Abundance sensitivity is a measure of the tailing of an intense ion beam onto neighboring masses. This can be caused by the scattering of ions, for example by their interaction with residual gas molecules. The result are elevated baselines for masses neighboring bright ion beams.

The Retarding Potential Quadrupole (RPQ) acts as a high selectivity energy filter for ions with disturbed energy or angle. Both Thermo Scientific Neoma MC-ICP-MS and Thermo Scientific Triton XT TIMS can be configured with two RPQ lenses, producing abundance sensitivities of <0.5 ppm and < 20 ppb respectively (at 1 amu either side of ²³⁸U).