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PTV as classical split injector ?

Posted: Fri Apr 21, 2006 6:16 am
by kurtdm
Dear all,

Since i do not have practical experience with PTV injection, this might sound naive, but i was wondering if a PTV injector, in its hot split injection mode, leaving the split vent continuously open and introducing the sample into a hot inlet, can be used or seen as a classical split injector?

Thanks for your comments.

Best regards,
Kurt

Posted: Fri Apr 21, 2006 7:02 am
by Peter Apps
Hi Kurt

Simple (simplistic !!) answer: Yes, but with all the foibles and idiosyncracies of an ordinary split-splitless.

Most (all ?) PTVs have smaller liners than the dedicated split inlets so there might be some issues of vapour volume and heat transfer.

Give it a try and let us know how it goes.

Peter

Posted: Fri Apr 21, 2006 2:02 pm
by Ron
In my experience fairly volatile compounds (C20 or less) at a relatively high concentration and a high split ratio work best when using a PTV as a split injector. The liner volume is usually very small, so you need a high flow through the liner to minimize overloading of the liner.

Posted: Mon Apr 24, 2006 7:46 am
by chhubert
Kurt,

The vapor volume of the injected sample can be estimated from a GC Pressure/Flow calculator software downloadable in Agilent's website. The calculator is fairly useful as a hint on how much volume you could inject in different size of liner at different column head pressure and inlet temperature.

http://www.chem.agilent.com/cag/servsup ... s/GCFC.htm

Hope this helps.

Posted: Fri Apr 28, 2006 5:21 pm
by L4br4t
Kurt,

The vapor volume of the injected sample can be estimated from a GC Pressure/Flow calculator software downloadable in Agilent's website. The calculator is fairly useful as a hint on how much volume you could inject in different size of liner at different column head pressure and inlet temperature.

http://www.chem.agilent.com/cag/servsup ... s/GCFC.htm

Hope this helps.
Yes, follow this advice. Kudos Chhubert!
This is a necessary tool for ALL chromatographers.