Laser Ablation Spectroscopy (LAS) Coupled with ICP-MS and Its Applications in Geoanalysis

Laser ablation spectroscopy (LAS) is an elemental analysis method that requires in principle only optical access to the sample surface and can therefore be used as a real time， in-situ and remote monitoring method，with the advantages of the high space resolution，the speed of analysis，the ease or absence of sample preparation，the relatively low cost，and the possibility to build portable instruments that allow real field analysis for any substances (gas，liquid or solid). However，major restrictions are the poorer detection capabilities for trace elements compared to Inductively Coupled Plasma Mass Spectrometry (ICP-MS). ICP-MS is a powerful，high sensitivity and low limit tool for multi-elemental and isotopic analysis. But the sample preparation consumes time and the matrix elements influence the analysis results. Combine LAS with ICP-MS to form LAS and LA-ICP-MS can complement the weaknesses of these two techniques. For example，LAS can be used first to filter the samples of high contents to decrease the aggradation of the elements on the skimmer core and reduce the matrix effects，and to test the homogeneity of the samples and the stability of the laser，so that to improve the accuracy and precision of the analysis. The LA-ICP-MS has a separated laser sampling device，which makes it flexible to optimize the parameters of atomization and ionization respectively to improve the analysis performance. LAS-ICP-MS has been employed on the analysis of rocks and minerals，which shows good application prospects.