Laser-Spark Excitation of Homogeneous Powdered Materials

Abstract
The laser microprobe has been applied to the excitation of trace elements homogeneously distributed in powdered materials. Precision of intensity ratios is about ±11% (coefficient of variation), and detection levels are comparable to those of the dc arc. Matrix effects were studied for four different materials and found to be significantly less than in the dc arc. Use of the probe as the source in a “universal” method is suggested.