In a thread on researchgate, the concern was raised that long term exposure to unbuffered preservation fluids such as ethanol or formaldehyde may leach heavy metals from biological samples due to a reduction in the fluid's pH. Can anybody tell me if this also applies to mollusc samples? I would assume that carbonate shells function as a pH buffer and thus keep the fluid's pH relatively stable over a long time.
Edit: Link to the researchgate thread. No research articles were mentioned in that thread.