The coordination environment of copper in hair can be altered by treatment products.

Abstract

To determine whether the coordination environment of copper in hair is affected by the shampoo used. Electron paramagnetic resonance (EPR) spectroscopy to discriminate between mixed oxygen/nitrogen and mixed oxygen/sulphur coordination of copper after treatment with two different shampoos. Copper with mixed oxygen/nitrogen coordination could be converted to mixed oxygen/sulphur coordination by treating with the appropriate shampoo, but this was not reversible with the products tested, although copper was removed from hair at very high pH values. Commercial hair treatment products can have a profound effect on the copper coordination environment in hair, and this must be taken into account in any attempt to use hair as a health marker.