EPA Method 525.2 Standard Back Catalog number: 92693 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 68C-IS Labelled Injection/Internal Standard Stock Solution, 1.2ml, nonane Price on request 677013 1-Isopropyl-3-phenylurea, 25mg Price on request 54256 Ammonium (NH4+) Price on request