Your first approach is more straight-forward and will be easy to carry out. Moreover, it may turn out to be more accurate and LOD at a lower concentration. The back titration approach can also be helpful but is tricky in titration and calculations. Since you are digesting copper and running your EDTA based titration, it may be more accurate. These methods involving digestive approaches have turned out to be more accurate given that your handling at each stage is very careful with no loss of the mass and reactions are complete.

As a quick follow-up, what level of Cu do you expect from the powder?  The success of the titrations depend on the amount of Cu.  I know you want titration, but do you have access to Atomic Absorption or ICP?  They will give you good results at low levels.

The copper content is relatively high; 1-20%. Neither Atomic Absorption nor ICP are viable options as the method needs to be simple - because it is intended that the method will be used by customers who will have access to basic equipment only. We plan to use more sophisticated methods/equipment to verify the results obtained with the simple method but they cannot be part of the simple method.

Hi Paddy,

Copper Analysis by Complexometric Titration is more straightforward.

Cheers,

Ramin

Iodometric titration of copper is a simple and low cost method to determine copper content. If you google the topic you will find many easy procedures employing chemicals you probably have in your laboratory.