EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 71175 Polyethylene glycol Price on request A12670400AL-100 Dimethachlor OA, 100µg/mL in Acetonitrile, 1ml Price on request 71597 Isoxaben Price on request