Dear Rose and Wayne,
Thank you for replying to my question.I'm sorry I forgot to mention our
method of decalcification. In the past we used 5% Sulphosalicylic acid only
to decalcify bone and the fluid turned purple with some of the bones.We now
start off with 10% Nitric acid for a maximum of 48 hours and if the bone is
not decalcified we transfer it to 5% Sulphosalicylic acid until
decalcification is complete and we still get the purple colour with some
bones.
The other strange thing that again only happens occasionally with some
bones is when we are doing the chemical test to determine the end point of
decalcification, when the ammonia is added to the 5ml of decalcifying fluid
it turns to a pale amber colour!
Can anyone offer any suggestions.

Many thanks,

Tony Brandwood,
Dept. of Veterinary Pathology,
University of Liverpool,
P.O. Box 147,
Liverpool,
L69 3BX,
U.K.