Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)
LA-ICP-MS is based on focusing a pulsed laser on a sample surface. The laser pulse ablates material from the sample forming an aerosol of particles. Using a specially designed ablation chamber, the generated particles are efficiently washed-out and transported to an ICP-MS instrument using a He gas flow. In the ICP, the ablated particles are vaporized, atomized, and subsequently ionized. The generated ions are transferred to a high vacuum system, and the ion beam is focused. Using a mass analyzer (quadrupole, sector-field, or time-of-flight), the ions are separated by their mass-to-charge ratio and subsequently detected (Figure 1).
LA-ICP-MS provides several characteristics which makes it a unique technique in the field of direct-solid sampling elemental analysis:
- LA-ICP-MS provides outstanding sensitivity with detection limits in the ng/g-µg/g range for most elements.
- LA-ICP-MS can detect almost all elements of the periodic table except: H, He, N, O, F, Ne, Ar
- LA-ICP-MS can provide spatially resolved information with a lateral resolution in the low µm range and a depth resolution of several 100 nm. Therefore, it is an excellent tool for the fast mapping of large sample areas and analysis of layered samples with thicknesses up to several mm.
- LA-ICP-MS provides isotopic information