Oil Sample Analysis, Houston Area

Does anyone know of a private lab that can do oil sample analysis, preferbaly in the Houston area? This is related to a possible oil pollution incident, not standard engine maintenance or oil quality analysis. Any contacts for this would be greatly appreciated.

Inspectorate would be one. http://www.inspectorate.com/oil_and_petrochemicals/testing.asp
Intertek/Caleb Brett would be another one: http://www.intertek-cb.com/