Paul traps space charge effects

Figure 6.24 Schematic illustration of the difference with respect to accurate definition of a chromatographic peak between fixed acquisition times ( scan times ) as used by a linear quadrupole, and variable acquisition times dictated by automated gain control (AGC) applied in order to control space charge effects in a Paul ion trap. Since the rate of ion arrival is lower at the extremities of the peak, the acquisition times for the trap are longer than near the peak maximum, so that the start and end points for peak area integration are less well defined that in the case of fixed acquisition intervals (can be scan times or SIM/MRM channel dwell times).

---