The method of concentrating and preparing the solution for colorimetric assay is as follows.
The further details are on the well-known lines of colorimetric estimations.
When copper is in too small a quantity to be weighed, it may then be estimated by a colorimetric process.
It is not so delicate as most other colorimetric methods, but nevertheless is a very useful one.
The manner of working this assay is the same as that adopted in the other colorimetric processes.