For research use only. Not for use in diagnostic procedures.
Analyst® 1.7 software has a scheduled ionization feature that can be used to set a selected range for sample ionization. The start and stop time for an acquisition method with the scheduled ionization feature selected should be developed based on the data that was acquired using the same acquisition method but without the scheduled ionization selected. The scheduled ionization feature can be used to reduce the mass spectrometer downtime by decreasing the risk of contamination. It is available in the acquisition method editor and can be used for batch acquisition using a single-period acquisition method.
To set up a method with scheduled ionization, select and set the start and stop times for scheduled ionization so that the ion spray voltage (ISV) in ESI mode is set to the ISV value specified in the acquisition method only during the start and the stop times where the peaks of interest elute. The ISV is set to 0 before the start time and after the stop time. The LC method should be set as usual.
For example, when the LC duration is set to 6 min, scheduled ionization is set to start at 1 min and stop at 4 min. Then the LC will start at 0 min and stop at 6 min. The mass spectrometer data collection will start at 1 min and then stop at 4 min. Scheduled ionization can also be used for the nebulizer current (NC) in APCI mode.
In the above method, source voltage was turned off for time window 1 and 3 (see image below). Data collection was activated for time window 2, when the ion source voltage was activated.