Copper - 20 PPM Back Catalog number: 50594 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 675243 Paraoxon-ethyl, 100 µg/ml, Acetonitrile, 5ml Price on request 66157 2,3,3’,4,4’,5’-Hexachlorobiphenyl (157) Price on request 59516 Hexavalent Chromium (Cr 6+) Price on request