[NHCOLL-L:1279] Re: Fwd: formalin? Gasp!

[Elizabeth A. Moore]

Instead of testing for the presence of formalyn (which almost all specimens
have from fixing whether or not they are stored in it), is there a way to
test for the presence of alcohol?  We have some old specimens where the
formalyn/alcohol has evaporated and we have a very dilute (mostly water)
fluid left.  Since the specimens were fixed in formalyn there will be traces
left but what I can't tell is were they then stored in alcohol or not?  Is
there a test for alcohol (either iso or eth)?

We density test the iso solution to correct fluids when we know the fluid is
actually supposed to contain iso but when the fluid is old and unknown "tis
a puzzlement."

Also, what is the best way to test ethanol solutions for percentage of eth
in water?  We use density to test percentage of iso solutions.

Elizabeth Moore



----- Original Message -----
From: "Amy Estep" <aestep at ou.edu>
To: <nhcoll-l at lists.yale.edu>
Sent: Tuesday, October 16, 2001 9:15 AM
Subject: [NHCOLL-L:1278] Fwd: formalin? Gasp!


> Thank you for all of the great responses and suggestions.  I will try the
> hydrometer method described on the list by Steve Rogers since I have one
on
> hand.  Also, the message below was sent to me by Simon Moore in which he
> describes a specific gravity meter that he developed using map pins and a
> bottle dropper (see Carter and Walker's 1999 book, Care and Conservation
of
> Natural History Collections).  I tried this method recently with no
success but
> will try again with different map pins...the pin heads I used on the first
> attempt sank in both 10% formalin and 70% ethanol.
>
> Cheers and many thanks,
> Amy
>
>
>
> "Moore, Simon" wrote:
>
> > Dear Amy Estep,
> >
> > Your enquiry was forwarded to me as I specialise in fluid preservation
> > problems.
> >
> > I have tried leuco-basic fuchin impregnated papers but if they test
> > positive, the pink dye can colour the fluid and no matter how careful
you
> > are using forceps and gloves, the dye gets on hands at some point and
looks
> > most unattractive!  Also, such papers need to be stored in the dark and
have
> > a limited shelf life.
> >
> > So I devised a specific gravity test using map pin heads.  Details are
in
> > Care and Conservation of Natural History Collections, 1999, Eds. Carter
DJ &
> > Walker A, Butterworth Heinemann: 100-101,  Basically it just involves
> > pulling the heads off two differently coloured map pins (or how many you
> > wish to use to distinguish fluid specific gravities) and then push back
into
> > the head enough of the pin so that it will float in fomalin and sink in
> > alcohol - other pins can also be adjusted to distinguish between lower
grade
> > alcohols (following evaporation?), formalin and full strength alcohol.
If
> > you can get hold of a dropper bottle with a reservoir (as shown in the
book)
> > it looks neater.
> >
> > Hope this will help and keep your Health & Safety Officer happier.
> >
> > With all good wishes, Simon Moore.
>
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Amy D. Estep
> Curatorial Specialist in Herpetology
> Sam Noble Oklahoma  Museum of Natural History
> University of Oklahoma
> 2401 Chautauqua Avenue
> Norman, OK  73072
> v:  405-325-1516
> f:  405-325-7771
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>