Quadrupole mass, generally spectrometry

Tandem mass spectrometry (MS-MS) using quadrupole mass analyzers or ion-trap analyzers facilitate the conducting MS-MS experiments and increases the sensitivity of detection. Fragmentation patterns of anthocyanins generally show the loss of a glycoside or... 

FIGURE 11.1 A generalized flow scheme that indicates the fundamental elements of LC-MS-based bioanalysis. Abbreviations LLE = liquid-liquid extraction SPE = solid-phase extraction RAM = restricted-access media TEC = turbulent flow liquid chromatography API = atmospheric-pressure ionization APCI = atmospheric-pressure chemical ionization ESI = electrospray ionization SQMS = single-quadrupole mass spectrometry TQMS = triple-quadrupole mass spectrometry TOF = time-of-flight Q-TOF = quadrupole TOF. (Reprinted from Ackermann et al. [4], with permission from John Wiley Sons, Inc.)... 

Developments in two general areas have spurred this progress. Sector and quadrupole mass analyzers, the traditional methods of separation of ions in mass spectrometry, have recently been complemented by the development of powerful Foiuier transform (FT-MS) and time-of-flight (TOF-MS) instruments. The TOF analyzers are particularly well-suited for detecting higher molar-mass species present in polymers. 

Of several methods available for the separation of charged ions only two are in general use in organic mass spectrometry, namely magnetic field deflection and quadrupole mass filtering. 

Quadrupole or radio-frequency mass analyzers have only recently become available with the mass range and resolution 42) to be of general use in inorganic and organometallie mass spectrometry, although they have been popular as small mass spectrometers built into specific systems as reaction monitors. They do have the advantage of essentially linear... 

In general, the quadrupole instruments do not achieve the mass range and the high resolution of sector instruments. However, the mass range and resolution are adequate for unit-resolution mass spectrometry, and the rapid scan and sensitivity make them especially suitable for use with capillary gas chromatography (Fig. 2.46). 

In the absence of tandem mass spectrometry equipment, almost equally reliable estimations of the PA concentrations can be made using gas chromatography-mass spectrometry (GC-MS). A standard quadrupole instrument, such as the one used for organic acid analysis, will be sufficient. Depending on the derivative, a choice between positive and negative ionization will have to be made. In general, a more extensive prepurification of the biological samples, will have to be realized. 

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