Magnetic sector mass analyzer method

Due to the low spatial and energetic spread of ions from TI, the method can be combined with single-focusing magnetic sector mass analyzers or quadrupoles [35], Nonetheless, TI ion sources require dedicated instrumentation, frequently equipped with multicollector (MC) systems to insure the highest accuray for the isotope ratios measured (Chaps. 3.3.2 and 7.2 in [3]). 

Coal liquids are complicated mixtures. Separation of different compound types by liquid chromatography (LC) prior to MS analysis is a common practice. LC-MS, using both quadrupole and magnetic sector mass spectrometers, was applied to analyze aromatic fractions of coal tars, and the results were also compared with GC-MS and the above GC-MS combination methods. The molecular weight range observed by LC-MS was much greater than that observed by GC-MS and was similar to those observed by GC-MS combination methods. 

Before ehding this presentation on mass spectrometry, we should cite the existence of spectrometers for which the method of sorting ions coming from the source is different from the magnetic sector. These are mainly quadripolar analyzers and, to a lesser degree, analyzers measuring the ion s time of flight. 

MALDI generated a great demand for a mass analyzer ideally suited to be used in conjunction with a pulsed ion source and capable of transmitting ions of extremely high mass up to several 10 u. [24] Since then, the performance of TOF instruments has tremendously increased. [25,26] TOF analyzers were adapted for use with other ionization methods and are now even strong competitors to the well-established magnetic sector instruments in many applications. [25,27]... 

LC-MS methods, some of which have been optimized for FFF techniques or could potentially be good detection tools for FFF separations. The issue in the coupling of a liquid-based separation method to a mass spectrometer is the ion source conversion of dissolved analytes to ions in the high vacuum mass analyzer, which, for instance, can be magnetic sectors, quadrupoles, ion traps, or time-of-flight analyzers. Different ion sources give different information depending on the ionization mechanisms and will be discussed for each method. 

In the past decade, mass spectrometry (MS) has become the method of choice for quality control of synthetic peptides. Historically, plasma desorption (PD) and fast atom bombardment (FAB) were the first ionization methods used for the mass analysis of nonderivatized peptides. More recently, electrospray ionization (ESI) MS and matrix-assisted laser desorption ionization (MALDI) MS have found widespread utility for peptide analysis. Both of the latter methods yield protonated molecules and, thus, provide direct molecular weight information. As will be covered later, ESI can be employed with a variety of mass analyzers, including quadrupole, magnetic sector, ion trap, and time-of-flight (TOF) analyzers. On the other hand,... 

The ICP/MS is an elemental and isotopic analysis method that was first developed in the early 1980s. The ICP had been used only as a source for emission spectroscopy until it was adapted for producing ions for a mass analyzer (Douglas and French, 1981 Houk et al., 1980 Houk et al., 1981 Houk and Thompson, 1982). Since 1983, several manufacturers have sold ICP/MS instruments that incorporate various mass analyzer systems, such as quadrupole mass filter, magnetic sector field, time-of-flight, Paul ion trap, and ion detection systems such as the electron... 

The main advantage of the FAB technique compared to ESI and MALDI is, in fact, not the ionization method itself but the type of mass analyzer it works with. FAB ion sources are usually attached to magnetic sector, double-focusing mass spectrometers, enabling accurate mass measurements and, which is even more important, allowing the study of high-energy collision-induced dissociation (CID) reactions which provide information about the structure of the studied ion (see next section). 

Mass analysis is simply a method of separating ions of different mass-to-charge ratio [mlz). However, since the ions of interest are almost exclusively singly charged the mlz is equivalent to mass for most practical purposes. There are three types of mass analyzer used for ICP-MS, quadrupole, time-of-flight (TOF), and magnetic sector. 

---