Research On Libs Quantitative Analysis Of Heavy Metal Concentration In Polluted Water-Based On Fourier Self-Deconvolution Method

Laser-induced breakdown spectroscopy (LIBS)is a real-time and rapid analysis method, which can realize quantitative analysis of element concentration in solid, liquid or gaseous samples. In this paper, a micro-LIBS system was designed for the quantitative analysis of heavy metals concentration in polluted water. The composition of the elements in the polluted water is abundant. Therefore, the characteristic spectral lines of heavy metal elements in polluted water are easy to be overlapped with adjacent characteristic spectral lines due to the spectral line broadening. This paper introduces the Fourier self-deconvolution (FSD) method to solve the problem of characteristic spectral overlap in LIBS quantitative analysis of heavy metals in polluted water. Fourier self-deconvolution (FSD) can decrease the spectral linewidth by taking deconvolution on the spectral using the shape information of the spectral itself. By combining the FSD with other methods such as baseline removal, wavelet domain denoising, spectral normalization and outlier discarding, the LIBS detection limit of Pb concentration in polluted water can reach 79.66 ppm.