Good morning.
I have two simple questions regarding the temperature parameter. If I make several methods consisting of different temperature and gas flow in a single randomised run, lets say alternating the temperature 750 –>150 –>450 –>150 –>750, will the instrument stabilise before each run for the temperature OR will it continue to before reaching the stabilisation? How about in SCIEX 6500?
I have another question regarding the Shimadzu Nexera LC hyphenated to our MS7500. How to set liquid sensing to the injection needle? I noticed that the instrument is capable of pick air in the empty vial without warning sign giving false negative result. I realise this when I was doing individual standard checking.
Please advise me. Thank you, Dhaya
Regarding your question on temperature control of the SCIEX sources. The control is consistent between all of our sources (Turbo V source, IonDrive Turbo V source and the OptiFlow sources). When the source temperature is changed during batch acquisition, the system will not go into a ready state (will stay in Equilibrating) until the Temperature readback from the source gets to within a certain tolerance. This is similar between Analyst software and SCIEX OS software.
The source TEM readback stabilizes very quickly when heating up because the sensor is in the heater itself. It’s slower to cool down because the heat needs to dissipate on its own.
But what really matters is the temperature that the ions actually experience for desolvation, and that lags behind the display of source TEM in the UI readback. In order for the temperature near the spray plume to equilibrate, a lot of the thermal mass in the source/interface needs to have reasonably stabilized. This is especially important for compounds that are particularly temperature sensitive. For that reason, it is good to avoid big, random jumps in temperature like you describe. The time to fully equilibrate the source at the new temperature will depend on the size and direction of the temperature step. Perhaps a good approach to test what will work for your particular experimental case is to do replicate injections for the planned temperature changes and monitor to see when the response is stable.
Here are some references that might be helpful for you.
1. For method transfer ideas, refer to MRM method transfer from a SCIEX Triple Quad or QTRAP 6500+ system to the SCIEX 7500 system. https://community.sciex.com/2021/10/29/mrm-method-transfer-from-a-sciex-triple-quad-or-qtrap-6500-system-to-the-sciex-7500-system/
2. For more info on general source tuning across the SCIEX suite of source options, refer to General source/gas settings to use when starting method development. https://community.sciex.com/2021/08/06/guidance-for-source-tuning-on-the-optiflow-pro-ion-source/h/2021/12/05/general-source-gas-settings-to-use-when-starting-method-development/
3. For information on tuning the source on the SCIEX 7500 system refer to Guidance for source tuning on the OptiFlow Pro ion source. https://community.sciex.com/2021/08/06/guidance-for-source-tuning-on-the-optiflow-pro-ion-source/
With regards to your Shimadzu question, I’m don’t think that liquid sensing is in our implementation of software control for that LC system.