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headspace shaking effect

Posted: Mon Nov 26, 2012 1:26 pm
by greta
Dear all,

I 'm looking for a method useful for test the shaking capability of an headspace autosampler.
Could you suggest me a method in which shaking of the sample is very important for the reaching of the equilibrium (equilibrium time is strongly affected by the presence or absence of the shaking)?

Thank you in advance

Greta

Re: headspace shaking effect

Posted: Mon Nov 26, 2012 8:25 pm
by chromatographer1
Any matrix that tends to separate into two phases or is slow to dissolve unless heated at an elevated temperature and shaken would be an example of a good test.

Of course, this is all mute, unless you have evidence that by NOT shaking you have affected the result of your headspace analysis.

Larger samples will show the effect of not shaking more than smaller ones. A simple test of isopropanol in water using different amounts of sample could be the test you seek.

With these points in mind look around your lab and see what you have that would qualify and try them out.

best wishes,

Rod

Re: headspace shaking effect

Posted: Tue Nov 27, 2012 3:17 pm
by greta
Dear Rod
"Any matrix that tends to separate into two phases or is slow to dissolve unless heated at an elevated temperature and shaken would be an example of a good test".

Could you be so kind to give me an example for this?

Best regards

Daniela

Re: headspace shaking effect

Posted: Tue Nov 27, 2012 3:25 pm
by chromatographer1
Candle wax in DMF.

Rod

Re: headspace shaking effect

Posted: Tue Nov 27, 2012 3:35 pm
by greta
Dear Rod,

Do you have a method for Candle wax in DMF analysis to suggest me?

many thanks for your help.

Bets regards

Daniela

Re: headspace shaking effect

Posted: Tue Nov 27, 2012 6:30 pm
by chromatographer1
Sorry. I don't. Do you need one? Really?

Rod

Re: headspace shaking effect

Posted: Wed Nov 28, 2012 8:20 am
by greta
Hi Rod,
Are you jocking me?

Greta

Re: headspace shaking effect

Posted: Wed Dec 05, 2012 8:57 pm
by RogerBardsley
Restek has a guide on headspace at http://www.restek.com/pdfs/59895B.pdf . This might give you and idea for a system that might require shakiing.