Archival storage of water samples

Mike Howe <mhowe [at] bgs__ac__uk> writes

>I am responsible for an archive of water samples, mostly collected
>from water wells, boreholes and streams. They have already undergone
>a variety of chemical analyses, but are archived for possible future
>additional testing. We currently store them in a dark refrigerated
>room at 4 degrees Centigrade.
>
>Can anyone advise on current best practice, or suggest appropriate
>publications?

As part of the Canadian Conservation Institute's manual for the
workshop on The Conservation of Wet Archaeological Artifacts
(October 18-21, 1999) I prepared a section "Monitoring Treatment
Solutions: Chlorides, pH, Conductivity and other Parameters."
Included in this section is a discussion of sampling considerations
(volumes required, storage containers, sampling time between
collection and analysis, etc.) and general guidelines on the
preservation of water samples prior to analysis. Storage conditions,
temperatures, preservation methods (additives), allowable storage
times all vary depending on the parameter which is to be analysed
and the original volume of the bulk sample.  Analysis of samples
after the allowable time can result in less reliable or incorrect
results because samples change with time due to adsorption onto
container walls, off-gassing, biological alteration of samples, etc.
My sources of information were classic publication that included
"Sampling for Water Quality" (Ottawa: Supply and Services Canada,
1983).

I would recommend that you look for similar publications used in
Britain that are produced as guidelines for scientists in the
water-sample analysis business, or someone in the chemistry
department of a local university who carries out water quality
testing routinely. It is best to use more than one source for
information as they sometimes give different recommendations. If you
contact me off-list, I will be pleased to send you a copy of the
section listed above from our workshop, although the practices used
for the  long-term storage of geological water samples may differ
from those as listed in the workshop manual.

Nancy E. Binnie
Conservation Scientist (Chemist)
Conservation Processes and Materials Research
Canadian Conservation Institute
Department of Canadian Heritage
1030 Innes Road, Ottawa, Ontario
Canada K1A 0M5
613-998-3721
Fax: 613-998-4721


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                  Conservation DistList Instance 16:53
                  Distributed: Tuesday, March 18, 2003
                       Message Id: cdl-16-53-004
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