Identification and assay of carbohydrates in olive drupes by cesium attachment electrospray tandem mass spectrometry (ESI-MS/MS)

2012 ◽  
Vol 47 (9) ◽  
pp. 1242-1246
Author(s):  
A. Russo ◽  
M. Migliorini ◽  
L. Cecchi ◽  
C. Cherubini ◽  
M. Giusti ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms

Determination of lapatinib (GW572016) in human plasma by liquid chromatography electrospray tandem mass spectrometry (LC–ESI-MS/MS)

2006 ◽  
Vol 831 (1-2) ◽  
pp. 169-175 ◽  
Author(s):  
Feng Bai ◽  
Burgess B. Freeman ◽  
Charles H. Fraga ◽  
Maryam Fouladi ◽  
Clinton F. Stewart
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Human Plasma ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms

Electrospray Tandem Mass Spectrometry of β-Nitroalkenyl Meso-Tetraphenylporphyrins

2008 ◽  
Vol 14 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Eduarda M.P. Silva ◽  
Pedro Domingues ◽  
João P.C. Tomé ◽  
M. Amparo F. Faustino ◽  
M. Graça P.M.S. Neves ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Nitro Group ◽  
Relative Abundance ◽  
Bromine Atom ◽  
Tandem Mass ◽  
Fragmentation Pattern ◽  
Free Base ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms

β-Nitroalkenyl meso-tetraphenylporphyrins [β-TPPCHC(NO2)R)], as free-bases and Zn(II) complexes, were studied by electrospray mass spectrometry (ESI-MS). Under this ionisation condition the [M + H]+ ions are formed. The fragmentation pattern of the resulting [M + H]+ ions were studied by electrospray tandem mass spectrometry (ESI-MS/MS). The ESI-MS/MS of β-nitroalkenylporphyrins, either as free-bases or as Zn(II) complexes, show several interesting features, distinct from the typical behaviour of nitro compounds. For the studied compounds, common main fragmentation patterns are observed, namely characteristic losses of NO2•, HNO2, 2OH•, RNO2, RCNO, RCNO2, RCH2NO2, C6H5• plus NO2• and the formation of the protonated macrocycle, [TPP + H]+ or [ZnTPP + H]+. However, depending on the presence or absence of the metal and the nature of the R substituent, important differences are observed on the relative abundances of the ions formed by the same fragmentation pathway. The presence of bromine in the alkenyl group leads to a peculiar behaviour, since the main fragmentation pattern corresponds to the combined elimination of the bromine atom with the typical nitro group fragments. When R = Br, the loss of the nitro group occurs in low relative abundance (11-16%). However, when R = CH3, the relative abundance of the ion due to the loss of HNO2 changes drastically from 100%, observed for the free-base porphyrin, to 29% in the case of the Zn(II) complex. These variations of the relative abundance of the fragment corresponding to the loss of the nitro moiety (typically considered as a diagnostic fragment) can induce to an erroneous interpretation of their MS/MS spectra. Some fragmentations are observed only for the free-base porphyrins, namely the loss of •CH(NO2)R and HNO2 plus C2H2, while the loss of OH•, H2O, OH• plus H2O and RCCH plus H2O is observed only for the complexes. Unusual and unexpected fragmentations are also observed, namely the losses of RCNO, RCNO2 and HNO2 plus C2H2. This work demonstrates that valuable structural information about the β-nitroalkenyl substituents linked to meso-tetraarylporphyrins can be achieved using MS/MS. These results can also be useful for the interpretation of the mass spectra of other nitroalkenyl substituted compounds.

scholarly journals Simultaneous determination of cyclophosphamide and carboxyethylphosphoramide mustard in human plasma using online extraction and electrospray tandem mass spectrometry (HTLC–ESI-MS/MS)

2009 ◽  
Vol 877 (18-19) ◽  
pp. 1709-1715 ◽  
Author(s):  
Feng Bai ◽  
Charles H. Fraga ◽  
Michael Tagen ◽  
Paula Schaiquevich ◽  
Nikolaus Hagedorn ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Simultaneous Determination ◽  
Human Plasma ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms ◽  
Online Extraction

scholarly journals Determination of the γ-secretase inhibitor MK-0752 in human plasma by online extraction and electrospray tandem mass spectrometry (HTLC–ESI-MS/MS)

2010 ◽  
Vol 878 (25) ◽  
pp. 2348-2352 ◽  
Author(s):  
Feng Bai ◽  
Michael Tagen ◽  
Courtney Colotta ◽  
Laura Miller ◽  
Maryam Fouladi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Human Plasma ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms ◽  
Secretase Inhibitor ◽  
Online Extraction

scholarly journals Measurement of Plasma Renin Activity with Use of HPLC-Electrospray-Tandem Mass Spectrometry

1999 ◽  
Vol 45 (5) ◽  
pp. 659-664 ◽  
Author(s):  
Victoria F Fredline ◽  
Eva M Kovacs ◽  
Paul J Taylor ◽  
Anthony G Johnson
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Plasma Renin Activity ◽  
Limit Of Detection ◽  
Plasma Renin ◽  
Renin Activity ◽  
Selected Reaction Monitoring ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms

Abstract Background: The measurement of renin activity is complicated by difficulties in the quantification of angiotensin 1 (Ang1), the product of the renin-catalyzed reaction. We report an HPLC-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS) method for the quantification of Ang1 as a measure of plasma renin activity (PRA). Methods: After incubation (37 °C for 3 or 18 h), samples were prepared using C18 solid-phase extraction. [Val]5Ang1 was used as the internal standard (IS). Chromatography was performed on a C18 column, using 200 mL/L ammonium acetate buffer–800 mL/L methanol as the mobile phase. The flow rate was 150 μL/min, with a chromatographic run time of 5 min/sample. Mass spectrometric detection was in the positive ionization mode with selected reaction monitoring (Ang1 m/z 649.0→784.0; IS m/z 641.9→770.4). Results: The assay was linear over the range 2.5–500 ng Ang1/mL, which corresponded to a limit of detection (signal-to-noise ratio of 3:1) of PRA of 0.14 ng Ang1 · mL−1 · h−1. The imprecision (CV) of the assay at PRA values of 26.1, 13.5, 3.2, and 0.78 ng Ang1 · mL−1 · h−1 was 7.0%, 7.0%, 15%, and 11%, respectively. Absolute recoveries were 92.3% (Ang1) and 87.4% (IS). Incubation times of 3 h vs 18 h in the PRA assay gave good agreement at PRA <2 ng Ang1 · mL−1 · h−1, but samples with a PRA of 2–5 ng Ang1 · mL−1 · h−1 gave lower PRA results after incubation for 18 h than after 3 h. We compared the HPLC-ESI-MS/MS assay and an RIA for the determination of PRA, with PRA incubation times of 3 h and 1.5 h, respectively. The mean PRA based on RIA of Ang1 was higher than that obtained using HPLC-ESI-MS/MS. Conclusion: The HPLC-ESI-MS/MS method allows sensitive and specific measurement of PRA. The higher activities measured with the RIA method highlight its potential for overestimation of PRA.

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