Case Study: Trace Copper Contamination In a Coffee Cup

The Problem:   The reported metallic taste of the water and a trace amount of blue deposit in a coffee cup caused concern to the office worker who owned it.

The Answer:     LIBS analysis identified the material as a copper silicate, possibly originating from plumbing work recently carried out in the building.

Spectrum of blue deposit (about the size of a grain of salt) recovered from a stained coffee cup, showing copper silicate contamination: