Dear all,

what are the community thoughts on which acid to use to pre-acidify
water samples planned for DOC extraction: HCl. H2SO4, H3PO4? I have
seen them all used.  Which is most friendly on the CF-IRMS glassware?
Also, acidify before or after filtering? To what pH ?  At least if it
is after filtering  and DOM ppts. (such as humics at pH 2), then it
can still be recovered as part of the sample.
Are there concerns about loss of acid-sensitive material from the pool?
Extracting only the HMW pool will eliminate the need for
acidification -yes?- but what if you are interested in the whole pool?

Dr. Susan Waldron,
NERC Advanced Research Fellow,
Centre for Geosciences,
Dept. of Geography and Geomatics,
University of Glasgow G12 8QQ,

Tel: 0141 330 2413
Fax: 0141 330 4894
email: [log in to unmask]