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1,4 dioxane peak splitting when changed to liner with wool
Posted: Wed Apr 03, 2013 4:17 pm
by nancymdavis
I am running a pulsed splitless injection. I just recently started using a liner with glass wool. The first 10 analytes have peaks that are splitting or have jagged tops. What can I do to eliminate this?
Re: 1,4 dioxane peak splitting when changed to liner with wo
Posted: Wed Apr 03, 2013 5:12 pm
by Steve Reimer
Try less glass wool. If that reduces the splitting, try increasing the pulse time.
Is your inject temperature well above the solvent boilng point or is it a cold injection?
Re: 1,4 dioxane peak splitting when changed to liner with wo
Posted: Wed Apr 03, 2013 7:27 pm
by nancymdavis
The injection port is at 280 at injection.
I just tried increasing the pulse time from 0.25 to 0.30 and there was no change.
I am using liners that come with the wool already packed. I'm not sure that if i took some wool out that i could be consistent.
Re: 1,4 dioxane peak splitting when changed to liner with wo
Posted: Thu Apr 04, 2013 6:43 pm
by Steve Reimer
Do you have a retention gap (short piece of uncoated column) or other extra volume?
My first thought was that you are getting some extra retention in your inlet, a leak or extra volume would do that. If you have solvent condensing at the head of your column it can cause problems with peak shape in early eluters.
If you try it with a small split does the problem go away?
Does your liner have enough volume to hold the vapor on injection? A different liner with wool may not behave the same.