[Nhcoll-l] Fluid preservation jar lids

[Joachim Händel]

I've also had very good experiences with  cotton wool (purified cotton
wool for medical use).
I would be careful with synthetic cotton wool because it might be
damaged by additives in the alcohol - denaturants (e.g. Butanone -
methyl ethyl ketone / MEK). This is only a suspicion and not proven.

All the best and much success

Joachim






--  
Joachim Haendel
                                                       
Center of Natural Sciences Collections
of the Martin Luther University
- Entomological Collection -

Domplatz 4
D-06099 Halle (Saale)
Germany

Phone:  +49 345 - 55 26 447
Fax:  +49 345 - 55 27 248

Email: joachim.haendel at zns.uni-halle.de




>>> Callomon,Paul 17.08.2022, 02:18 >>>
I agree with Rob; we could not find any account of cotton deteriorating
in ethanol, nor any chemical reason why it should. We have used it as an
internal divider in shared containers for more than a century. The
problem of picking up spines can be partially mitigated by tightly
rolling the cotton into a sausage, then bending it double and sticking
the doubled end into the vial and ; that way, the part facing the
specimen is a smooth wall of curved fibers, not an open brush.











Paul Callomon
Collection Manager, Malacology and General Invertebrates

Academy of Natural Sciences of Drexel University, Philadelphia
callomon at ansp.org Tel 215-405-5096 - Fax 215-299-1170



From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> on behalf of Robert
Waller <rw at protectheritage.com>
Sent: Tuesday, August 16, 2022 7:25 PM
To: nhcoll-l at mailman.yale.edu <nhcoll-l at mailman.yale.edu>
Subject: Re: [Nhcoll-l] Fluid preservation jar lids



External.

Our field has conflated the idea of wood products becoming acidic over
time with pure cotton (cellulose) becoming acidic over time. It is the
lignin content of wood that becomes acidic, and in some cases additives
to paper, that become acidic over time (through oxidation and/or
hydrolysis). Pure cotton itself is not expected to become acidic over
time except by transfer of acidity from adjacent components and even
that is questionable. Certainly, in fluid preserved collections there
are many components that will react with oxygen before cellulose gets a
chance. These include residual formaldehyde from fixation, oils, fats,
and other organic constituents  from specimens, and even ethanol itself –
consider the wine into vinegar process.

Pure cotton presents no risk of acidification, although it may present
problems of catching on complex surfaces.

Rob

 

lete saatja õigsuses ja sisu turvalisuses kindel.
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