Laser Ablation ICP-MS

Laser ablation ICP-MS is a technique used for direct analysis of solid samples and is widely becoming a technique commonly used to measure trace elements in marine calcifiers.

At UC-Davis, I helped develop the lab protocol for analyzing foraminifera and have worked with students and other researchers on analyzing trace elements in oysters, otoliths, speleothems, mussels, olivella shells, and tree cores.

Below is an example of a laser ablation depth profile of a foram I analyzed using the LA-ICP-MS system at UCD. This is an amazing technique for understanding how growth conditions affect shell geochemistry. For example, in the specimen below the foraminifer was grown in seawater with elevated Ba/Ca ratios (4x ambient) during the day and ambient seawater at night. By using a low repetition rate and low energy density we are even able to resolve thin inner calcite banding. These inner calcite Mg bands occur across a few microns of calcite. This shell was analyzed as part of a culture study where we modified light conditions to assess controls on the Mg/Ca banding in this species.

Select projects:

• Field research with living foraminifera: for proxy development and biomineralization research
• Laser-ablation ICP-MS for analyzing trace elements in forams
  
• Reconstructing upper water column hydrography using multiple species of planktic foraminifera
• Electron microprobe image maps of the Mg/Ca ratio in G. ruber and N. dutertrei (PhD research)
• Carbonate ion concentration in the ocean (proxy development, PhD research)