Fig. 2. Event sequence of experimental cycles. The vertical dashed lines
symbolize (from left to right) the start signal, the end signal and the
start signal of the next cycle.
Furthermore, by utilizing the RFQs
and FLT, the API-MRTOF-MS can operate in bunch mode, resulting in higher
duty cycle and enabling ion selection. In the typical continuous mode
shown in Fig. 2 (FLT caps signal), ions are only utilized during ion
filling time, and the duty cycle is determined by the ratio of filling
time to cycle time. While in the bunch mode shown in Fig. 3, ions can be
preserved by RFQ1, allowing for a 100% duty cycle. Moreover, by
adjusting the pulse time of the FLT end cap, the instrument can choose
ions based on their mass-to-charge ratio. Selectivity is vital for the
analysis of processes, which often presents unique demands on analytical
techniques, especially when dealing with complex samples. The
high-resolution and fast mass analysis provided by API-MRTOF-MS will
enable the analysis of transient processes. There are two ways that aid
in progress: releasing unwanted small ions and preventing unwanted large
ions from entering. Also, RFQ2 could act as a quadrupole for coarse ion
selection. This section also addresses the issue of mass bandwidth
improvement, which will be reported elsewhere in the near future.