On Tue, 11 Jul 2000 18:38:26 +0530 Ravi Bhushan <[log in to unmask]>
wrote:

> Dear Friends,
>
> I am planning to make DOC measurements in river water samples using
> Shimadzu TOC 5000A analyser. One of the basic problems we are facing is
> storage of samples. Can anybody suggest the standard protocol for storage
> of river water samples for DOC measurement.
>
> Thanks
>
> Ravi
>
>
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Ravi,

For DOC analysis samples should be filtered immediately with ashed
.45um filters.  Standard Methods for Water and Wastewater also
recommends refrigeration and addition of HCL to pH<2 for samples which
can't be analyzed immediately.  Maximum recommended storage time is 7
days.

Good luck with your analysis.

Tom


Tom Maddox, Research Coordinator
Analytical Chemistry Laboratory
Institute of Ecology, UGA
Phone (706)542-6023
WebSite http://www.uga.edu/~sisbl/