LASER MICROANALYSIS OF GEOLOGICAL SAMPLES BY ATOMIC EMISSION-SPECTROMETRY (LM-AES) AND INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY (LM-ICP-AES)

Recent advances in laser microanalysis techniques and their application to selected geochemical case studies are presented: (1) A single-step method is described for determining the distribution of major and minor elements in ferromanganese concretions by laser microvaporization-atomic emission spectrometry (LM-AES). Some results of the distribution of Ba, Fe and Mn and their linear correlation are discussed. The detection of periodicities in a line scan in the presence of noise is made possible by means of auto-correlation and cross-correlation techniques. (2) A two-step method is presented for determining the bulk content of La in pseudobrookite by laser microvaporization-inductively coupled plasma-atomic emission spectrometry (LM-ICP-AES). Calibration is undertaken with liquid standards using Ti as an internal standard. Good precision and accuracy have been achieved using this method.