Chromatography Forum

First post here. Just a quick question. I changed the column, changed the gas and at first everything looked good with the tune. But after the weekend, it started to look like this.




I have disconnected and reconnected everything twice to make sure it wasn't a user error. Anyone know what I could try. Could it be the new gas tank, never had a problem like this before. Seems like only baseline noise is showing up and not the PFTBA.

Thanks in advance,
Goonie

Is your PFTBA vial empty?

I have had what looks like the same problem with a 5973 - the PFTBA valve sticks shut. You can still hear a click as the solenoid activates, but the valve is not opening and all you see on the tune is background noise.

The cure should only be attempted by very expert technicians with years of training and experience; I vented the MS, removed the valve and gave it a sharp tap with the handle of a screwdriver , then put it back. Worth a try at least.

Good luck.

Peter

Could also try the "purge cal valve" option.

Thanks for the advice. I ran some blanks last night and they almost all looked like this. I ran DFTPP and did not see any peaks. If the problem was the PFTBA clogged, I would still see peaks in the runs. Theres something else wrong. I'm gonna be taking it apart and cleaning it soon I guess

Well, after taking apart the source and giving it a good cleaning I finally got my tune back.

The filaments were practically black so I replaced those. I run SVOCs and some of my samples are really dirty and acidic, pain in the rear doing maintenance everyday and replacing the column about twice a month. I guess I'm gonna have to be cleaning the source every few months also.

Thanks again for your suggestions!