“…By using a DP-LIBS approach, improvements on signal-to-noise ratio (SNR) [7], signal-to-background ratio (SBR) [8,9] and limits of detection (LOD) [10] have been reported. Overall results in the current literature suggest that mechanisms involving signal enhancement depend on many parameters such as material properties [5], laser pulse energies and power densities [11][12][13], laser pulse wavelengths [11,14,15], interpulse delay times (Δt) [9,[16][17][18] and geometrical configuration [5,6,19]. Despite efforts made to explain the signal enhancement mechanisms, these are not completely clear and optimal experimental conditions are yet to be determined.…”