Multiple tandem quadrupole mass

Hsu, F.F., Turk, J., Williams, T.D. and Welti, R. (2007) Electrospray ionization multiple stage quadrupole ion-trap and tandem quadrupole mass spectrometric studies on phos-phatidylglycerol from Arabidopsis leaves. J. Am. Soc. Mass Spectrom. 18, 783-790. 

Tandem quadrupole mass separators Up to 20000 for multiple pass quadrupoles... 

Multiple mass analyzers exist that can perform tandem mass spectrometry. Some use a tandem-in-space configuration, such as the triple quadrupole mass analyzers illustrated (Fig.3.9). Others use a tandem-in-time configuration and include instruments such as ion-traps (ITMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS or FTMS). A triple quadrupole mass spectrometer can only perform the tandem process once for an isolated precursor ion (e.g., MS/MS), but trapping or tandem-in-time instruments can perform repetitive tandem mass spectrometry (MS ), thus adding n 1 degrees of structural characterization and elucidation. When an ion-trap is combined with HPLC and photodiode array detection, the net result is a profiling tool that is a powerful tool for both metabolite profiling and metabolite identification. 

Triple Quadrupole MS/MS The final topic to consider is the use of multiple mass analyzers in drug analysis. The most important is the triple quadrupole instrument. It is a very good method of drug measurement. It can be both very selective and sensitive. The principal is illustrated in Figures 11.20A and 11.20B. The instrument uses three quadrupole mass analyzers in tandem. The first mass analyzer is used to select a... 

Tandem mass spectrometry (MS/MS), in its simplest and earliest implementations on quadrupole ion traps (QlTs), employed sequential (tandem-in-time MS/MS) isolation and energetic (for example, collisional) activation steps [16-22]. Modem MS/ MS experiments can involve multiple stages of mass selectivity (MS"), which employ different dissociation methods. Depending upon precursor chemistry, sometimes... 

It has been demonstrated also that the iTRAQ tandem mass spectrometric quantitative analysis strategy can be used in conjunction with the quadrupole ion trap by performing multiple stages of mass analysis (that is, MS ) [125], For example, chemical derivatization with the iTRAQ reagent not only labels the N-terminus of a peptide, but the lysine side chain also. Thus, tryptic peptides with a modified lysine residue present at the C-terminus will produce a yj product ion at m/z 291 following ClD-tandem mass spectrometry. To generate the low m/z iTRAQ reporter ions required for quantitation, the yj product ion is isolated and subjected to data-dependent CID-MS. Using this approach, peptide identification is achieved in the MS/MS scan, while quantitation is achieved via MS. ... 

Figure 2.2 Scan types utilized in lipidomic analysis by ESl-MS/MS. An MS/MS instrument consists of an initial mass (m/z) analyzer (MSi), a collision cell, and a second mass (m/z) analyzer (MSj). The two mass (m/z) analyzers and collision cell are separated in space on a beam instrument, such as tandem quadrupoles and Q-TOFs, and in time in ion traps. Product-ion, precursor-ion, and neutral-loss scans are performed by respectively scanning MSj, MSj, or MSj and MS2 in parallel. Multiple reaction monitoring (MRM) chromatograms are recorded with MSj and MSj fixed for transitions of interest. MS or MS/MS/MS spectra are recorded when a third mass (m/z) analyzer MS3 is utilized following a second collision cell. MS and further MS" spectra are often recorded on ion-trap instruments.

Hsu, F.-F., Turk, J. (2005) Studies on phosphatidylserine by tandem quadrupole and multiple stage quadrupole ion-trap mass spectrometry with electrospray ionization structural characterization and the fi agmen-tation processes./Aw Soc Mass Spectrom, 16, 1510-1522. 

Auld J, Hastie DR. Tandem mass spectrometry and multiple reaction monitoring using an atmospheric pressure chemical ionization triple quadrupole mass spectrometer for product identification in atmospherically important reactions. Int J Mass Spectrom. 2009 282 91-8. 

Hsu, RR, Turk, J., Rhoades, E.R., Russell, D.G., Shi, Y.X. and Groisman, E.A., Structural characterization of cardiohpin by tandem quadrupole and mulhple-stage quadrupole ion-trap mass spectrometry with electrospray ionization. J. Am. Soc. Mass Spectrom., 16, 491-504 (2005). Hsu, RR and Turk, J., Characterization of cardiohpin from Escherichia coli by electrospray ionization with multiple stage quadrupole ion-trap mass spectrometric analysis of [M — 2H -I Na](—) ions. J. Am. Soc, Mass Spectrom., 17, 420-429 (2006). 

A further extension of the DFG S19 method was achieved when polar analytes and those unsuitable for GC were determined by LC/MS or more preferably by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Triple-quadrupole MS/MS and ion trap MS" have become more affordable and acceptable in the recent past. These techniques provide multiple analyte methods by employing modes such as time segments, scan events or multiple injections. By improving the selectivity and sensitivity of detection after HPLC separation, the DFG S19 extraction and cleanup scheme can be applied to polar or high molecular weight analytes, and cleanup steps such as Si02 fractionation or even GPC become unnecessary. 

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