EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 674529 Benzyldimethyltetradecylammonium chloride, 10.0 µg Price on request 1572.36-250MG Dimethyl pseudomorphine, neat, Solvent-neat, Unit 250mg, # of units-1, Cas.no. 121395-47-9 Price on request 79596 Formaldehyde Price on request