Cleaning glass inlet?

[Irina]

Hi

Can anyone tell me how to clean the inlets used (the ones with glass wool) for reusing?

thank you

[DR]

Generally - pitch the old wool, thoroughly clean the inlet liner as you would other glass labware (soap, hot water, acid rinse, DI rinse, don't scratch the inside) - then you probably have to silanize it (directions should accompany the silanizing reagent of your choosing) and replace the (pre silanized) glass wool. If you don't need silanization, just get it very clean & dry.

Remember, most inlet liners are not all that expensive, so try not to spend too much time on it before just ordering a replacement (or 3).

(It has been just about forever since I've had to do this, so I won't feel bad if corrected by someone w/ more recent experience/expertise).

[Irina]

Thank you for answer. In Europe they are pretty expensive because we have to import it and for now I'm not allowed to spend money

I have the deactivated glass wool. I need only to clean the glass part

[Consumer Products Guy]

I'm not allowed to spend money

It's tough to do good science and be cheap both, ask your supervisor whether he/she wants good results or bastardized results.

Re-read DR's post, you can physically clean, then repack with deactivated/silanized wool, but if you don't deactivate the glass itself, you may compromise your situation and your chromatography.

[Irina]

I will try to clean it. If I won't succeed I will definitely buy another one. But if I can reusing them is better.

One more question. I only work on GC for a few months and I don't know what are exactly the signs that the problem is the inlet. I change it because my software told there were more injection made than the set value( which is 500). I know that when the septum is used the peaks had a tail. Which are the signs for the inlet?

[Consumer Products Guy]

I know that when the septum is used the peaks had a tail. Which are the signs for the inlet?

We use a new septum each Sequence of samples or each day. One can physically look at the liner's glass wool and see if there are any septum particles that have fallen on it, or if it looks brown or black. The best way it sto compare your chromatography (peak shapes/tailing, resolution, etc.) to that which you saved when your system was operating properly. Worse quality chromatography is not a good thing.

Suggest to your supervisor that you would be more valuable if you were sent to a GC training course.

[Irina]

thank you for answers

I don't know if there are such trainings in Romania

[AICMM]

Irina,

Tailing peaks, missing peaks, loss of sensitivity, and extra peaks are all signs that the liner may be dying. If you are running plain old hydrocarbons, you can probably get away with just re-packing the liner, if you are running anything reactive then you really need to look at deactivation. If you deactivate, make sure you use both methanol and non-polar solvent like hexane to deactivate. Also, pay very close attention to how much wool you use as this can lead to extra activity in the liner.

Best regards.

[Don_Hilton]

Also, if you put deactivated glass wool into the liner - you do not have deactivated wool any more. The physical manipulation of the wool causes some fibers to break and more active than just glas is freshly broken glass...

If you are running compunds that give problems with activity - you need to deactivate the liner after the glass wool is inserted.

And, take a good look around to see if there is a vendor who will sell locally made liners that will fit your instrument - and work well.

[qcChemist]

I usually won't clean them, when they get to dirty, I just replace them. I think attempting to clean just introduces more chances for contamination. Restek has them quite cheap. Just order new ones.

[thohry]

I usually won't clean them, when they get to dirty, I just replace them. I think attempting to clean just introduces more chances for contamination. Restek has them quite cheap. Just order new ones.

Unless your analytes are quite inert, it's not a good idea to reuse liners

[greta]

Hi,
Usually I remove the glass wool from the liner. I put the liner in a tube full of acetone: I leave the tube for 10' in an ultrasonic bath. Then I make dry the liner. I put a new piece of silica wool in the liner.

Besides remember to change the septum every 100 injections.

Greta

[DR]

Also, if you put deactivated glass wool into the liner - you do not have deactivated wool any more. The physical manipulation of the wool causes some fibers to break and more active than just glas is freshly broken glass...

Ah - exactly the sort of thing I figured I'd missed!

[haiedc]

Also, if you put deactivated glass wool into the liner - you do not have deactivated wool any more. The physical manipulation of the wool causes some fibers to break and more active than just glas is freshly broken glass...

Ah - exactly the sort of thing I figured I'd missed!

Yes, that's very good idea of Don. So we have to manipulate very carefully even with new glass wool.

[bisnettrj2]

For some very cheap training/troubleshooting help, Agilent has some GC maintenance and troubleshooting videos on its website:

http://www.chem.agilent.com/en-US/Suppo ... ideos.aspx

Also, if your company has many GC analysts, it could be beneficial to contact your instrument manufacturer or an independent consultant to conduct an on-site training seminar for the group.