EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended H945928 7-Hydroxy Methotrexate-d3 Ammonium Salt, 1mg Price on request 3517.14-100 Triadimefon, 100µg/mL, Solvent-c.hexane or ac.nitrile, Unit 1mL, # of units-1, Cas.no. 43121-43-3 Price on request MA9061 1,413 µS/cm conductivity solution (230mL) Price on request