Rapid and sensitive analysis of trace β-blockers by magnetic solid-phase extraction coupled with Fourier transform ion cyclotron resonance mass spectrometry / 药物分析学报

A rapid and sensitive method for analyzing trace β-blockers in complex biological samples,which involved magnetic solid-phase extraction(MSPE)coupled with Fourier transform ion cyclotron reso-nance mass spectrometry(FTICR-MS),was developed.Novel nanosilver-functionalized magnetic nano-particles with an interlayer of poly(3,4-dihydroxyphenylalanine)(polyDOPA@Ag-MNPs)were synthesized and used as MSPE adsorbents to extract trace β-blockers from biological samples.After extraction,the analytes loaded on the polyDOPA@Ag-MNPs were desorbed using an organic solvent and analyzed by FTICR-MS.The method was rapid and sensitive,with a total detection procedure of less than 10 min as well as limits of detection and quantification in the ranges of 3.5-6.8 pg/mL and 11.7-22.8 pg/mL,respectively.The accuracy of the method was also desirable,with recoveries ranging from 80.9％to 91.0％following the detection of analytes in human blood samples.All the experimental results demonstrated that the developed MSPE-FTICR-MS method was suitable for the rapid and sensitive analysis of trace β-blockers in complex biological samples.

The Interaction between Aptamer and Beclomethasone Based on High Resolution Mass Spectrometry and Molecular Docking / 中国生物化学与分子生物学报

Beclomethasone is an effective glucocorticoid, and beclomethasone-aptamer is a short single-stranded DNA with affinity and specificity to beclomethasone. The interaction between them is still unclear. The study of the interaction between aptamers and beclomethasone has a certain significance for the application of aptamers. In this study, high-resolution Fourier transform ion cyclotron resonance mass spectrometer (FT-MS) and molecular docking simulation technology were used to study the interaction between aptamer and beclomethasone. Firstly, under the optimized conditions of high-resolution mass spectrometry parameters, the complex of aptamer and beclomethasone was detected by the negative ion scanning mode with the electrospray ion source. Based on the results of high-resolution mass spectrometry, most of the compounds were -8-valent ions, and their dissociation constant K

Rapid Characterization of Triacylglycerols in Edible Oils by Matrix-assisted Laser Desorption/Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry / 分析化学

Content and type of triacylglycerols(TAGs) in edible oils are closely related with our health,it is of significance to develop a fast and high-efficiency method for the determination of TAGs. In this manuscript, a fast and direct method for qualitative analysis of TAGs was established using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). 2,5-DHB was employed as matrix and dichloromethanewas used as solvent for dissolving edible oils. With laser power of 15%,laser frequency of 100 Hz and 100 laser shots, repeatability was evaluated using relative standard deviation (RSD) and less than 10% was obtained. Different kinds of edible oils could be directly distinguished from each other using MS and MS/MS results. With confidence level of 95%, principal component analysis(PCA) results show that 34 different kinds of edible oils were clearly classified. Using this method 5% doped canola in olive was identified directly,indicating that MALDI-FTICR-MS has the potential for rapid analyzing and screening edible oils.

Rapid Identification of Oligosaccharide Isomers by Electron Capture Dissociation in Combination with Metal Ions / 分析化学

Oligosaccharide isomers were distinguished by electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry ( ECD-FT-ICR-MS ) in combination with utiliZing alkali, alkaline earth, and transition metals ( Na+, Ca2+, Ba2+, Mg2+, Mn2+ and Co2+) as charge carriers in electrospray.Maltoheptaose, mannohexaose and laminarihexaose were taken as examples to investigate influence of metal ions on the extent of oligosaccharide fragmentation.The same types of fragmentation ions ( 0,2 A and 2,4 A) were obtained for barium- and calcium-adducted maltoheptaose.Mg2+ and Mn2+ had the similar influence ( 0,2 A, 2,4 A and 2,5 A ).Three cross-ring cleavage ions ( 1,4 A, 2,4 A and 2,5 A ) were generated in the spectrum of cobalt-associated maltoheptaose.But in the case of doping Na+into maltoheptaose, only 0,2 A ion was detected.It was found that the signals in the spectra of mannohexaose and laminarihexaose were worse than that in the spectrum of maltoheptaose, probably resulting from different numbers of adducted metal ions.The isomers, mannohexaose and laminarihexaose could be distinguished by ECD-MS in conjunction with the addition of Ca2+, Mg2+ or Co2+.The addition of Ca2+ was the best choice for analysis of oligosaccharides.

Absolute Quantification of Human Growth Hormone by Isotope Dilution-High Performance Liquid Chromatography-Mass Spectrometry / 分析化学

A method was developed for the quantification of human growth hormone ( hGH ) by protein purification and isotope dilution-high performance liquid chromatography mass spectrometry ( HPLC-IDMS ) . The hGH was purified and fractionated by fast protein liquid chromatography ( FPLC ) , then hGH molecular weight was accurately determined by Fourier transform ion cyclotron resonance mass spectrometer ( FTICR-MS). The purified hGH was hydrolyzed and the separation was performed on an KINETEX C18 column (150 mmí2 mm I. D. , 2. 6 μm) with water ( containing 0. 1% TFA) and acetonitrile isocratic solution as the mobile phase at a flow rate of 0 . 2 mL/min and 40℃. The electrospray source was operated in the positive ion mode, and monitored in the multiple reaction monitoring ( MRM) mode. The measured hGH molecular weight by FTICR-MS was only 0. 31 Da difference from theoretical value. Three amino ( proline, valine and phenylalanine) were clearly separated by isocratic elution within 5 min. Under the optimized conditions, the content of hGH was 186 . 80 μg/g with a RSD of 0 . 5%. The detection results of hGH in international comparison by this method were consistent with the reference value, which validated the feasibility of the established method. The developed method is simple, practical, accurate, reliable and reproducible, and can be used for the hGH quantitation of pure hGH CRM to provide reference for the routine detection of hGH.

Synthesis and Characterization of Methylsulfonium Salt in Diesel Fraction Using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry / 分析化学

Sulfur compounds in the diesel were selectively derived into methylsulfonium salts by reacting with iodomethane in the presence of silver tetrafluoroborate, and characterized by positive-ion electrospray ionization (ESI) fourier transform ion cyclotron resonance (FT-ICR MS). The conversion ratios and react selectivities of the methylation for various sulfur compounds were investigated by gas chromatograph coupled with pulse flame photometric detector (GC-PFPD). Result shows that the sulfur compounds in the diesel can react with iodomethane easily at room temperature, the most of sulfur compound derived into methylsulfonium salts;the homologue of benzothiophene get the higher conversion ratio and react selectivity than the homologue of dibenzothiophene (DBT). It is found that primarily sterically hindered alkylated DBT, for example, 4- or 4-, 6- DBT, is recalcitrant to be methylated. Other than benzothiophenes and dibenzothiophenes, one- and two-ring sulfides, as well as other sulfur compounds with a double bond equivalent (DBE) value ranged from 1 to 12 are identified in the diesel.