EPA Method 507 Surrogate Standard Back Catalog number: 19049 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 72693 Heptanoic acid Price on request 2310.10-100 Chlorotoluron, 100µg/mL, Solvent-c.hexane or ac.nitrile, Unit 1mL, # of units-1, Cas.no. 15545-48-9 Price on request 72462 N,N-Diethylaniline Price on request