Crater formation and signal intensity in nano- and femto-second laser ablation inductively coupled plasma mass spectrometry

Inductively coupled plasma-mass spectrometry (ICP-MS) is a widely used analytical technique and produces highly accurate results. One of the main disadvantages of the technique, however, is the necessity of solid sample preparation into a solution; this is remedied by the use of laser ablation (LA) for direct solid sampling. LA is the process of delivering energy to a sample via a laser and, consequently, removing part of the sample and forming a small crater on the surface of the sample. Currently there exist several issues in LA sample introduction to ICP-MS commonly called ‘elemental fractionation’. A better understanding of fundamental laser ablation mechanisms and particle generation during LA process are necessary in order to efficiently couple the laser beam into the sample, ablate a reproducible quantity of mass, minimize the plasma shielding and fractionation, and control and optimize ablated particle transport.