Sample Injection via valve onto capillary column

Chromatography Forum: GC Archives: Sample Injection via valve onto capillary column
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Wednesday, April 3, 2002 - 08:09 am:

I am using an analyzer that is designed for packed columns. I am interested in adding an accessory oven which has temperature programming capabilities. The accessory oven is designed for capillary columns only. I would like to use this oven for the analysis of C1-C6 using a FID. The would be injected directly onto the column using a sample valve.

I am aware that there are a number of issues that need to be considered. For example, sample size, flow rate, and temperature program. The analyzer does not have a split/splitless inlet. I would like to use a 0.32um capillary column. Any feedback will be greatly appreciated.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Rodney George on Wednesday, April 3, 2002 - 10:02 am:

Please email me for a discussion of your problem.
It is too lengthy to address in the forum.

I will be glad to give you a nickel's worth of free advice.

Been there, done that.

Rodney George

rgeorge@sial.com


Top of pagePrevious messageNext messageBottom of pageLink to this message  By chaiyapon on Wednesday, April 3, 2002 - 10:09 am:

You can inject the gas samples without any inlet but small loop need to connected to 6 ports valve
you can order the small loop from valco company,

sample size 0.05-0.1 microlite.
flow rate of He about 4-6 ml/min for 0.32 umcolumn
temperature 70 oc to 180 oc
column : Plot Al2O3


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Rodney George on Thursday, April 4, 2002 - 05:29 am:

Beware of Alumina plot columns. If you are concerned with measuring Sulfur containing compounds or actylenes (alkynes) with accuracy then Al2O3 columns will be inadequate. They will also give errors if your samples contain water as the peaks will drift and you may misidentify peaks. I have not heard from you, Anonymous. Good luck.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Les on Friday, April 5, 2002 - 09:32 am:

I've used plot colums for 6 years doing LPG and haven't had many problems. I pressurize the LPG bombs with 500PSI nitrogen. Pressurized LPG enters a 0.2 or 0.5 uL Liq Sampling valve from valco. Split injection ports are running 35 to 50 ratio. Aluminum Plot KCl deactivated 50mx530umx15um Al2O3. If water does get on the column, plots can be heated for a few hours.


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