EPA Method 502/524 Surrogate Standard #1 Back Catalog number: 30070 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 79628 Theophylline Price on request 673881 Paraoxon-ethyl, 10 µg/ml, Cyclohexane, 10ml Price on request 680373 Ethylene thiourea, 100 µg/ml, Acetonitrile, 1ml Price on request