I know this is old, but I just happened to see it. Last week we at the ASMS conference's Agilent Users' Meeting were treated to a talk relevant to your question. The speaker was Ashli E. Browne of the Mississippi State Chemical Laboratory, and part of her talk was focused on analyzing chemical residues in the environment resulting from the Deepwater Horizon oil spill.
She mentioned that the lab does a little bit of contract work, so she may be able to help.
Thanks. - Josh