Metal powder-assisted laser induced breakdown spectroscopy (LIBS) using pulse CO2 laser for liquid analysis

Analysis of impurity and trace element in liquid is urgently needed in environment and industries. In this present work, new sampling technique of laser induced breakdown spectroscopy (LIBS) has been devised using metal coarse utilizing pulse CO2 laser. Experimentally, a liquid and polluted liquid was dropped into a metal coarse powder. A pulse CO2 laser (10.6 µm, 200 ns) beam with a laser energy from 0.75 to 1.5 J was bombarded on a metal coarse to induce a plasma. The plasma contains elemental analytical lines obtained from the liquid material; the metal coarse itself is never ablated and only works to induce a plasma. By this present technique, identification of major and minor elements in liquid material target such as commercial milk liquid and multi-vitamin liquid has successfully be made. Furthermore, a quantitative analysis of impurity of Cr has been demonstrated, resulting in good precision and good sensitivity with limit of detection of approximately 2 µg/ml. This present developed technique is possible to be employed for analysis of major, impurity, and trace elements in liquid and water without any tedious sample pretreatment.