Copper content detection in ferric chloride etchant during etching process

Q. I will be very grateful to the person who can give me an idea about how to detect the amount of copper content in a ferric chloride ⇦ on eBay or Amazon [affil link] Solution used for an etching process. Any detection method will be fruitful to my investigation but if someone knows about a colorimetric way or a conductivity method then it will be the apogee. Thanks in advance for any help.

A. I would suggest a titration where you titrate with a standard solution of something that will precipitate the copper out without precipitating out anything else (for example the iron). Then you can follow the titration using a Redox electrode and look for the inflection point. Obviously atomic absorption ⇦ on eBay or Amazon [affil link] and ICP ⇦ on eBay [affil link] work very well but are quite expensive.