Quadrupole ICP-MS Laboratory - Laser Ablation Job Info Form

LA-ICP-MS is a versatile analytical technique to derive spatial compositional information from surfaces of solid samples. Typically spots or line scans are performed for this purpose. The laser essentially acts as a high precision photon "jack hammer" that generates a fine particulate aerosol, which is carried to the torch and sample introduction system of the ICP-MS. The laser control parameters for generating optimal aerosols can vary substantially depending on the material. Optimal laser energy for ablation is concentrated over a narrow focal range, thus samples appropriate for LA-ICP-MS should present a flat uniform surface. Thin sections and polished slabs work very well and the laser ablation cells are designed to accommodate such samples.

USE THIS FORM TO SUBMIT SAMPLES FOR LA-ICP-MS PROJECTS
(e.g., Samples are melt inclusions in Rhyolite. We wish to determine alkaline earth and REE concentrations.)
(Samples not picked up within 3 months of analysis will be destroyed)

Sample Considerations

 
Analytical surfaces of samples must be in the same horizontal plane, which necessarily corresponds to the top of the laser ablation chamber drawer. Samples of highly variable thickness (≥ several mm) can be differentially raised to this plane by various means, but consistent sample thicknesses of a few mm to 1 cm are easiest to work with. Standard 30 µm-thick thin sections typically offer sufficient depth for LA analyses, but thicker samples (e.g., 100 µm) are required for some applications. Please contact the lab for specific information about sample size requirements for our ablation cells.

Analytical surfaces of samples should be as clean as possible before analysis. Although sample surfaces can be "cleaned" by pre-ablation, highly porous samples may still contain sample preparation-related contaminants (e.g., polishing grit, carbon or Au/Pd coating). Pre-ablation is typically very effective for "cleaning" non-porous sample surfaces.

Quantitative determination of cation concentrations by laser ablation ICP-MS (LA-ICP-MS) requires: (1) an appropriate internal standard element, an analyte that has a known constant concentration (typically determined from EPMA or assumed from mineral stochiometry; e.g., calcite is 40.0432 wt% Ca); and (2) an appropriate laser ablation standard(s) of known composition that includes the internal standard element and also has analyte concentrations reasonably close (ideally within the same order of magnitude) to those in the unknown. Spot analyses are best for stationary compositional measurements, whereas line scans can provide continuous lateral compositional information.

For more information about considerations for LA-ICP-MS projects, please visit: http://www.jsg.utexas.edu/icp-ms/laser
 
(e.g., standard 30µm thin sections, carbon-coated 1" round for EPMA, polished rock slab)
(e.g., Samples are clinopyroxene and orthopyroxene)

Lab-Affiliated Publications: http://www.jsg.utexas.edu/icp-ms/publications/

 
Knowing how the lab serves your research needs is important and helpful information. Please help us keep your publications up-to-date by responding to the three questions below. Your help with this is greatly appreciated!!!
 


(e.g., Gardner J.E., Befus, K.S., Watkins, J., Hesse, M. and Miller, N., 2012. Compositional gradients surrounding spherulites in obsidian and their relationship to cooling and spherulite growth. Bull. Volcanology 74, 1865-1879.)

Costs & Payment Method

 
Analytical costs for laser ablation ICP-MS are charged on an hourly basis.  Hourly charges may also apply for sample preparation, experiment set-up, method development, post-processing of data, and user training. Collaborative projects* are charged at 75% and are expected to include co-authorship on derivative publications. Savings may be available for analyses run outside of business hours by qualified users (http://www.jsg.utexas.edu/icp-ms/courses/).

Laser Ablation ICP-MS User GroupHourly cost $
Internal academic collaborative (JSG/UT)53.75
Internal academic (JSG/UT)73.00
External academic collaborative (non-UT)69.75
External academic (non-UT)93.00
Commercial collaborative185.29
Commercial247.05
 
*Remittance instructions will be provided with the invoice; **Bank information will be provided with the invoice. Any transfer charges from the originating institution/bank should be added to the invoiced amount.

Acknowledgement