Periodic reference ion dropout

Instrument = 6550 QTOF

I'm experiencing consistent reference ion drop-out at shifting 6.5 minute intervals. I've attempted to flush the reference line with water, IPA, MeCN but the issue still persists. This seems like a possible mechanical issue. I'm pulling my hair out on a fix. Has anyone experienced this before?

  • I recall seeing this a few years ago on our 6545 QTOF. It turned out for us, the reference line tubing going into the nebulizer was loose. All we had to do was unscrew the connection, make sure the tubing was snug against the back of the port and then screw the fitting back on.

    Not sure if the reference bottles are set up the same way on yours, but we were also shown in our install training to check the liquid in the bottle should be still as the pressure is applied to inject the reference solution -- if it's rippling, that was indicating a leaky connection to the bottle cap. We were also taught to detach the line from the nebulizer and count the number of seconds between drops to make sure the flowrate is OK and there's no tubing clog.

  • Yes, I forgot to update the post as solved. You had a good hunch about a loose connection! We removed the reference nebulizer to inspect the capillary and the tiny lock screw on the assembly was loose. Once the out nuts were loosened the capillary slide right out with almost no force. After reinstalling and tightening all screws the drop out was resolved. 

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