EPA Method 500 Series Internal Std #4 Back Catalog number: 30003 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 673757 Carbofuran, 100 µg/ml, Ethyl acetate, 5ml Price on request A10240400AL-100 Amlodipine, 100µg/mL in Acetonitrile. 1ml Price on request 673705 Tetradifon, 10.0 µg/ml, Ethyl acetate, 10ml Price on request