Dear Orfan

I am pleased to learn that some-else has taken a liking to the Mn
method and generates good results.

I quite agree with your assessment re the importance of grain size.
I never got the hang of mesh sizes but in metric the particle size
should predominantly be 100 - 200 micrometers. Anything finer
than that does produce funny results, the Mn powder cakes and
becomes lumpy, which if course changes its surface area and
properties.


Best wishes - and thanks,

                          Wolfram


> Dear Dr. Panarello,
>
> We have been using Mn for H/D analysis for few years now. The results
> are excellent, It's actually better than the Zn technique that we used in
> the past.
> When we first started using the Mn, we did the preparation off line in
> vessels (800 mg of Mn and 8 microliter of water at 525C for 50 min).
>
> More recently, we developed an on-line technique for H/D analysis by
> Mn, it works for water, natural gas and organic solvents.
> reaction time is 20 sec. for water, 4 min for natural gases and 9 min. for
> organic solvents at 900C . Reproducibility is better than 1.8 ‰ in general
> and better than 1.5‰ in water samples.
> Please note that the Mn bead size should be between 60-200 mesh, any
> mesh size out side that range doesn't seem to work.
> The paper that describe the technique was accepted by Analytical
> Chemistry and it should be published soon.
> In the mean time if you need the technique and preprint, I would be glad
> to send it to you.
>
> Best regards,
>



*****************************************************
Dr. W. Meier-Augenstein, CChem MRSC
Senior Research Fellow

University of Dundee, Dept. of Anatomy & Physiology,
OMS, DUNDEE  DD1 4HN, United Kingdom

Tel. (B): +44-(0)1382-34/5124 or /4574
Fax  (B): +44-(0)1382-34/5514

e-mail (B): [log in to unmask]

URL: http://www.dundee.ac.uk/anatphys/wma/meieraug.htm
*****************************************************