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Ion-trap Tandem Mass Spectrometry (ion-trap + tandem_mass_spectrometry)

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Chemistry100%

Selected Abstracts

High-performance liquid chromatography with diode array detection coupled to electrospray time-of-flight and ion-trap tandem mass spectrometry to identify phenolic compounds from a Cistus ladanifer aqueous extract

PHYTOCHEMICAL ANALYSIS, Issue 4 2010
S. Fernández-Arroyo
Abstract Introduction , Cistus ladanifer is an aromatic shrub that is widespread in the Mediterranean region. The labdanum exudate is used in the fragrance industry and has been characterised. However, there is not enough information about the phenolic content of the raw plant, the aerial part of it being a very rich source of bioactive compounds. Objective , Characterisation of the bioactive compounds of the raw plant and its aerial parts. Methodology , High-performance liquid chromatography with diode array and electrospray ionisation mass spectrometric detection was used to carry out the comprehensive characterisation of a Cistus ladanifer shrub aqueous extract. Two different MS techniques were coupled to HPLC: time-of-flight mass spectrometry and tandem mass spectrometry. Results , Many well-known compounds present in Cistus ladanifer were characterised, such as flavonoids, phenolic acids, ellagitanins, hexahydroxydiphenoyl and derivatives, and other compounds. Conclusion , The method described simultaneously separated a wide range of phenolic compounds and the proposed characterisation of the major compounds of this extract was carried out. It is important to highlight that, to our knowledge, this is the first time that a Cistus ladanifer aqueous extract from the raw plant has been characterised. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Identification and structural characterization of steroidal glycosides in Hoodia gordonii by ion-trap tandem mass spectrometry and liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2008
Bharathi Avula
Electrospray ion-trap tandem mass spectrometry (ESI-MS/MS) and high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOFMS) were used to identify and characterize eight C-21 steroidal glycosides in Hoodia gordonii. A generalized fragmentation pathway was proposed by comparing the spectra acquired for eight C-21 steroidal glycosides. The steroidal glycosides in Hoodia gordonii have been classified into two major core groups: hoodigenin A and calogenin. Using the ESI-TOF method, the major core peak ions generated by hoodigenin A glycosides are m/z 313 and 295 and by calogenin glycosides are m/z 479, 461, 299 and 281, respectively. In the MS/MS spectra, fragmentation reactions of the [M+Na]+ ion were recorded to provide structural information about the glycosyl and aglycone moieties. The data illustrates the ability of positive mode ESI for the identification of hoodigenin A and calogenin glycosides, including the nature of the hoodigenin A and calogenin core, the number of sugar residues and the type of saccharide moiety. Copyright © 2008 John Wiley & Sons, Ltd. [source]

High-precision isotopic analysis of palmitoylcarnitine by liquid chromatography/electrospray ionization ion-trap tandem mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 22 2006
ZengKui Guo
Single quadrupole gas chromatography/mass spectrometry (GC/MS) has been widely used for isotopic analysis in metabolic investigations using stable isotopes as tracers. However, its inherent shortcomings prohibit it from broader use, including low isotopic precision and the need for chemical derivatization of the analyte. In order to improve isotopic detection power, liquid chromatography/electrospray ionization ion-trap tandem mass spectrometry (LC/ESI-itMS2) has been evaluated for its isotopic precision and chemical sensitivity for the analysis of [13C]palmitoylcarnitine. Over the enrichment range of 0.4,10 MPE (molar % excess), the isotopic response of LC/ESI-itMS2 to [13C]palmitoylcarnitine was linear (r,=,1.00) and the average isotopic precision (standard deviation, SD) was 0.11 MPE with an average coefficient of variation (CV) of 5.6%. At the lower end of isotopic enrichments (0.4,0.9 MPE), the isotopic precision was 0.05 MPE (CV,=,8%). Routine analysis of rat skeletal muscle [13C4]palmitoylcarnitine demonstrated an isotopic precision of 0.03 MPE for gastrocnemius (n,=,16) and of 0.02 MPE for tibialis anterior (n,=,16). The high precision enabled the detection of a small (0.08 MPE) but significant (P,=,0.01) difference in [13C4]palmitoylcarnitine enrichments between the two muscles, 0.51 MPE (CV,=,5.8%) and 0.43 MPE (CV,=,4.6%), respectively. Therefore, the system demonstrated an isotopic lower detection limit (LDL) of ,0.1 MPE (2 × SD) that has been impossible previously with other organic mass spectrometry instruments. LC/ESI-itMS2 systems have the potential to advance metabolic investigations using stable isotopes to a new level by significantly increasing the isotopic solving power. Copyright © 2006 John Wiley & Sons, Ltd. [source]