Keeping a Nano LC/MS System Running after Sample Acquisition Is Completed

For research use only. Not for use in diagnostic procedures.

Answer

When using a nano LC/MS system, the LC flow may be left running even when the mass spectrometer finishes acquisition and goes to standby mode. The LC flow rate for nano systems is typically 300 nl/min. (With a micro 200 LC, where the flow rate is 45 µl/min, it is not recommended that LC flow continues after acquisition completes. The reservoir for each pump stroke is only 600 µl, and this would quickly deplete the reservoir.)

To configure a nano LC for continuous flow, either from the Eksigent software or the Analyst® software, use the following settings:

1) Select the nano LC from the Eksigent software under Instrument Configuration, and then click on Advanced Tab and select Turn pumps off when in system Standby mode. Then in the Analyst software, navigate to Configure mode by selecting Tools-Settings-Queue Options. In the queue option window, please set the Max. Idle time to a very long time (e.g., 999 min) for nano flow configurations. (For micro flow, set this for a very short amount of time.)

2) Create a method with a very low flow rate and run it at the end of the batch. In this case, leave the Max. Idle time large (e.g., 999 min) to keep the LC flow going when using a nano LC.