Pseudo MRM Mode on the “Brick” Mass Spectrometer Using the Grid-SWIFT Waveform

Besides portability and increasingly improved performances, the ability of screening target analyte from complex compounds is a crucial function of miniature mass spectrometers, especially for in-situ analysis. Selected reaction monitoring (SRM) and multiple reaction monitoring (MRM) operation modes are the most widely used mass spectrometry operation methods for target analyte quantitation. As a continuous effort to improve the analytical performances of the “brick”MS (mass spectrometer) built in house, pseudo SRM and MRM modes were realized on the linear ion trap mass analyzer in the device. A broadband excitation waveform in both time and frequency domains, namely the Grid-SWIFT waveform, was constructed and compared with the conventional SWIFT waveform. By isolating target ions during the ion introduction period using the Grid-SWIFT waveform, target ions could be efficiently accumulated inside the ion trap without experiencing space charge effects and interferences from non-target ions in the samples....