ESI sputtering spray

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

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My spray is not a nice consistent stream and I want to clean the needle that houses the electrode in an attempt to solve the problem.

What is the best method to clean the ESI probe and also is this the most likely culprit to my problem of sputtering spray?

Thank you for any and all input!
To get more accurate help it would help to add which kind of system you are using.

The inside of the needle can indeed get clogged, but there are other sources of this problem. For example, air in your mobile phase flow or inconstant source gas pressure. To isolate the problem I suggest to first infuse some solvent straight into the source. If it is indeed the needle that is clogged, you can run some different solvents through it hoping to unclog it, or you can just put a new needle. My advice is to do the latter if it is a consumable part in your system.
The exact placing of the inner needle relative to the outer one (which conveys the nebulizer gas) can also be important. Since the spray needle is a consumable part, there are certain to be instructions in the instrument's manual on how to replace it. If you haven't got the manual, ask the manufacturer to send you a pdf. This bit of an instrument can vary a lot between manufacturers, so it's definitely best to get the right instructions.
I have a Sciex 5500. I am not sure if it is a consumable part or not.

If I inject sample with a syringe it still passes through the ESI probe so how could that diagnose the problem?
If it doesn't sputter while you infuse a steady flow in the source, it means the problem is on the LC side. If it does, then it is the probe itself.

I haven't worked with Sciex systems but I'm quite sure it's a consumable part on these recent systems. How did you diagnose the sputtering, can you see the spray in your system?
Yes, there is a glass window on the front of the source. I ran PPG earlier this week to check the calibration. I noticed the sputtering on that occasion because my results looked weird. I did not complete the PPG calibration because I figured it made more sense to try and resolve the sputtering issue first.
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