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Objective To rapidly identify the chemical constituents in a traditional Chinese medicine Yine Abrus (Xiangsiteng) by high-performance liquid chromatography-time of flight mass spectrometry (HPLC-TOF/MS) analysis technique. Methods A formula database including 28 compounds of Xiangsiteng was developed by Agilent software “Formula-Database Generator”. The total ion chromatograms of the Xiangsiteng extracts were obtained by HPLC-TOF/MS, and the chemical components were identified by automatic matching method according to the exact mass-to-charge ratio of each chemical component. The separation was performed on a Agilent Zorbax Eclipse SB-C18 column (3.0 mm×100 mm, 3.5 μm). The mobile phase composing of acetonitrile and 0.1% formic acid aqueous solution was used for gradient eluting. The flowing rate was 0.4 mL/min; the temperature of column was 25 °C; the UV detection wavelength was 254 nm; and the sample selection was 10 μL. The electrospray ionization (ESI) source was applied for MS analysis under positive ion and negative ion modes, with the mass scan range being m/z 100-1 200. Results HPLC-TOF/MS identified a total of 15 chemical components from Xiangsiteng extracts, including 10 in positive ion mode and 11 in negative ion mode, and 6 both in both positive and negative ion modes. Conclusion A rapid and efficient method for identifying the chemical components of traditional Chinese medicine Xiangsiteng by HPLC-TOF/MS has been established, and the chemical components of Xiangsiteng has been clarified, which lays a foundation for the quality control and further pharmacological study of Xiangsiteng.
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Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an important analytical technique for biological macromolecules,such as proteins,peptides and nucleic acid, especially in the field of microbial identification. Based on previous study,a linear MALDI-TOF MS has been designed and assembled for biological applications. The instrument comprises a vacuum system,a vacuum fast sample introduction system, an optical system, a time-of-flight mass analyzer, an ion source, a data acquisition system and an electric control system. The ion source adopts two-stage source acceleration,delayed extraction and dynamic pulse focusing technology. The time-of-flight distance of field-free drift region is about 1 meter. The optical system adopts a solid laser with adjustable frequency of 1-2000 Hz and spots of 20-100 μm. The angle of incidence laser is controlled at 5 degrees. A series of experiments are carried out to further evaluate the instrument performances. It can not only analyze the samples more than 199 kDa, but also achieve isotope resolution at 1000-3000 Da and up to 900(FWHM) at 5000-17000 Da. The minimum detectable concentration of gramicidin is 10 amol/μL, absolute sensitivity can reach up to 2. 56 amol. Independent detection of saliva samples from different targets shows that the instrument has high reproducibility. We identified Escherichia Coli and Shigella spp,which are two common bacteria but difficult to be differentiated by mass spectrometry,showing its potential identification for clinical microorganism. In a summary,this instrument can play a role on clinical examination in the near future.
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Reduced sulfur compounds ( RSCs) are one of the main pollutant species in the atmosphere, so it is of great significance to develop a rapid and on-line approaches for their detection. In this study, a portable time-of-flight mass spectrometer ( TOF-MS) with magnetic field enhanced photoelectron ionization source was designed to detect RSCs. The photoelectron ionization source was induced from vacuum ultraviolet photons which generated from vacuum ultraviolet (VUV) lamp with energy of 10. 6 eV. The energy of photoelectrons was controlled by adjusting the extraction voltage to produce the photoelectron ionization, and an annular magnet was used in the ionization region to improve the ionization efficiency of photoelectrons. From the simulation result by SIMION software, it was found that the introduction of magnet field made the motion trajectroies of electrons in the helical motion increase and the convergence of electron at the ionization source was achieved. Experimental results showed that after introducing the magnet filed, the sensitivity of H2 S, SO2 and CS2 was improved by a factor of 5. 3, 9. 4 and 6. 9, respectively. With a detection time of 50 s, the limits of detection for H2S, SO2 and CS2 were 0. 14, 0. 52 and 0. 31 mg/m3(S/N=3), respectively. It could be concluded that the portable TOF-MS with magnetic field enhanced photoelectron ionization source has great potential to be applied for on-line monitoring of volatile sulfides at the emission source.
