Hi'
We have found that condensation occurs more often with samples that have not
been run promptly either after being initially dispensed into the gasbench
vial or after equilibration with co2 - we now make sure that whole analysis
goes through without pause.
We also keep the sample tray as close to room temp as it can get, to avoid
having the room much colder than the block, which could promote condensation
under the cap.
Also experimented with reversing the connecting tubes to the needle - a
hanging drop is going to be forced into the point of the needle if the
carrier is supplied from the side hole. This seemed to work well at a time
when we were having problems, but I think the timing and temp factors are
more critical and we have currently got it set up in the way it was
originally.


> -----Original Message-----
> From: Stable Isotope Geochemistry
> [mailto:[log in to unmask]] On Behalf Of Gerard Olack
> Sent: Thursday, 15 December 2005 4:27
> To: [log in to unmask]
> Subject: Re: [ISOGEOCHEM] Condensation of sample water on septum
> 
> Hi Magda & Diana--
> 
> After equilibration, we've taken to removing taking the tubes out (two 
> at a time) and tapping the sides of the cap to move the condensate to 
> one side, then shaking it down.  There isn't much of a problem with 
> the runs afterwards.
> Alternatively, you may consider putting a blanket on top of the 
> gasbench while it's equilibrating to see if that cuts down on 
> condensation.
> 
> take care
> 
> gerry
> 
> Diana Bojic wrote:
> 
> > Dear All,
> > We are new in mass spectrometry "business" but we already have 
> > problems. We are trying to do water equilibration on gas
> bench II and
> > delta +XP. We have problem with evaporation of sample water
> in vials.
> > Water is condensing on the septum and when  the needle penetrate in 
> > septum small amount if water is  entering the system.  We
> have heard
> > for building a cooler but we are interesting in otherer
> possibilities.
> > Does anybody have some suggestions? 
> >
> >  
> >
> > Thanks
> >
> >  
> >
> > Magda & Diana
> >
>