Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is an analytical technique that can obtain precise major, trace element and isotopic information directly from solid phases, thus preserving spatial context; typically sampling a volume ~10-100 µm in diameter and >1 µm in depth. This technique is particularly useful for making spatially resolved measurements of (1) trace element abundance patterns & isotope ratios for fingerprinting different geologic sources and processes, (2) accurate estimates of crystal/melt partition coefficients, and (3) detailed characterization of diffusion profiles. A pulsed focused laser beam removes material from the sample, and the resulting aerosol is transported into the Inductively Coupled Plasma Mass Spectrometer (ICP-MS) for ionization and detection.

LA-ICP-MS analyses are performed using a Teledyne Photon Machines Analyte Excite+ laser ablation system coupled to the Element XR ICP-MS within the ICP-MS Laboratory. The laser ablation system uses an excimer laser with a 193 nm wavelength for optimal ablation characteristics in a wide range of geological phases. The spot size can be varied from 1 to 250 µm to allow for fine- to coarse-scale analysis of phases by LA-ICP-MS. The pulse length is <4 ns and allows for depth profiling at <50 nm per shot depending on material. The maximum repetition rate is 300 Hz, with energy density from 1 to 15 J cm-2. The LA-ICP-MS system is also equipped with a fast washout system (ARIS) for mapping of trace element distributions in samples.

Center for Isotope Cosmochemistry and Geochronology (CICG)

Center for Isotope Cosmochemistry and Geochronology (CICG)

Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS)