EPA Method 551.1 Internal Standard Back Catalog number: 30103 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 673842 Trinexapac-ethyl, 10.0 µg/ml, Acetonitrile, 10ml Price on request 59747 Metals Mix Price on request 678148 Sulprofos, 100 µg/ml, Acetonitrile, 5ml Price on request