>Dear All:
>
>I will be very grateful if somebody can give me suggestions or references
>as how to extract water from alunite, K2SO4.Al2(SO4)3.4Al(OH)3, for D/H
>and 18O/16O analysis. I tried vacuum distillation at 550 degree C. Instead
>of pure water, I got sulfuric acid with very strong smell of SO2.
>
>Best regards.
>
>Dachun Zhang
>


Dear Dachun,

I posted a question regarding Alunite around mid-December last year, and
got some very helpful answers, some from Greg Arehart, who has already
responded to you; some by Bob Rye and others.

The methodology for stable isotope analyses of several sites in alunite is
described in


Wasserman, M. D., Rye, R. O., Bethke, P. M., and Arribas, A., 1992, Methods
for separation and total stable isotope analyses of alunite:  U.S.
Geological Survey Open-File Report #92-6, 21 p.

A reference for principles of interpretation is

Rye, R. O., Bethke, P. M. and Wasserman, M. D., 1992, The stable isotope
geochemistry of alunite: Economic Geology, v. 87, p. 225-262.

(Kindly supplyed by Bob Rye, and actually forwarded to me by Greg Arehart;
did I ever thank you?).

I suggest that you dig into the Isogeochem web page and look for postings
around 18-20 December 1996 regarding this matter. If you are not succesful,
I keep responses received in file, so I could forward them to you as an
attachement.

I keep working on alunites as time permits, so I would be interested in
sharing experiences.

Cheers,

Clemente


-----------------------------------------------
Dr. Clemente Recio
Stable Isotope Laboratory
Fac. de Ciencias
Univ. de Salamanca
E 37008 - Salamanca
      Spain

Phone: (+34) 23 29 44 00 Ext. 1540
Fax:   (+34) 23 29 45 14
E-mail: [log in to unmask]
-----------------------------------------------