EPA Method 525 Internals & Surrogates Back Catalog number: 91161 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 97279 Aliphatic Internal Standard Price on request 70193 Heptachlor epoxide (isomer B), 1000µg/ml in MeOH, 1ml Price on request 53359 Al, Fe, B, Ti Mix Price on request