Aninda,
There is a general agreement of sorts, in that the general agreement is that
AVS measurements have no clear meaning. Probably the nicest reference in that
regard if you want to document the difficulties is Morse and Rickard, 2004,
Chemical Dynamics of Sedimentary Avid Volatile Sulfide, Environmental Science
and Technology 38(7):131A-136A.

By the way, extraction is not the only problem. If you use for instance a
sulfide antioxidant buffer to trap then your measurements will vary not only
with buffer strength but also sulfide content, and recovery will be quite
nonlinear for high sulfur samples.
John

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of aninda mazumdar
Sent: Friday, September 22, 2006 12:50 PM
To: [log in to unmask]
Subject: [ISOGEOCHEM] acid volatile sulfur

Dear list members,

It seems there is no general agreement on extraction
of acid volatile sulfur (AVS) from sediments. People
have used (1) cold HCl, (ii) Hot HCl, (iii) cold
HcL+SnCl2 and (iv) Hot HCl+ SnCl2. There are
contrasting views on the use of SnCl2 since it can
affect pyrite and produce artefact AVS. I would
appreciate if you can update me on the status of
experimental method for AVS extraction.

ciao

Aninda Mazumdar

Geological Oceanography
National Institute of Oceanography
Dona Paula
Goa-403004  

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