Study on enrichment characteristics of Chinese herbal medicine based on LIBS technology

To improve the accuracy of laser induced breakdown spectroscopy(LIBS) measurement and investigate the enrichment characteristics of trace elements in different parts of Chinese herbal medicine, the original spectral data of different Chinese herbal medicines were preprocessed by combining median absolute deviation(MAD), segmented feature extraction, and wavelet denoising, and the enrichment laws of trace elements in different parts of Chinese herbal medicine were studied based on the calibration free laser induced breakdown spectroscopy(CF-LIBS). For these experimental samples, the contents of K, Ca, Mg, and Fe in chrysanthemum and its roots, stems, and leaves, Iris lactea roots and leaves, Salvia miltiorrhiza and corresponding planting soil were obtained by CF-LIBS. By calculating the element enrichment coefficient, it was found that chrysanthemum had strong enrichment ability of K element, and the enrichment ability of K element was flower > leaf > stem > root. The roots and leaves of Iris lactea showed strong enrichment of Ca and Mg. The enrichment ability for Ca is leaf > root, and for Mg is leaf > root. The enrichment coefficient of Ca and Mg in Salvia miltiorrhiza is higher. The results show that the combination of multiple data preprocessing methods can effectively improve the accuracy of LIBS measurement results. The calculation method of trace element enrichment law in different parts of Chinese herbal medicines provides guidance for the cultivation and fertilization of Chinese herbal medicines and the identification of high-quality Chinese herbal medicines.