Comparison of negative ion electrospray mass spectra measured by seven tandem mass analyzers towards library formation

2007 ◽  
Vol 22 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Kateřina Volná ◽  
Michal Holčapek ◽  
Lenka Kolářová ◽  
Karel Lemr ◽  
Josef Čáslavský ◽  
...  

2018 ◽  
Author(s):  
Zhiwu An ◽  
Fuzhou Gong ◽  
Yan Fu

We have developed PTMiner, a first software tool for automated, confident filtering, localization and annotation of protein post-translational modifications identified by open (mass-tolerant) search of large tandem mass spectrometry datasets. The performance of the software was validated on carefully designed simulation data. <br>



Author(s):  
Serkan Levent ◽  
Saniye Özcan ◽  
Aysun Geven ◽  
Nafiz Öncü Can

Introduction:: In the present study, a sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was described for the determination of ceftiofur (CEF) in cow milk and pharmaceutical preparations. CEF is an antibiotic compound, which is commonly used in the treatment of animal diseases such as respiratory system, soft tissue, and foot infections, as well as postpartum acute puerperal metritis. One of the critical features of CEF is its prescription while breastfeeding of cows; in accordance, its quantitative estimation is essential to assess its residual amounts. Methods:: In the method reported herein, after simple protein precipitation using acetonitrile, the pre-treated samples were introduced in to an LC-MS/MS instrument equipped with a Chromolith® High-Resolution RP-18 series HPLC column (100 mm × 4.6 mm from Merck KGaA, Germany). Electrospray ionization was employed as the ionization source in the triplequadrupole tandem mass spectrometer. Results:: For the calibration method using solvent-based standards; LOQ was 3.038 ng/mL, 12.15 ng/mL, and LOD was 1.215 ng/mL and 6.076 ng/mL for ESI+ and ESI- modes, respectively. On the other hand, for the method of matrix-matched standards; LOQ was 1.701 ng/mL, 10.13 ng/mL, and LOD was 0.486 ng/mL and 5.929 ng/mL for ESI+ and ESI- modes, respectively as obtained from signal to noise ratio. Conclusion:: Applicability of both positive and negative ion modes was tested, and the analyte was detected via multiple reaction monitoring. The distorting effects of the milk matrix on the MS ionization and quantitation of CEF were overcome by using matrix-matched calibration for the first time.



Author(s):  
Xiaoyu Yang ◽  
Pedatsur Neta ◽  
Yuri A. Mirokhin ◽  
Dmitrii V. Tchekhovskoi ◽  
Concepcion A. Remoroza ◽  
...  


Author(s):  
Xiabing Li ◽  
Wuqun Tao ◽  
Hang Xun ◽  
Xi Yao ◽  
Jin Wang ◽  
...  

AbstractAn analytical method for the simultaneous determination of ten major functional flavonoids (isoorientin, orientin, vitexin, isovitexin, apigenin, luteolin, tricin, quercetin, rutin, and kaempferol) in different bamboo species was developed by liquid chromatography-tandem mass spectrometry. Chromatographic separation was carried out on a reversed-phase C-18 column with acetonitrile and water as the mobile phases. Detection was performed in negative ion electrospray ionization mode using multiple reaction monitoring mode. The correlation coefficients for the calibration curves ranged from 0.9955 to 0.9997. The limit of detection ranged from 1 to 45 ng/ml. The applicability of this analytical approach was confirmed by the successful analysis of real leaf samples of four bamboo species, family Poaceae: Pleioblastus amarus (Keng) Keng f., Phyllostachys glauca McClure, Phyllostachys edullis (Carrière) J.Houz, and Indocalamus latifolius (Keng) McClure. The total flavonoid contents were 3321.09, 3095.96, 4037.33, and 2808.42 mg/kg for P. amarus, P. glauca, P. edullis, and I. latifolius, respectively. Graphical abstract



1997 ◽  
Vol 13 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Kevin B. Thurbide ◽  
C. M. Elson ◽  
P. G. Sim

The negative‒ion chemical ionization mass spectra of a group of structural isomers of amphetamine have been studied using carbon dioxide as the reagent gas. Characteristic and reproducible differences are observed for each member of the set implying that this technique offers a means of distinguishing among groups of amphetamine isomers. Characteristic adducts to the molecular ion are observed in the form (M–[H]+[O]) and (M–[H]+[CO2]). Descriptions of some fragments are given based on the mass spectral behaviour of a set of analogue compounds and the results of oxygen-18 labelled carbon dioxide reagent gas experiments. Contents of the carbon dioxide plasma and their impact on various analytes is also discussed.



Sign in / Sign up

Export Citation Format

Share Document