Inductively coupled plasma emission spectrometry of solid samples by laser ablation

Abstract

A laser-inductively coupled plasma (ICP) system for the direct analysis of solid samples was constructed by combining a Q-switched or normal laser and an ICP apparatus. Metal samples such as steel, brass, aluminum alloy, and titanium-base alloy were used as solid samples. The sample was set up in a laser ablation cell, and the sample surface was shot by laser beam. The sample vapor produced from the surface by laser shot was introduced into the ICP by the flow of argon carrier gas. The emission signals of various elements were measured with a multichannel analyzer. For the Q-switched laser, the distance between the laser ablation cell and the ICP torch should be kept as short as possible. For the normal laser, the laser focusing was an important factor. Precision (relative standard deviation) was about 3–10% with the Q-switched laser and about 3–11% with the normal laser. The analytical curves for several elements were linear over two or three orders of magnitude in concentration units. As to the detection limit expressed in concentration, the values for various elements obtained by the normal laser were lower than those obtained by the Q-switched laser.