LAMCICPMS

LAMCICPMS stands for Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry. It is an analytical technique used for in situ isotopic analyses of solid materials, combining a laser ablation system with a multi-collector ICP-MS to measure isotope ratios with high precision and spatial resolution.

Principle and instrumentation: A pulsed laser ablates a small volume of the sample, producing an aerosol carried by inert gas into a thermal ICP torch where elements are ionized. The multi-collector mass spectrometer simultaneously records signals on multiple detectors corresponding to different masses, enabling accurate isotope ratio measurements and reducing drift. Typical laser spot sizes range from approximately 10 to 100 micrometers, enabling micro-scale mapping of isotopic composition. The system may use nanosecond or femtosecond lasers; carriers are typically argon.

Applications: Widely used in geoscience for Pb, Sr, Nd, and Hf isotope systems in minerals, rocks, and zircon; geochronology and provenance studies; environmental and planetary science; archaeology and art conservation; and materials science. The technique provides spatially resolved isotopic information that complements bulk analyses.

Calibration and data analysis: Requires matrix-matched standards to correct for ablation yield and mass bias; isotopic ratios are reported with uncertainties (often using k=2). Data reduction considers background, dead time, fractionation during ablation and ionization, and transport efficiency. Absolute concentrations may be estimated with external calibration using reference materials.

Advantages and limitations: Advantages include in situ analysis, high spatial resolution, minimal sample preparation, and precise isotope ratio measurements. Limitations involve matrix effects, the need for robust standards, complex data correction, high instrumentation cost, and generally lower absolute concentration sensitivity compared with solution ICP-MS for some elements.