diets were supplemented with anhydrous cupric sulfate to yield the following copper concentrations ( ppm , by analysis ) when the three experiments were combined : 0.6 , 0.9 , 1.3 , 1.9 , 2.0 , 2.8 , 3.2 , 4.0 , 4.9 , 5.6 and 9.3 .
C0056301
anhydrous cupric sulfate
C0009968
copper