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Solution level in vial - GC needle height
Posted: Thu Oct 19, 2017 9:19 am
by ydna1977
Hi ,
We have Agilent 7890B with 7693 Autosampler
Struggling with sample < 0.5ml
How much is required to go into vial ?
ie how far does GC needle go into vial as default setting?
mm away from bottom of vial ?
Currently using standard 2ml vial
I don't want to mess with sampling offset
Thanks
Re: Solution level in vial - GC needle height
Posted: Thu Oct 19, 2017 9:33 am
by tkubowicz
Hello
for Agilent 7693A Variable sampling depth –2 to +30 mm above default
so you can check it.
If your sample is less than 0.5ml isn't it better to use vial with insert?
Regards
Tomasz Kubowicz
Re: Solution level in vial - GC needle height
Posted: Thu Oct 19, 2017 11:59 am
by ydna1977
thanks
by that rationale the needle sits 2mm above bottom of vial when taking a sample ?
Inserts were next option by don't have any available at the moment
Re: Solution level in vial - GC needle height
Posted: Thu Oct 19, 2017 1:16 pm
by Rndirk
3mm is the standard needle depth. Setting the option to -2mm means taking 1mm from the bottom of the vial.
Re: Solution level in vial - GC needle height
Posted: Thu Oct 19, 2017 2:21 pm
by KM-USA
0.5ml should be plenty for a standard vial. One definitely does not want to fill all the way up !
Sometimes we used small-volume vials which had more glass and a cone-shaped inside, so similar to using a separate insert. But most times we had plenty of sample solution so not a common issue in our business.