Comprehensive analysis of elemental distribution in human skin using laser ablation inductively coupled plasma mass spectrometry

Background: Multiple chemical elements play roles in skin homeostasis. The distribution of elements in skin has been studied by X-ray microanalysis methods and fluorescence microscopy using chemical indicators, but the former requires complicated sample preparation steps, while the latter is limited by the availability of suitable chemical indicators. Materials and methods: We applied laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to measure the distributions of thirty-eight elements in human skin. Results: Among the target elements, nine (calcium: ⁴⁰Ca, ⁴⁴Ca, zinc: ⁶⁴Zn, ⁶⁶Zn, phosphorus: ³¹P, potassium: ³⁹K, sodium: ²³Na, sulfur: ³⁴S, copper: ⁶³Cu, magnesium: ²⁴Mg, and iron: ⁵⁶Fe) showed distribution patterns that were consistent with previous reports, and four others (iodine: ¹²⁷I, barium: ¹³⁸Ba, strontium: ⁸⁸Sr, and molybdenum: ⁹⁵Mo) were detected for the first time in human skin. Conclusion: The method described here requires only slicing into sections to prepare a sample for measurement, so the elemental distributions are minimally disturbed, and comprehensive information can be obtained rapidly. The method is expected to be useful for research in a variety of fields, including skin diseases, aging, and allergenicity.