EPA Method 8121 Internal Standard Back Catalog number: 81203 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 1581.2-100MG Dicyanodiamide (Cyanoguanidine), neat, Solvent-neat, Unit 100mg, # of units-1, Cas.no. 461-58-5 Price on request 673187 Aclonifen, 100 µg/ml, Acetonitrile, 5ml Price on request 57381 Thallium (Tl) Price on request