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Objective: To develop an LC/MS approach based on precise mass and tandem mass spectrometer to identify homoisoflavonoids from Ophiopogon japonicus alcohol extract. Methods: Separation was performed on an Alltima C18 reverse-phase column (250 mm x 4.6 mm, 5 μm) and an Alltech pre-column. The mobile phase consisted of water containing 1 mmol/L ammonium acetate-acetonitrile containing 0.01% acetic acid was used as gradient elution. The flow rate was 1.0 mL/min. The detection wavelength was 298 nm. A combination of time-of-flight mass spectrometer (TOF/MS) and ion trap tandem mass spectrometer (Trap/MSn) was applied for qualitative analysis under negative ion mode. Results: From the alcohol extract of O. japonicus, the molecular formulae of 11 components were screened by TOF/MS and 11 chemical components were identified by Trap/MSn. All of the peaks were attributed. Conclusion: This method can be used to identify medicinal ingredients quickly and provide an effective and reliable analytical model, as well as other complex system of traditional Chinese medicine compound.
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PURPOSE: Screening in cervical cancer is now progressing to discover candidate genes and proteins that may serve as biological markers and that play a role in tumor progression. We examined the protein expression patterns of the squamous cell carcinoma (SCC) tissues from Korean women with using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer. MATERIALS AND METHODS: Normal cervix and SCC tissues were solubilized and 2-DE was performed using pH 3~10 linear IPG strips of 17 cm length. The protein expression was evaluated using PDQuest 2-D software(TM). The differentially expressed protein spots were identified with a MALDI-TOF mass spectrometer, and the peptide mass spectra identifications were performed using the Mascot program and by searching the Swiss-prot or NCBInr databases. RESULTS: A total of 35 proteins were detected in SCC. 17 proteins were up-regulated and 18 proteins weredown-regulated. Among the proteins that were identified, 12 proteins (pigment epithelium derived factor, annexin A2 and A5, keratin 19 and 20, heat shock protein 27, smooth muscle protein 22 alpha, alpha-enolase, squamous cell carcinoma antigen 1 and 2, glutathione S-transferase and apolipoprotein a1) were protein previously known to be involved in tumor, and 21 proteins were newly identified in this study. CONCLUSION: 2-DE offers the total protein expression profiles of SCC tissues; further characterization of these differentially expressed proteins will give a chance to identify the badly needed tumor-specific diagnostic markers for SCC.
Subject(s)
Female , Humans , Annexin A2 , Apolipoproteins , Biomarkers , Carcinoma, Squamous Cell , Cervix Uteri , Databases, Protein , Electrophoresis, Polyacrylamide Gel , Epithelium , Glutathione Transferase , HSP27 Heat-Shock Proteins , Hydrogen-Ion Concentration , Keratin-19 , Mass Screening , Muscle, Smooth , Phosphopyruvate Hydratase , Uterine Cervical NeoplasmsABSTRACT
AIM: To develop a combinative LC/MS for the identification of multi-component in Danshen Dro-(pping) Pills(Radix et Rhizoma Salviae miltiorrhizale,Radix et Rhizoma Notoginseng,Borneolum Syntheticum,etc.). METHODS: Separation was performed on a Phenomenex Luna C_(18) reverse-phase column(250 mm?4.6 mm,5 ?m).The mobile phase consisted of water containing 0.2% formic acid and acetonitrile was used as gradient elute.The flow rate was 1 mL/min.A combination of time-of-flight mass spectrometer(TOF-MS) and ion trap tandem mass spectrometer(Trap-MS~n) was applied for qualitative analysis under negative ion mode. RESULTS: Under optimized LC/MS condition,the molecular formulae of 14 components were screened by TOF-MS and 13 of them were then identified by Trap-MS~n.All of the components were surveyed and classified according to their medicinal materials derivation. CONCLUSION: The established combinative LC/MS method can thus be considered as an effective and credible pattern for the analysis of Chinese multi-herb remedy,as well as other complex systems.