[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived f...[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.展开更多
In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin （TTX） in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/qua...In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin （TTX） in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry （LC-QqLIT-MS）. TTX was extracted by 1% acetic acid-methanol, and most of the lipids were then removed by freezing lipid precipitation, followed by purification and concentration using immunoaffinity columns （IACs）. Matrix effects were substantially reduced due to the high specificity of the IACs, and thus, background interference was avoided. Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase. The method was evaluated by fortifying samples at 1, 10, and 100 ng/g, respectively, and the recoveries ranged from 75.8%--107%, with a relative standard deviation of less than 15%. The TTX calibration curves were linear over the range of 1-1 000 ~tg/L, with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g. Using this method, samples can be further analyzed using an information- dependent acquisition （IDA） experiment, in the positive mode, from a single liquid chromatography-tandem mass spectrometry injection, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion （EPI） library. The scheduled multiple reaction monitoring method enabled TTX to be screened for, and TTX was positively identified using the IDA and EPI spectra. This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products. The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility, and is suitable for the analysis of complex matrix pufferfish samples.展开更多
In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC...In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC-MS/MS) analysis. Fol- lowing protein digestion with trypsin, the peptide mixture was analyzed by on-line RPLC-MS/MS. Bovine serum albumin (BSA) was used to optimize acetonitrile (ACN) elution gradient for tryptic peptides, and Cytochrome C was used to retest the gradient and the sensitivity of LC-MS/MS. The characteristics of identi?ed peptides were also analyzed. In our experiments, the suitable ACN gradient is 5% to 30% for tryptic peptide elution and the sensitivity of LC-MS/MS is 50 fmol. Analysis of the tryptic peptides demonstrated that longer (more than 10 amino acids) and multi-charge state (+2, +3) peptides are likely to be identi?ed, and the hydropathicity of the peptides might not be related to whether it is more likely to be identi?ed or not. The number of identi?ed peptides for a protein might be used to estimate its loading amount under the same sample background. Moreover, in this study the identi?ed peptides present three types of redundancy, namely iden- ti?cation, charge, and sequence redundancy, which may repress low abundance protein identi?cation.展开更多
The positive and negative ESI-MS/MS spectra of N-ethoxy（phenyl） phosphoryl amino acids（EPP-AA） were investigated by electrospray ionization（ESI） ion trap mass spectrometry. The fragmentation pathways of [ M ＋ N...The positive and negative ESI-MS/MS spectra of N-ethoxy（phenyl） phosphoryl amino acids（EPP-AA） were investigated by electrospray ionization（ESI） ion trap mass spectrometry. The fragmentation pathways of [ M ＋ Na]^＋ and [ M - H]^- ions are proposed and rationalized. The observation may have some potential applications in the interpretation of the MS/MS spectra of novel N-phosphoryl compounds. The complexity of MS/MS spectra of EPP-AA [ M ＋ Na]^＋ ions is decreased compared with that of N-dialkyloxyphosphoryl amino acid. Therefore, the new phosphonamidate method may be considered one of the superior methods that can be used in sequencing peptides and proteins extensively.展开更多
Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass...Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass spectrometry (ESI MS)in conjunction with tandem mass spectrometry.The fragmentation pathways of dialkyl puerarin-7-yl phosphates were investigated.展开更多
Rimonabant was studied by ESI ion trap mass spectrometry and EI(electron impact) time-of-flight mass spectrometry.m/z 380.9 can be used for identification of this drug by LC-MS.An exact mass at m/z 462.0782 (calculate...Rimonabant was studied by ESI ion trap mass spectrometry and EI(electron impact) time-of-flight mass spectrometry.m/z 380.9 can be used for identification of this drug by LC-MS.An exact mass at m/z 462.0782 (calculated 462.0781) with abundance (8.56%) in the spectra was found for its molecular ion.Ten characteristic fragment peaks with relatively strong intensities were observed,which can be used for identification of this drug.展开更多
基金Supported by Scientific Research Project of Dalian Customs(2022DK09).
