[NHCOLL-L:4365] Re: how to dissolve and puffer paraformaldehyde in the field?

[John E Simmons]

I have not had tried using paraformaldehyde myself, but I did review the
pertinent literature was reviewed in my 2002 publication, *Herpetological
Collecting and Collections Management*.

Taub (1962) recommended using sodium hydroxide and hot water, but this
produces formaldehyde with a pH of 12.  Huheey (1971) suggested calcium
carbonate, which eliminates the need for very hot water, but produces
formaldehyde with a pH of 11.6.  Alconox dissolves the paraformaldehyde
easily, but Nelson and Sparks (1999) cautioned that the resulting solution
will cause clearning and loss of pigments.

Ehmann (1989) suggested preparing dry chemicals to take in the field as
follows:
1.  A plastic bag containing 80 g of paraformaldhyde, 20 g of anhydrous
sodium carbonate, and 0.5 g of a wetting agent (a detergent).
2.  A second plastic bag containing 21 g of citric acid.
In the field, mix the contents of the first bag with 2 liters of water,
stirring constantly until it is dissolved, then agitating the mixure
periodically over the next 4 hr at 20-30 C.  After this, add the contents of
the second bag, stir for 5 minutes, and allow the CO2 gas to escape for 24
hr.  The resulting mixture will be a 10% concentration of formaldehyde with
a neutral pH

Ehmann, H.  1989.  Neutral paraformaldehyde solution for field use.
*Herpetological
Review* 20(2):44-45.

Huheey, J. E.  1971.  Concerning the use of paraformaldehyde as a field
preservative.  *Copeia* 1963(1):192-193.

Nelson, D.W. and J. Sparks.  1999.  Paraformaldehyde/Alconox problems.
 *Curation
Newsletter* 12:1-2.

Taub, A.M.  1962.  The use of paraformaldehyde as a field preservative.  *
Copeia* 1962(1):209-210.

I hope this information is of use.

--John

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

On Wed, Jun 24, 2009 at 2:59 AM, Dirk Neumann <Dirk.Neumann at zsm.mwn.de>wrote:

> Hi all,
>
> for our next field trip to Africa we are considering to fixate specimens
> with puffered paraformaldehyde solution; to carry cristalline
> paraformaldehyde is onboard of aircraft is  100 % conform with IATA
> regulations and thus avoiding difficulties of liquid formalin solutions (to
> carry solutions with concentrations < / = 10 % is uneffecetive in terms of
> fixations effort per carried quantity).
>
> For puffering, the "Fish Collection Methods and Standards" recommend to
> puffer 16g paraformaldehyde with 4 g anhydrous sodium carbonate and dissolve
> in 400 ml distilled water to have a 10 % buffered formalin solution (refers
> to McAllister, 1965).
>
> Do you have experiences with this method or are there any other methods to
> solve and puffer paraformaldehyde ?
>
> Thanks for your comments & help
>
> Dirk
> --
> Dirk Neumann
>
> Tel: 089 / 8107-111
> Fax: 089 / 8107-300
> email: Dirk.Neumann(a)zsm.mwn.de
>
> Postanschrift:
>
> Staatliche Naturwissenschaftliche Sammlungen Bayerns
> Zoologische Staatssammlung München
> Dirk Neumann, Sektion Ichthyologie / DNA-Labor
> Münchhausenstr. 21
> 81247 München
>
> Besuchen Sie unsere Sammlung:
> http://www.zsm.mwn.de/ich/
>
> ---------
>
> Dirk Neumann
>
> Tel: +49-89-8107-111
> Fax: +49-89-8107-300
> email: Dirk.Neumann(a)zsm.mwn.de
>
> postal address:
>
> Bavarian Natural History Collections
> The Bavarian State Collection of Zoology
> Dirk Neumann, Section Ichthyology / DNA-Lab
> Muenchhausenstr. 21
> 81247 Munich (Germany)
>
> Visit our section at:
> http://www.zsm.mwn.de/ich/
>



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