The primary test of quality for zinc oxide is the heavy metal content of the product. Additionally, many of the low quality byproduct zinc oxides contain considerable amounts of aluminum and chlorine. Brown to green. Fortunately, there are substantial zinc deposits in both Canada and Mexico and a large portion of our imported zinc comes from these two friendly neighboring countries. Availability of zinc should be fairly good into the foreseeable future.
Zinc oxide is the major compound used to supply zinc in the feeds of all species of animals.
Wet analysis is preferred for assaying high concentrations. Use Scott's Standard Method of Chemical Analysis.