Indirect laser-induced breakdown of transparent thin gel layer for sensitive trace element detection

Optical emissions from major and trace elements embodied in a transparent gel prepared from cooking oil were detected when the gel was spread in thin film on a metallic substrate and a plasma was induced on the substrate surface using nanosecond infrared pulsed laser. Such emissions are due to indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. Temperature higher than 15 000K determined in the plasma allows considering sensitive detection of trace elements in liquids, gels, biological samples, or thin films. (C) 2013 AIP Publishing LLC.