Multiplexed Post Source Decay (PSD MX): A novel technique explained
Post source decay (PSD) MALDI-TOF analysis is an established technique capable of providing complementary structural information. A conventional PSD experiment requires each precursor ion of interest to be isolated using a selecting device (such as an ion gate for example) so that all fragment ions may be associated with their correct precursor. We present a novel axial geometry MALDI-TOF mass spectrometer, which enhances PSD analysis by the simultaneous acquisition of PSD fragments from a mixture of precursors. This new, patented technique of parallel or multiplexed PSD (PSD MX) removes the need for an ion gate and is available on the Waters® MALDI micro MX™ Mass Spectrometer. The benefits of PSD MX are a significant reduction in both analysis time and sample consumption in comparison with conventional PSD. Additionally, with PSD MX there are no typical side effects from using an ion gate, such as loss of transmission (and hence sensitivity) and resolution.