Xevo family QTof: unstable lockspray signal - WKB278436

SYMPTOMS

• LockSpray dropouts or LockSpray signal missing intermittently
• Unstable or no spray from reference probe
• After every re-fill of the Reference syringe from reservoir B, it takes10–15 minutes for a stable LockSpray beam to appear.

ENVIRONMENT

• Xevo G2-XS QTof/Tof
• Xevo G2-S QTof/Tof
• Xevo G2 QTof/Tof
• Xevo G3 QTof
• MassLynx
• waters_connect UNIFI
• UNIFI

CAUSE

Air likely within the MS fluidics path

FIX or WORKAROUND

1. Replace the wash solution content with 100% IPA and disconnect tubing from reference selector valve port 4.

                      Diagram will be slightly different for Xevo G3 mass spec products - Refer to the Fluidics tech ref document.

2- Perform at least 3 purge with the reference fluidics and observe that the IPA is getting out from the waste line accordingly without sputtering or air in the system.

3- Set reference fluidics to infuse at 20 uL/min and conduct visual inspection whether you have fluid coming out.

4- If OK, reconnect the PEEK tubing (ID/OD, 0.004/0.0625 inches) at port 4 of the reference select valve and check again that fluid is coming out.

         Perhaps trim couple of centimeters at each end of the black PEEK tubing

5- Stop infusion and refill, then check whether there are any delay. If yes, try to time how long is that delay.

6- If no delay, replace the 100% IPA by MS grade 50:50 water:methanol mix

7- Purge the wash through the reference fluidics three times with the 50:50 water:methanol mix and ensure the mix gets out from the waste line without sputtering or air in the system.

8- Place 100% IPA in the Reservoir B (where we expect the lockmass solution to be located), and purge three times the reference line.

9- Set the reference pump to flow at 5 uL/min and assess how the IPA is flowing out from the PEEK tubing.

10- If ok (without air bubble and sputtering), purge once or twice the reference fluidics with the relevant lockmass solution in use and reassess flow out the PEEK tubing once it is set to 5 uL/min.

11- Assess the flow again and check that it is air-free.

If any issue are appearing from Step 8:

• • Locate a orange tubing (ID/OD 0.020/0.0625 inches, 680 mm of length) from the spare MS fluidics kit
  • Disconnect the tubing from the reference select valve port 2
  • With the spare tubing, you may bypass the access to the reservoir B by creating another access to a reference solution container/bottle placed on the MS solvent tray.

ADDITIONAL INFORMATION