EPA Method 500 Internal Standard #6 Back Catalog number: 30169 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 1582.11-250MG Proguanil hydrochloride, neat, Solvent-neat, Unit 250mg, # of units-1, Cas.no. 637-32-1 Price on request 678260 Amitrole, 100 µg/ml, Acetonitrile, 1ml Price on request 1695.18-100MG 6-n-Heptylnaphthalene-2-carboxylic acid, neat, Solvent-neat, Unit 100mg, # of units-1, Cas.no. 66473-01-6 Price on request