Analysis of lignite using laser-induced breakdown spectroscopy

The application of laser-induced breakdown spectroscopy (LIBS) to the chemi cal analysis of low-ash lignite has been investigated. A Nd:YAG laser (lamb da = 1064 nm) is used to induce emission from the ash-forming components, w hich is then spectrally resolved and analyzed. LIBS analyses of five inorga nic components of lignite were shown to be reproducible between sample pell ets at a 95% confidence level. Detection limits (in ppm) on an as-received basis of 60 (Ca and Al), 70 (Na), 90 (Fe), and 200 (Mg and Si) were obtaine d from a study of 30 lignite samples, each of which was interrogated by 300 laser pulses.