Laser spectroscopic investigation of the stability of coated titanium microparticles used in sunscreens

The method of laser induced plasma spectroscopy was used for the analysis o f the mechanical stability of coated titanium dioxide microparticles used i n commercial sunscreens without additional preparation. No changes in the m echanical stability of the coating material could be detected during the ma nufacturing and penetration process. Only after centrifugation of the sampl es changes in the ratio of the titanium/aluminum fluorescence intensity cha racterizing the stability, were clearly detected. These conditions are not typical for sunscreen manufacturing or application. The detection of small coating damages by laser induced plasma spectroscopy demonstrates that the used method is suitable for the analysis of the mechanical stability of the coating layer of microparticles.