Hi Group,
Hydrogen peroxide is an oxidizer. That means its purpose is to
oxidize (attack) organic remains, including the seeds and other
organics in your sample.
The first thing that we use is hot water. That disaggregates many
clays. No risk to the samples, since the water is not boiling, but
just hot, as you would use for washing dishes or a hot bath.
If that does not work, we use dilute sodium hexametaphosphate to
disaggregate clays and find it works quite well. Sodahex is a base
(a strong base in concentration), and all bases have the possibility
of attacking organics. So far, we have observed no deterioration of
seeds in samples that we have treated with dilute sodium
hexametaphosphate.
Linda Scott Cummings
>Dear colleagues,
>
>One of the solutions for wet sieving of clayey samples is the addition
>of hydrogen peroxide, which makes the clay desintegrate. I am
>considering using this for a set of Dutch samples, in which the
>preservation of the seeds is of great importance. Does anyone
>know references to studies that deal with the effects of hydrogen
>peroxide on botanical macroremains? If possible not only concerning
>the present or absence of particular species in a comparison of
>treated and untreated samples, but also on the corrosion observed
>in individual seeds? The effects could be both positive and negative,
>as H2O2 facilitates sieving, which might cause less harm to the
>seeds during sieving, but H2O2 may also influence the seeds by
>corroding them...
>
>Many thanks in advance for your reactions,
>
>oTTo
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>
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>***** Rijksdienst voor het Oudheidkundig Bodemonderzoek *****
--
Linda Scott Cummings, Ph.D.
Paleo Research Institute
2675 Youngfield St.
Golden, CO 80401
USA
(303) 277-9848
fax: (303) 462-2700
http://www.paleoresearch.com
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