Investigation of resonance excitation of trace elements using resonant laser-induced breakdown spectroscopy (RLIBS)

As a micro-damage detection technique, laser-induced breakdown spectroscopy (LIBS) is often applied in various fields. However, LIBS analysis often uses high-energy ablation, which inevitably leads to sample destruction. Resonant LIBS (RLIBS), as an improved LIBS, is expected to be used for minimally destructive elemental analysis. In this work, taking the elements of lead (Pb), indium (In), and silicon (Si) as examples, four different excitation modes of RLIBS are investigated. RLIBS with ground-state atom excitation (RLIBS-G) is compared with three resonant excitation modes, namely RLIBS with excited-state atom excitation (RLIBS-E), RLIBS with normal stepwise-line atom excitation (RLIBS-NSL) and RLIBS with thermally assisted stepwise-line atom excitation (RLIBS-TASL). The results show that RLIBS-G achieves better spectral intensity. Furthermore, we compare the quantitative analysis results of Pb in copper alloys using RLIBS-G and typical LIBS. The results demonstrate that RLIBS-G achieves better detection sensitivity and accuracy. The limit of detection (LoD) of 10 mg kg(-1) is obtained using RLIBS-G. This work indicates that RLIBS is a promising approach for determining trace elements in micro-damage detection analysis.