Why Is There No MRMHR Scan Type when Using the Method Wizard for a TripleTOF® LC-MS/MS System?｜質量分析計・LC-MS/MSシステムのSCIEX

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Answer

The MRM^HR workflow is used on a TripleTOF® LC-MS/MS System instrument to collect both optimized transitions as well as full-scan product ion spectra; these spectra can then be incorporated into compound libraries and used for compound identification or confirmation. MRM^HR is not a scan type. It is a description for a set of looped experiments, which can be used for a targeted approach. The looped experiments include a TOF-MS experiment followed by dedicated product ion experiments either in high-resolution or high-sensitivity mode.

The precursor ion scan and its various daughter ions or fragment ions can be used to create an extracted ion chromatogram (XIC) or MRM-like peak, which can be used for quantitation. Additionally, the acquired MS1 data is used automatically to keep the instrument properly tuned and calibrated during data acquisition. Even if the MS1 data is not used in the analysis, it is very important to ensure that it is included in the method.

MRM^HR is an alternative to MRM methods, whereby all product ions are acquired at high resolution for selected precursor ions isolated by the Q1 quadrupole. Specific transitions are then extracted post-acquisition with very narrow extraction windows thus allowing for extremely high specificity with near comparable sensitivity to QqQ instrumentation, as shown in the picture below.