Reversed geometry instruments

Magnetic sectors can be used on their own, or in conjunction with energy analysers to fomi a tandem mass spectrometer. The unique features of the reverse geometry instrument are presented from this point. 

In a reversed geometry instrument, it is not possible to observe such metastable transitions in the conventional spectrum, since the ions produced in the first FFR cannot emerge from the electric field at the value . 

The MIKE and MIKE/CAD) method is used on a ZAB 2F reversed geometry instrument, designed by VG Micromass Instruments. 

Mass spectrometer configuration. Multianalyzer instruments should be named for the analyzers in the sequence in which they are traversed by the ion beam, where B is a magnetic analyzer, E is an electrostatic analyzer, Q is a quadrupole analyzer, TOP is a time-of-flight analyzer, and ICR is an ion cyclotron resonance analyzer. For example BE mass spectrometer (reversed-geometry double-focusing instrument), BQ mass spectrometer (hybrid sector and quadrupole instrument), EBQ (double-focusing instrument followed by a quadrupole). 

Figure 1.1. Schematic of a double-focusing reverse geometry magnetic-sector instrument.

When the first quadrupole of a triple quadrupole is replaced by a double-focusing mass spectrometer, the instrument is termed a hybrid (i.e. a hybrid of magnetic sector and quadrupole technologies). Figure 3.9 shows the MSi unit as a forward-geometry instrument although there is no reason why this could not be of reversed- or even tri-sector geometry. 

In cooperation with instrument designers, the group of Hass [167] showed the advantages of data acquisition techniques, especially to automate the adjustment of the main beam studied scanning of the different fields and detection of multiple metastable ions the acquisition of metastable spectra the various calculations of exact mass and energy liberated during the formation of metastable ions the different automatic processes of the reversed geometry mass spectrometer, such as ZAB 2F. 

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