The life of a scientist isn’t all lasers and plasma… until it is. Today’s mundane schedule was punctuated by a visit to my doctoral committee member’s Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA ICP-MS) laboratory of my doctoral committee member for trace and rare earth element analysis of coral samples. For those curious about the intimidatingly named technology, the system works something like this:

A sample is ‘ablated’ (read: vaporized) with a high-powered laser in an evacuated chamber,

The chamber is flooded with helium, and the newly aerosolized material is carried in an argon plasma (which is roughly as hot as the surface of the sun)

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The argon plasma ionizes the material, which then travel through a quadrupole (read: a system of magnetic fields designed to separate isotopes based on their mass to electric charge ratio),

The quadrupole filters the isotopes in the sample so that they collide with specific collectors, which count each collision as sample is run through the LA ICP-MS.

 

 

The result? Counts of certain isotope(s) based on their mass and charge in your sample, which are normally converted into concentrations or ratios with a matrix element (e.g., Ca in carbonates). What makes that information valuable to scientists? Simple; physical processes in the environment result in variation in the isotopic and elemental composition of natural materials such as the calcite in stalagmites that grow in a cave, and skeletons of coral heads that grow near the ocean surface. Measuring certain elements and isotopes in materials such as these can provide a time series of chemical changes through time, which we can then tie back to the geophysical processes that caused these elemental and isotopic ‘fractionations’ when that material was first deposited.