Quadrupole Performance Criteria

There are two very important performance specifications of a mass analyzer that govern its ability to separate an analyte peak from a spectral interference. The first is the resolving power (R), which in traditional mass spectrometry is represented by 

Practical Guide to ICP-MS A Tutorial for Beginners, Second Edition 

FIGURE 7.4 Profiles of different masses are built up using a multichannel data acquisition 

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GC-MS of the fluid inclusion oils can be performed on benchtop quadrupole, triple quadrupole, or sector instruments. The main criterion is sensitivity because such low amounts of oil are recovered from fluid inclusions, sometime lower-sensitivity instruments such as benchtop quadrupole instruments do not give sufficient quality data to be reliably interpreted. Further subordinate criteria are mass resolution and resolving power it helps to separate certain compounds using better than unit mass resolution and/or tandem mass spectrometry... 

Example In the manufacture of aircraft engines and gas turbines superalloy is widely used due to its excellent performance, which to a great extent depends on the content of trace elements in the alloy. Critical control of the alloy s composition is therefore essential for the safe operation of such engines. The obvious method to avoid isobaric interferences is to select isotopes where no interferences exist. While H, Pb, and Bi meet this criterion, in case of Sn only the Sn ion is free of superimpositions, whereas Sn has serious interferences from Ars, Mo N2, and "Te". To determine the correct content of elements in superalloy on a quadrupole GD instrument also when no suitable isotope exists, both matching the sample matrix by use of external standards and multivariable linear regression have extensively been used (Fig. 15.10) [61]. 

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