Mass analyzers working principles

Before we go on to discuss these in greater detail and how these parameters affect the data, it is important to remind ourselves how a scanning device like a quadrupole mass analyzer works. Although we wiU focus on quadrupole technology, the fundamental principles of measurement protocol wiU be very similar for all types of mass spectrometers that use a sequential approach for multielement peak quantitation. 

This book is tailored to be your guide to mass spectrometry - from the first steps to your daily work in research. Starting from the very principles of gas phase ion chemistry and isotopic properties, it leads through design of mass analyzers, mass... 

Different mass analyzers may impose unique technical requirements when interfaced to LC. Understanding the operating principles and technical properties of both LC/MS interfaces and mass analyzers is deemed beneficial. A brief overview of the history of the development of LC/MS interfaces is given in Section II, which is followed in Section III by a summary of working principles and characteristics of commonly used mass analyzers. 

A brief description of the working principles of commonly used mass analyzers is given below. For a more comprehensive discnssion of the principles of these mass analyzers, excellent reviews can be fonnd in the literature. ... 

Mass analyzers use physical principles to separate the generated ions coming from the ionization source. Many physical principles have been tested for that purpose but only a few of them have become successful and are still enhanced to achieve better results in mass spectrometric analysis. The most common mass analyzers are listed in Table 5.2. Although in principle any source can be connected with any analyzer, some combinations are more common. For example, MALDI as a discontinuously working ion source can easily be coupled with time-of-flight analyzers, while ESI sources are often combined with quadrupoles and ion traps. Therefore, we restrict the discussion here to those analyzers which are typically available together with MALDI and ESI ion sources. 

Other Mass Analyzers. Other analyzers, such as quadrupole ion trap (QIP) and Fourier transform mass spectrometer (FTMS), are of some interest for proteomics. The quadrupole ion trap mass analyzer was devised by Wolfgang Paul it works on the principle of trapping ions with a particular RF in the quadrupole mass analyzer. This device provides a way to eject ions of certain radio frequency and retain the others, only the latter are allowed to reach the detector by scanning ions of a particular radio frequency. In this method, the selected ions can be subjected to fragmentation by collision-induced dissociation (CID), which is useful for the analysis of peptides. 

In this chapter the principles of various mass analyzers were enumerated. The function of a mass analyzer is to disperse all ions (in space, time, or frequency) in terms of their miq ratio. This work is accomplished by manipulating their momentum, kinetic energy, and velocity. Magnetic-sector instruments are one... 

Other ion traps such as the quadrupole ion trap and linear quadrupole ion trap have garnered a lot interest (33). The quadrupole ion trap works on the same physical principles as the quadrupole mass analyzer, but ions are trapped and sequentially ejected. A linear quadrupole ion trap is similar to a quadrupole ion trap, but it traps ions in a two-dimensional quadrupole field, instead of a three-dimensional quadrupole field as in a quadrupole ion trap. 

One disadvantage of the method when it comes to working with biological systems is sample size. Since natural abundance 180 is low (0.205 0.014%), samples must consist of at least 2 imol of gas. While this is often trivial for measurements upon inorganic compounds, this is not so for stoichiometric measurements on proteins when only submicromolar quantities are available. In principle, the O2 can be analyzed directly instead of the C02 however, C02 is easier to manipulate and mitigates wear on the isotope ratio mass spectrometer (IRMS). 

Process Technology 3—Operations—combines process systems into operational processes with emphasis on operations under various conditions. Topics include typical duties of an operator. Instruction focuses on the principles of modem manufacturing technology and process equipment. Emphasizes scale-up from laboratory bench to pilot unit. Describe unit operation concepts solve elementary chemical mass/energy balance problems interpret analytical data and apply distillation and fluid flow principles. The purpose of this class is to provide adult learners with the opportunity to work in a self-directed work team, operate a complex operational system, collect and analyze data, start and stop process equipment, follow and write operational procedures. The course is advanced and requires the learner to apply classroom skills to real-life operational activities. Students are required to qualify and operate a process unit. 

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