Three-dimensional high-precision mineral mapping using confocal controlled LIBS microscope

Abstract

Laser induced breakdown spectroscopy (LIBS) termed an effective technique to confirm the elemental composition of geologic, due to its unique elemental ‘fingerprint’ properties and qualitative or quantitative analytical performance. However, the low focusing accuracy and poor spatial resolution of traditional LIBS technology limits its application in minerals with complex topography. To address this issue, we constructed a confocal controlled LIBS (CCLIBS) microscope for three-dimensional elemental mapping of natural minerals. The CCLIBS system is an innovative fusion of confocal microscopy and LIBS technology, which significantly improves the spatial resolution and the stability of LIBS spectrum. With this system, the geometry and elemental distribution of natural agate ores are accurately obtained. Then, a common chemometric method of principal component analysis (PCA) was conducted to analyse the differences in such spectral lines. According to the differences of wavelength and intensity characteristics, the typical spectra were selected to map the elemental distribution. Finally, the three elements with the highest PC scores were selected to construct the multi-element fusion mapping, which can reflect the distribution of elements more intuitively. In this paper, we innovatively integrate three-dimensional (3D) morphology with multi-element distribution to characterize the spatial distribution of elements. Compared with single-element fusion, multi-element fusion is more intuitive and clearer, which is of great significance for the analysis of complex components of natural minerals. To solve the problems of low focusing accuracy and poor spatial resolution of traditional LIBS technology, we constructed a confocal controlled LIBS microscope for three-dimensional elemental mapping of natural minerals. The microscope is an innovative fusion of confocal microscopy and LIBS technology, which significantly improves the spatial resolution and stability of spectrum, ensuring that the system can achieve minimal ablation at focal point. Furthermore, we integrate three-dimensional (3D) morphology with multi-element distribution to characterize the spatial distribution of elements. The innovative method provides an effective way for elemental characterization in the fields of biomedicine, materials science and geological science.