24.0: Thursday, March 17, 2005

LIBS Analysis of Chemical Composition of Skin

Navinderdeep S. Nijher, MD and Lloyd Hoffman, MD.

PURPOSE: The evaluation of the chemical composition of biological tissues at the elemental level presents numerous possibilities for clinical evaluation. Laser Induced Breakdown Spectroscopy (LIBS) is a real time elemental analysis technique that provides such data about the chemical composition of a specimen. We proposed using this difference in elemental composition to help distinguish between different layers of the skin. METHODS: Samples of excess skin normally discarded during procedures such as rhytidectomy or abdominoplasty were harvested and sent for analysis using the LIBS technique. The specimens were treated with multiple laser pulses and the concentrations of various elements were calculated by using the LIBS spectrum analysis. RESULTS: LIBS analysis revealed a thin metal-rich layer that exists on the dermal surface of the skin. This layer corresponded to the epidermis when evaluated by histological section. Furthermore, it was also seen that there appears to be a phosphorus gradient in the skin with a diminishing phosphorus signal as the laser penetrated deeper into the skin. The histological correlation of this gradient is still being refined. CONCLUSIONS: LIBS analysis provides a new means of real-time chemical analysis that we have used to differentiate between epidermis and dermis using objective data.