Method 1664, Revision A: N-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated N-Hexane Extractable Material (SGT-HEM; Non-polar Material by Extraction and Gravimetry. February 1999. (NTIS / PB99- 121949 or http://www.epa.gov/waterscience/methods/16640514.pdf (PDF, ...
US EPA Method 1613, 1994. Revision B, Tetra- Through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS. Washington, DC.US EPA Method 3630c: Silica Gel Cleanup, in: Test Meth- ods for Evaluating Solid Waste, Physical/Chemical Meth- ods; Third Edition; Final Update 3-A, ...