation of cortisol and dexamethasone are achieved on BEH C18 column.The linearity was good with the equation : Y=0.0154X+0.0451,from 0 to 200 ng/mL,with correlation coefficient of 0.999 3 and low detection limit of 1.64 pg.The average recovery was from 93.3% to 98.1%,with SD less than 10%.Using this method,corsitol in yellow croaker and Japanese sea bass collected in Ningbo China,were determined with content ranged from 0 to 15.81 ng/mL.展开更多
The mass spectrometric fragmentation of TMS derivatives of sterols was studied and analyzed based on the mass spectrometry of the TMS derivatives of standards.The double bond numbers and the degree of the methylize,al...The mass spectrometric fragmentation of TMS derivatives of sterols was studied and analyzed based on the mass spectrometry of the TMS derivatives of standards.The double bond numbers and the degree of the methylize,alkylize and the related position in the sterol nucleus and the side chains were confirmed by the characteristic ions.Total lipids were extracted using Bligh-Dyer method.Sterols were isolated by solvent partition with chloroform-hexane(1 ∶4,by volume),derivated by BSTFA,and analyzed by GC-MS.The regular pattern was used for identifying the sterols in a dinoflagellate from the Symbodinium sp.展开更多
The qualitative and quantitative research on glycolipids compounds was analyzed by means of the flight time ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-Q-TOF-MS) technology.The mass spec...The qualitative and quantitative research on glycolipids compounds was analyzed by means of the flight time ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-Q-TOF-MS) technology.The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization.The components in monoglycosyldiglycerides(MGDG) and diglycosyldiglycerides(DGDG) were determined in positive ion mode,and the sulfoquinovosyl diacylglycerol(SQDG) were analyzed in negative ion mode.The results showed that each component in golycolipids can be separated effectively with gradient elution in the BEH C18 column.The proportion of each components accounts for total glycolipids can be determined by using degree elution.展开更多
文摘A sensitive analytical method on cortisol in marine fish serum was established using ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).The cortisol in marine fish serum was extracted with chloroform,dried under nitrogen gas,and solved in 1:1 methanol-H2O for analysis,with dexamethasone as internal standard.The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization in negative mode,with m/z 407.2 for cortisol and 437.2 for dexamethasone,respectively.The results showed efficient separation of cortisol and dexamethasone are achieved on BEH C18 column.The linearity was good with the equation : Y=0.0154X+0.0451,from 0 to 200 ng/mL,with correlation coefficient of 0.999 3 and low detection limit of 1.64 pg.The average recovery was from 93.3% to 98.1%,with SD less than 10%.Using this method,corsitol in yellow croaker and Japanese sea bass collected in Ningbo China,were determined with content ranged from 0 to 15.81 ng/mL.
文摘The mass spectrometric fragmentation of TMS derivatives of sterols was studied and analyzed based on the mass spectrometry of the TMS derivatives of standards.The double bond numbers and the degree of the methylize,alkylize and the related position in the sterol nucleus and the side chains were confirmed by the characteristic ions.Total lipids were extracted using Bligh-Dyer method.Sterols were isolated by solvent partition with chloroform-hexane(1 ∶4,by volume),derivated by BSTFA,and analyzed by GC-MS.The regular pattern was used for identifying the sterols in a dinoflagellate from the Symbodinium sp.
文摘The qualitative and quantitative research on glycolipids compounds was analyzed by means of the flight time ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-Q-TOF-MS) technology.The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization.The components in monoglycosyldiglycerides(MGDG) and diglycosyldiglycerides(DGDG) were determined in positive ion mode,and the sulfoquinovosyl diacylglycerol(SQDG) were analyzed in negative ion mode.The results showed that each component in golycolipids can be separated effectively with gradient elution in the BEH C18 column.The proportion of each components accounts for total glycolipids can be determined by using degree elution.
