Determination of Lead and Copper in Ligusticum wallichii by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy was used for the analysis of the Chinese traditional medicine, Ligusticum wallichii. The laser energy and delay time were optimized to obtain best spectral quality. The limits of detection for lead and copper were 15.7 and 6.3 mu gg(-1), respectively. Multiple linear regression models between the laser-induced breakdown spectroscopy intensity and the mass fraction of lead and copper were constructed. Good agreement was observed between the actual concentrations and predicted values obtained by the models. These results demonstrate that the laser-induced breakdown spectroscopy coupled with multiple linear regression is suitable for the determination of heavy metals in Chinese traditional medicine.