Yeah.. half-price brown caps (still got most of the batch in the back of a
drawer after working out that they leaked). Also we had a problem with some
round bottomed extertainers that we obtained from somewhere with most / all
caps even though they were supposed to be compatible. Otherwise we use blue
or white caps with few problems.

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 Robert van Geldern
Sent: Wednesday, 31 October 2007 12:01 AM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Exetainer Leakage?


Penny Higgins wrote:

> Just for curiosity, did you change cap colors?
 > It's bizarre, but I don't think I'm
> the only one who's ever noted this.

> I, for one, don't trust the white caps. I only use them for testing.
> Blue caps are OK most of the time. Green caps work the best for us. I
> don't think I've ever had a green cap leak. I haven't tried any other
> colors - but I need to order some more soon. I think I'll go with green.

We tested white, blue and brown (brown were on sale for half price; now
I know why...).

The blue caps worked fine with the flat bottom soda vials for 18O water
analysis and fit more or less (push it!) on the round bottom
borosilicate vials (old and new thread). For the flat vials we stay with
the blue caps.

The brown caps did not fit at all, but once the cap made it on the vial
(push it harder!) they did not leak. In contrast to Penny the white caps
seems to fit very good on the new thread boro vials (and can also be
used on the flat vials). We haven't tested the green ones, however...

regards,
Robert

--
Dr. Robert van Geldern
Section 3: Geochronology and Isotope Hydrology
Leibniz Institute for Applied Geosciences (GGA-Institute)

GEOZENTRUM HANNOVER
Stilleweg 2
30655 Hannover, Germany

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