EPA Method 509 Internal Standard Back Catalog number: 30097 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 679463 Endrin, 100 µg/ml, Methanol, 1ml Price on request 675902 Propylene thiourea, 250mg Price on request 678151 Terbufos-sulfoxide, 100 µg/ml, Acetonitrile, 1ml Price on request