文摘[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.
基金Supported by the National Natural Science Foundation of China(No.41106109)the China National Food Safety Standards Development Project(No.ZHENGHE-2015-356)
文摘In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin （TTX） in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry （LC-QqLIT-MS）. TTX was extracted by 1% acetic acid-methanol, and most of the lipids were then removed by freezing lipid precipitation, followed by purification and concentration using immunoaffinity columns （IACs）. Matrix effects were substantially reduced due to the high specificity of the IACs, and thus, background interference was avoided. Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase. The method was evaluated by fortifying samples at 1, 10, and 100 ng/g, respectively, and the recoveries ranged from 75.8%--107%, with a relative standard deviation of less than 15%. The TTX calibration curves were linear over the range of 1-1 000 ~tg/L, with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g. Using this method, samples can be further analyzed using an information- dependent acquisition （IDA） experiment, in the positive mode, from a single liquid chromatography-tandem mass spectrometry injection, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion （EPI） library. The scheduled multiple reaction monitoring method enabled TTX to be screened for, and TTX was positively identified using the IDA and EPI spectra. This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products. The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility, and is suitable for the analysis of complex matrix pufferfish samples.
基金This work was partially supported by grants fromthe National Basic Research Program (973) of China(2004CB520804), and National Natural Science Foun-dation of China (No. 30270657, 30230150, 3037030).
文摘In this study we systematically analyzed the elution condition of tryptic peptides and the characteristics of identi?ed peptides in reverse phase liquid chromatogra- phy and electrospray tandem mass spectrometry (RPLC-MS/MS) analysis. Fol- lowing protein digestion with trypsin, the peptide mixture was analyzed by on-line RPLC-MS/MS. Bovine serum albumin (BSA) was used to optimize acetonitrile (ACN) elution gradient for tryptic peptides, and Cytochrome C was used to retest the gradient and the sensitivity of LC-MS/MS. The characteristics of identi?ed peptides were also analyzed. In our experiments, the suitable ACN gradient is 5% to 30% for tryptic peptide elution and the sensitivity of LC-MS/MS is 50 fmol. Analysis of the tryptic peptides demonstrated that longer (more than 10 amino acids) and multi-charge state (+2, +3) peptides are likely to be identi?ed, and the hydropathicity of the peptides might not be related to whether it is more likely to be identi?ed or not. The number of identi?ed peptides for a protein might be used to estimate its loading amount under the same sample background. Moreover, in this study the identi?ed peptides present three types of redundancy, namely iden- ti?cation, charge, and sequence redundancy, which may repress low abundance protein identi?cation.
基金Supported by the Education Department of Henan Province(No. 200510459015).
文摘The positive and negative ESI-MS/MS spectra of N-ethoxy（phenyl） phosphoryl amino acids（EPP-AA） were investigated by electrospray ionization（ESI） ion trap mass spectrometry. The fragmentation pathways of [ M ＋ Na]^＋ and [ M - H]^- ions are proposed and rationalized. The observation may have some potential applications in the interpretation of the MS/MS spectra of novel N-phosphoryl compounds. The complexity of MS/MS spectra of EPP-AA [ M ＋ Na]^＋ ions is decreased compared with that of N-dialkyloxyphosphoryl amino acid. Therefore, the new phosphonamidate method may be considered one of the superior methods that can be used in sequencing peptides and proteins extensively.
文摘Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass spectrometry (ESI MS)in conjunction with tandem mass spectrometry.The fragmentation pathways of dialkyl puerarin-7-yl phosphates were investigated.
文摘Rimonabant was studied by ESI ion trap mass spectrometry and EI(electron impact) time-of-flight mass spectrometry.m/z 380.9 can be used for identification of this drug by LC-MS.An exact mass at m/z 462.0782 (calculated 462.0781) with abundance (8.56%) in the spectra was found for its molecular ion.Ten characteristic fragment peaks with relatively strong intensities were observed,which can be used for identification of this drug.
