How do I determine the sectors that are occupying a drive track?

I am interested in locating "the last 512 bytes of the first logical drive track" in order to determine if a drive is encrypted with truecrypt according to [their provided specification](http://www.truecrypt.org/docs/?s=volume-format-specification). I would only be running this check when the drive was decrypted, as I would be executing it as an audit remotely for our systems.

Any assistance is appreciated.

Thanks,

Matt