EPA Method 551.1 Internal Standard Back Catalog number: 32103 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 20227 CLP Pesticide Standard Price on request 682369 Tolpyralate, 100 µg/ml, Acetonitrile, 1ml Price on request 10763.6 Hexanal-13C4 Price on request