Selected ion monitoring scan type - TSQ Quantis Plus MS - TSQ Fortis Plus MS - TSQ Series - TSQ Altis MS - TSQ Quantis MS - TSQ Altis Plus MS - TSQ Fortis MS - Selected ion monitoring scan type - TSQ Quantis Plus MS - TSQ Fortis Plus MS - TSQ Series - TSQ Altis MS - TSQ Altis MS - TSQ Quantis MS - TSQ Quantis MS - TSQ Altis Plus MS - TSQ Fortis MS

Selected ion monitoring (SIM) monitors a particular ion or set of ions. You can use SIM experiments to detect small quantities of a target compound in a complex mixture when you know the m/z of the target compound. Therefore, SIM is useful in trace analysis and in the rapid screening of a large number of samples for a target compound.

Because SIM monitors only a few ions, it can provide lower detection limits and greater speed than the full-scan modes. SIM achieves lower detection limits because more time is spent monitoring specific ions that are known to occur in the mass spectrum of the target analyte.

SIM can improve the detection limit and decrease analysis time, but it can also reduce specificity compared to SRM. Because SIM monitors only specific ions, any compound that is isobaric will appear to be the target compound, which can result in a false positive.