Which setup allows only ions of a single m/z value to pass while deflecting others?

The correct answer is a quadrupole. A quadrupole mass filter is designed to allow only ions of a specific mass-to-charge ratio (m/z) to pass through while deflecting ions of other m/z values. This works by using oscillating electric fields created by four rods arranged in a square configuration. The voltages applied to these rods create a specific instability for ions that do not have the desired m/z value, causing them to be deflected out of the path of the ion beam.

The quadrupole can be tuned to select ions of a particular m/z by adjusting the voltages applied to the rods, effectively filtering the incoming ions based on their mass. This precision makes it a critical component in various mass spectrometry applications for quantifying and analyzing compounds.

Other options may refer to separation techniques or devices but do not precisely describe the functioning mechanism of allowing only specific m/z ions to pass. A mass filter is a broader term that can refer to various devices, including quadrupoles, while “ionic separator” and “mass selector” are not standard terminologies within the context of mass spectrometry.