Laser ablation assisted spark induced breakdown spectroscopy on soil samples

Abstract

Laser ablation-spark induced breakdown spectroscopy (LA-SIBS), characterized by a developed high voltage fast pulse discharge spark, allows direct in-site analysis of non-conductive material without prior sample preparation. Currently laser induced breakdown spectroscopy (LIBS) permits qualitative analysis of a solid or liquid sample by ablating a tiny portion of it, then analyzing the resulting plasma. The LA-SIBS takes this a step further by employing a specifically designed high voltage and fast pulse discharge circuit to enhance plasma emission produced by laser ablation. In this article, LA-SIBS was used for optical emission spectroscopy of soil and compared with a single pulse (SP) LIBS technique. Except for great signal enhancement of plasma emission, the precision in terms of relative standard deviation (RSD) was generally improved by about 2 to 3 times. In addition, the signal to noise (S/N) ratio was improved by about 2 to 3 times as well. These characteristics will thereby probably benefit sensitivity for minor element analysis in most potential analytes. The signal enhancement with improved precision and S/N ratio on soil samples by LA-SIBS was demonstrated.