I'd say the most correct answer is 'no, its not possible'.

Bitcoins don't exist as independently tracked entities in the system, as such. Lets say an address with 10 unmarked Bitcoins receives 10 marked Bitcoins, such that its balance is now 20 bitcoins.

If it then sends 5 bitcoins to another addresses, it is not possible to make statements about what proportion of those 5 bitcoins were marked - the individual Bitcoins are not individually identified.

So, its more meaningful to think of balances getting transferred around, rather than Bitcoins.

What you can do, is the type of flow analysis we did, where you try and track the majority of flow in and out of addresses, and make inferences about how the Bitcoins flow around. As the network is currently used, this appears to work well - which is one of our main findings - but I'm sure this analysis, as we currently do it, could be frustrated by employing mixing of various types - especially if such mixing were done at a protocol level.

This still has other problems - you are then trusting the mixer to some extent, and I'm sure there are attacks that are possible where someone deploys a malicious mixer, or where someone constantly floods a mixer with coins under their control.