Hi Jenny

Here's my tuppence worth, but please take it with a pinch of salt as I do
not claim to be a collagen person!

I think that the material that binds bone together and cartilage are very
similar: Cartilage is often the precursor to bone.  So, I would be inclined
to treat it like bone but probably expect to lose very little.

I wouldn't be surprised if you can run it pretty much as it is, given that
the signatures of most of the components are fairly similar and that
collagen must dominate.  Perhaps try just de-lipifying it and compare the
results with a demineralised version.  Could be a method paper!

Best wishes

Hil

.

Hilary Le Q. Stuart-Williams PhD.
Research Officer in Stable Isotopes
Environmental Biology Group
Research School of Biological Sciences
Australian National University
Canberra, ACT, Australia
(02) 6125 2099
Personal home: www.webone.com.au/~hnksw