How to tune up the resolution on a QTof - WKB13440

OBJECTIVE or GOAL

Increase the mass spectral resolution on a QTof.

ENVIRONMENT

• MassLynx 4.1
• SYNAPT G2 Si
• SYNAPT G2 S
• SYNAPT G2
• Xevo G2 XS
• Xevo GS S
• Xevo G2
• Xevo QTof

PROCEDURE

1. On the Tune page, from the setup drop-down menu, select System View. Password: "access".
2. Select Acquisition Settings. On the bottom left, you will see Resolution. This is the expected resolution for this mode. Take note of the resolution and exit this window.
3. Zoom in on lockmass peak.
4. Adjust counts to mid to low e4 counts by dropping the LockSpray capillary voltage. Or going to the System 2 tab under pDRE Test, select Attenuate, and adjust the Transmission until you have low e4 counts. Note: If you are comfortable doing so, right-click the peak in the tune page and select Intensity > select Normalize Data. This  allows you to see if the intensity is going up or down as you tune the resolution.
5. Zoom in on the peak so that you can easily see the peak shape.
6. Go to the System 2 page and adjust the reflectron grid by using the left or right arrow key (click on the slider to the right of the number in black, and then use the arrow keys on the keyboard). Tune for best resolution, peak shape, and sensitivity, with resolution being the highest priority.
7. Now go to the System 1 page and adjust the pusher offset by using the left or right arrow key (click on the slider to the right of the number in black, and then use the arrow keys on the keyboard). Tune for best resolution, peak shapem and sensitivity, with symmetrical peak shape being the highest priority.

ADDITIONAL INFORMATION