How to identify absorption in a subdiffusive medium

We consider subdiffusion in a system which consists of two different media separated by a thin membrane. In one of the media particles' absorption can occur. Such systems can be studied experimentally but, due to technical reasons, it is not always possible to measure concentration profiles in the medium in which absorption can be present. We show the method which allows one to recognize whether absorption is present in such a medium knowing concentration profiles of diffusing substance in the other medium.