Characterization of the Chinese Traditional Medicine Artemisia annua by Laser-Induced Breakdown Spectroscopy (LIBS) with 532 nm and 1064 nm Excitation.

In order to investigate the influence of laser wavelength on the detection of the metals in Artemisia annua, pulsed lasers operating at wavelengths of 1064 nm and 532 nm for laser induced breakdown spectroscopy (LIBS) have been employed to generate the plasma. The spectral lines of Mg (II) at 279.54 nm, CN at 388.29 nm, Ca (II) at 393.37 nm and Fe (II) at 404.27 nm were used to evaluate the optical emission at various delay times for the 532 nm and the 1064 nm laser. The effects of the data acquisition delay time on the line intensity, signal-to-background ratio and the characteristic parameters of laser plasma have been investigated as well. The results show that the 1064 nm beam induced plasmas with higher signal-to-background ratios and temperatures than the 532 nm beam. However, the 532 nm laser beam produced plasma with higher electron densities than the 1064 nm laser beam. In addition, a significant influence has been found: the spectral intensities of the ions were stronger than the spectral intensities of the atoms independent of whether the laser was operated at 532 nm or 1064 nm. [ABSTRACT FROM AUTHOR]