Xevo TQ MS MRM Sensitivity - WKB5404

SYMPTOMS

• After using sample tune and development, the MRM sensitivity is still low. 

ENVIRONMENT

• Xevo TQ MS
• MassLynx 4.1
• Xevo TQD

CAUSE

The source parameters still need to be optimized using the manual optimization feature in IntelliStart. 

FIX or WORKAROUND

1. Set the LC flow to the gradient composition and flow rate that the sample comes off in the gradient, for example, 50/50 A/B 0.4 mL/min.
2. Infuse the sample using the fluidics and select combined for the flow state. 
3. Open the MS console and go to the Xevo TQ MS and select the + twisty to the left of the name.
4. Select Manual Optimization.
5. Ensure that only the transition of interest is selected.
6. Right-click on the plot window and select plot properties.
7. Adjust the plot properties to one minute and wait for a minute to pass so that the plot is flat.
8. Adjust the capillary voltage to get the plot to give the maximum sensitivity. Note: for high flow rates, this will tune up at less than 1 kV.
9. Repeat for the desolvation temperature and probe position. There are three adjusters for the probe. Adjust all three to give the maximum sensitivity. 

ADDITIONAL INFORMATION