- After using sample tune and development, the MRM sensitivity is still low.
- Xevo TQ MS
- MassLynx 4.1
- Xevo TQD
The source parameters still need to be optimized using the manual optimization feature in IntelliStart.
FIX or WORKAROUND
- 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.
- Infuse the sample using the fluidics and select combined for the flow state.
- Open the MS console and go to the Xevo TQ MS and select the + twisty to the left of the name.
- Select Manual Optimization.
- Ensure that only the transition of interest is selected.
- Right-click on the plot window and select plot properties.
- Adjust the plot properties to one minute and wait for a minute to pass so that the plot is flat.
- 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.
- Repeat for the desolvation temperature and probe position. There are three adjusters for the probe. Adjust all three to give the maximum sensitivity.