Penny (& others)

We just make our own from teflon rod cut into ~1 cm sections and then
drilled out. From memory the rod was 5 mm diameter and we drilled a well of
~3-4mm, smoothed the insides, and left a ~3mm base. I think that it is what
we had in stock and it took our workshop a couple of hours to make us a
lifetime's supply using a stand mounted drill and a saw. This holds ample
acid and is easy to load using a pair of tweezers. I'm not sure that teflon
is absolutely necessary - it's just easy to work with, robust, and cleans up
well. The prototypes for this were the end caps on ballpoint pens! (which
worked OK for a couple of runs while we were playing with the techniques).
The one thing that is really needed is the small piece of rod (we use the
capillary tubes used to draw blood) the acid to break the surface tension.

Hope that that helps.

Ian

_______________________________________________
Dr Ian Cartwright
Head - School of Geosciences
Hydrogeology and Stable Isotopes
Monash University
Clayton Vic. 3800, Australia
t: 03 9905-4887 / 4879, f: 03 9905-4903

...water, our greatest resource


-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]]On
Behalf Of Penny Higgins
Sent: Wednesday, 22 June 2005 11:30 PM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Continuous Flow Carbonates


I went to the ISOGEOCHEM archives and read a bit of the thread on this.

Just for curiosity, and because I'm only just getting the hang of this, how
might I get my paws on teflon boats (for acid) that will fit in the
exetainers? I've been running my GasBench for about two weeks now, and am
already getting annoyed with the whole acid delivery problem. I expect it
will only get worse once I start running apatites instead of carbonates.

Thanks,

~Penny

At 06:42 PM 6/21/2005, you wrote:
>All
>
>We encountered different problems with acid delivery on our gas bench
>(mainly acid reacting with the septa and clogging the extraction needles)
>and went to a system where we introduced the acid into the exertainers in
>small cups that we then tipped following flushing. There was e-mail traffic
>on ISOGEOCHEM on this topic some time ago (including a description of the
>method) which should be in the archives. Other groups had come up with
>similar solutions. We have played around with various variations, and in
the
>end sacrificed the elegence of doing the whole acidification-extraction
>process fully automated for a method that we have found to be robust.
>
>Ian
>
>_______________________________________________
>Dr Ian Cartwright
>Head - School of Geosciences
>Hydrogeology and Stable Isotopes
>Monash University
>Clayton Vic. 3800, Australia
>t: 03 9905-4887 / 4879, f: 03 9905-4903
>
>...water, our greatest resource
>
>

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                             "SIREAL"
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