apci tuning issue & nebulizer needle and ferrule connection

Hi. Our lab has a HPLC/APCI-MS instrument running for couple of years. Recently, the tuning became an issue - no peaks coming out but noise. Usually after changing the APCI tuning mix, flushing and after 2-3 of dual tuning came out okay.

When I check the nebulizer spray it looks fine. 

So I thought the nebulizer needle was corroded so decided to change it. But then I thought the old nebulizer needle should be compressed by the ferrule at the end of the needle holde it but it was loose and the needle came out easily. Does this mean the old needle wasn't compressed by the ferrule? Can this cause the issue?

I would like to ask if anyone had this issue or advise. Thank you.

  • Ok. So it sounds like some progress to get the negative mode tune to complete and look ok. I would run the negative tune only. Let it complete and save the tune file. Then run a positive polarity tune immediately. 

    If that fails again, its probably worth logging a service call since there could be a voltage missing in positive polarity that's working just fine in negative.

  • Dear Dannymobbs.

    Thank you for your reply again. We cleaned the (recent) capillary by following your procedure and steps where you mentioned to be extra cautious. After that, we pumped downed that MS. It was the same as usual so we let the MS equilibrate over the weekend. 

    I was excited to check the turning this Monday, but unfortunately, when I was about to bake the MS, I realized the quat pump panel didn't turn on. I first thought it might be the fuse. 

    So I called the Agilent tech support and followed what they recommended. Checked the power plug, swapped it with the plug that was connected with the autosampler (which was able to turn on). When I click the power button of the quat pump, green light came on, then quickly died. I also plugged the cord into the wall but was the same. Hold the button for few seconds but didn't show any light on the upper right corner.

    Tech support suggested that the power supply in the back is the issue. 

    One troubleshooting came across another bigger troubleshooting.. But I really appreciate your kind reply and guiding me through which I learned a lot. Thank you very much.

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