[NHCOLL-L:4492] Re: resitivity for water used in wet collections?

[John E Simmons]

You don't need super-clean water, as you are not using sterilized
containers, etc.  What you need is water with enough of the minerals and
salts removed that you don't have precipitation problems.   The sink system
should be sufficient.

I am curious as to why you are standardizing to 75% ETOH instead of 70%
ETOH,

--John

2009/9/1 Opitz, Cindy <cindy-opitz at uiowa.edu>

>  I'm new to processing wet collections--not a collector of new specimens,
> but faced with transferring existing collections into newer fluids, due to
> evaporation, etc.  I understand the transfer process, and I've been told I
> should use de-ionized water, but I'm unclear about what resistivity is
> desired for the de-ionized water we mix with ethanol for our storage
> solution. I have available to me a Type I system, including a sink spigot
> with water reading 13-15.4 MΩ, and a wall box that filters the same water to
> a reading of 18.3 MΩ.  Are both appropriate for using in storage (with
> ethanol) of natural history specimens, or do we really need that extra boost
> to an 18+ reading?  The sink spigot would fill our water container about 20
> times faster than the wall box.
>
> Our wet collections include leeches, crayfish, small rodents, reptiles, and
> amphibians, which have been collected over the past 150 years and until now
> have been stored in a variety of fluids (70% EtOH, 95%, and some
> formalin-based).  We're standardizing to 75% EtOH.
>
> I'm grateful for any advice you might offer!
>
>
>
> Cindy Opitz
>
> Collections Manager
>
> Pentacrest Museums: Museum of Natural History
>
> and Old Capitol Museum
>
> 11 Macbride Hall
>
> The University of Iowa
>
> Iowa City IA 52242
>
> 319-335-0481
>
> www.uiowa.edu/~nathist <http://www.uiowa.edu/%7Enathist>
>
> www.uiowa.edu/~oldcap <http://www.uiowa.edu/%7Eoldcap>
>
>
>



-- 
John E. Simmons
Museologica
128 E. Burnside Street
Bellefonte, Pennsylvania 16823-2010
simmons.johne at gmail.com
303-681-5708
www.museologica.com
and
Adjunct Curator of Collections
Earth and Mineral Science Museum & Art Gallery
Penn State University
19 Deike Building
University Park, Pennsylvania 16802-2709
jes67 at psu.edu
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