Why could the granules in a Lachat cadmium column turn copper colored?
Copper colored cadmium column granules
The granules in a Lachat cadmium column (Product # 50237A) could turn copper colored if too much copper sulfate is added to the buffer. Hach recommends adding two drops of 20 g/L copper sulfate to one liter of buffer to increase the life of the column. If too much is accidentally added, the granules can become copperized and turn color. Below is an example of what this may look like: