Quadrupole mass analyzer

Ions are separated in a quadrupole based on the stability of their trajectories in the oscillating electric fields that are applied to the rods.

This permits selection of an ion with a particular m/z or allows the operator to scan for a range of m/z-values by continuously varying the applied voltage.

Different manufacturers choose slightly different ratios to fine-tune operating characteristics in context of anticipated application requirements.

The arrangement of three quadrupoles was first developed by Jim Morrison of La Trobe University in Australia for the purpose of studying the photodissociation of gas-phase ions.

[5] The first triple-quadrupole mass spectrometer was developed at Michigan State University by Christie Enke and graduate student Richard Yost in the late 1970s.

An enhancement to the performance of the quadrupole mass analyzer has been demonstrated to occur when a magnetic field is applied to the instrument.

Manifold improvements in resolution and sensitivity have been reported for a magnetic field applied in various orientations to a QMS.