EPA Method 500 Series Internal Standard Back Catalog number: 31004 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 2189.4-50-ME Perfluorobutyric acid, sodium salt, 50µg/mL, Solvent-methanol, Unit 1mL, # of units-1, Cas.no. 2218-54-4 Price on request M338687-5MG Metoclopramide-d3, 5mg Price on request 10656.15-25-MX U-(13C15)-Nivalenol Price on request