Chromatography Forum

Well this is pretty embarassing. 6890/5973. Overtightended the interface nut, shattering the vespel ferrule. The column broke and now it's stuck inside the interface. Any advice on the easiest way to get the sucker back out? Anything else I need to look out for since this happened?

You can try pushing it out from the inside of the analyzer. I don't know if 1/16" tubing will fit back through there but if you have some 0.53 Metal transfer line http://www.restek.com/catalog/view/32087 something like that, you should be able to use it to push the column out backwards. If there is enough sticking through in the analyzer to get a grip on, maybe you can pull it on through too.

When you get it out, you should run something like a megabore column through there to make sure no ferrule fragments are hanging around in the interface before reinstalling the column.

Thank you James. I was able to get at the column from the detector side and pull it out. There were bits of ferrule wedged inside, but I got those and cleaned everything out with a large column and a stream of nitrogen.

It seems like I'm having trouble getting a good vacuum, though. This is what had led me to trying to tighten the interface nut to begin with. To take a step back, after I installed the column originally I gave it a few hours to pull vaccum, and then heated up the source and did an air and water check. It looked terrible (as in, only a few counts for each target ion) so I turned the source heaters off and vented the system. That's when I discoverd the crushed ferrule. So now, having gotten the broken column out and reinstalled everything, I'm back to trying to figure out whether there's something else wrong that is preventing me from getting a good vacuum. (FYI, I have a turbo pump)

When I start up chemstation the HiVac monitor reads "9.99e+09" and occasionally flashes to read "---". The Micro Ion E Gauge light alternates between red and green.



When I start up chemstation and go to Tune and Vacuum Control -> Vacuum -> Pump down, I get the following text:

"Difficulty with the electron multiplier supply."

And this popup:
"Pump Down Error: MS Status fault 512"

I tried following a couple suggestions I've found online. I've tried plugging the column at the inlet end with a septum. I've also tried just venting it, turning it off, then starting it up again with me pushing on both ends of the door while somoene else hit the on button.

Not sure where else to go from here. Does this sound like a leak or something else?

Update: I no longer get the electron multiplier difficulty or pump down error messages. Still get 9.99e+09 on the vacuum indicator. I thought maybe it wasn't working and tried doing an air and water check - results were discouraging.

69 abundance was 72448
18 was 258880
28 was 61688
32 was 10175

Water higher than nitrogen?

Close the PFTBA in the tune; set the mass range up to 100; and start a scan. Use a can of Dust off and apply it to interface; give it a minute. If you have leak at the interface you will see the extra peaks. You want to repeat this procedure to all locations that has a chance for a leak, including the PFTBA connection (I once had a leak at this location).

Close the PFTBA in the tune; set the mass range up to 100; and start a scan. Use a can of Dust off and apply it to interface; give it a minute. If you have leak at the interface you will see the extra peaks. You want to repeat this procedure to all locations that has a chance for a leak, including the PFTBA connection (I once had a leak at this location).

This is definitely the next step. Also spray it around the end plates of the analyzer, I had one once that had a slight leak and just had to tweak the big screws that hold the rear plate on.

Another spot that can leak that is more difficult to get to is where the interface meets the analyzer chamber, there is an aluminum crush washer there that seals that. We also had one that had a cracked interface right behind the threads where the column nut screws on, could not find it until the end broke off while tightening the nut.

Something as small as lint on the o-ring gasket can also cause what looks like a huge leak, you may want to take the seal out and rub it down with a kemwipe and add some Apezion L grease if you have any.

Remember that the ferrule for the transfer line is "backwards". That is the large end is against the transfer assembly.