Laser–induced breakdown spectroscopy combined with surface coating to enhance emission line intensity of metallic elements in metal sheet

Emission intensity plays an important role in laser–induced breakdown spectroscopy. A new sample preparation method is proposed to enhance the emission intensity for determining metallic elements. A layer of epoxy resin film is cured on the surface of a metal sheet sample, and a laser beam is used to ablate the film and form a circular hole through it. Results show that by using the proposed method, the emission intensity for Al, Cr, Cu, Fe and W increases by 66.7%–699.6%, and the relative standard deviation (RSD) decreases from 6.5%–25.5% to 0.2%–12.9%. This suggests that emission lines with high intensity and low RSD can be obtained using the proposed method. This convenient and low–cost method has the potential for improving the quantification and imaging performance of bulk samples.