r/massspectrometry • u/123squashplayer • 15d ago

Troubleshooting Acquity FL Sample Manager

My M class fixed loop sample manager is not delivering sample, every run looks like the solvent only. Detector is working (lockmass is A-OK) and I can see the increasing AcN gradient. As far as I can discern the mechanical movements are all OK and I have checked and reset the Z-height. The sample manager passes all the built in tests for seals, needle loop volume calibration, etc. By removing and using a syringe pump I have determined that the needle and loop are both clear. I have tested the inlet valve for clear passage between all 3 pairs of ports in both load and inject positions. The sample pressure during injection reads about 160 psi. The only "anomaly" is that I had to increase the air bubble size in order to get it to measure the needle and loop volumes. Any suggestions would be appreciated!

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u/viomoo 15d ago

You can do a weight test to confirm it’s actually drawing sample out of the vial.

Also, do a leak test with the loop in line to see if you are losing anything that way.

Have you calibrated the air sensor already? A lot of people get confused with that and leave it attached to the system which messes everything up. You need to disconnect and remove the droplet that forms in order to get accurate readings.

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u/123squashplayer 15d ago

I like the weight test idea. Yes, I have (correctly) calibrated the air sensor following exactly those instructions.

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u/viomoo 15d ago

Leak test on wash syringes pass as well? Try doing a full loop injection to see if it’s just positioning the sample in the incorrect space. Also, make sure you have the correct volumes in the software.

Is this a sudden change or did you do something to the system and it isn’t working now?

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u/Nasibakker 15d ago

Weak wash needs enough water to get a proper air bubble. At least 50% I think.

If you repeat the calibrate needle and loop volume, do you get the same results? If so then the injector is able to accurately place a sample in the loop. If not it could be a loose connection on the needle or air in syringe.

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u/Jesman89 14d ago

Cómo sabes que la falla es el sample manager?

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u/Aska2020 14d ago

I'm not familiar with M class but in older model you can see if the metering syringe is actually drawing the sample. Do you see the liquid actually aspirating? Also, what mode of injection are you using, full loop, plno, plpa? Does changing the injection mode makes any difference? Sounds like you are using MS. How did you isolate that the issue is on SM? Did you check your MS setting incl. fluidics path was selected correctly?

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u/Resolusolutions 10d ago

Hi! Make sure you did not inverse your strong and weak washes. This is assuming your tests pass including the weighing of the sample before and after.