60 Agilent 6400 Series Triple Quad LC/MS Concepts Guide
3 Agilent Triple Quadrupole MS and Sensitivity
Collision cell
A potential difference is always present. This ensures that the
precursor ions coming from MS1 (Q1), or fragment ions
generated in the collision cell, are transmitted and not allowed
to drift around at random.
Sweeping out the ions in this manner avoids the issue of
crosstalk where residual product ions from a previous MRM
experiment can interfere with the product ion spectrum of
a subsequent MRM experiment (see Figure 29). A collision
energy voltage is applied over the accelerating linear voltage to
generate fragments or product ions.
Length of time for collision cell flushing
The low degree of crosstalk can be demonstrated by examining
how long it takes to evacuate ions from the collision cell
(Figure 29).
Figure 28 Collision cell design