Improvements in Inductively Coupled Plasma - Mass Spectrometry


Simpler sampling can reduce the hazards, costs and complexity of site assessment, and that's what's on the way for an established analytical technique.

Scientists are modifying inductively coupled plasma-mass spectrometry (ICP-MS), a technique developed at Ames Laboratory in the 1970s and now commonplace in environmental assessment as the most sensitive and selective tool available for multi-element analysis. To enhance sampling, the new ICP-MS will include a monodisperse dried micro-particulate injector (MDMI) that places samples in an ideal form for analysis.

With MDMI, ICP-MS should need only very small samples, from a nanoliter to a microliter in volume. "This should let us analyze many radioactive samples with little or no containment considerations," says Ames Lab's Sam Houk, an original developer of ICP-MS who is now principal investigator of the MDMI-ICP-MS project.

Traditional sample sizes often require costly and time-consuming containment to prevent the spread of contamination to workers, other solutions or the surrounding site.

"There will also be significantly less contaminated waste to collect and dispose of after an MDMI-ICP-MS analysis, since a smaller sample going in means less coming out when analysis is complete. A smaller sample in the spectrometer provides another advantage: less frequent replacement of contaminated instrument parts. Radioactive materials stick to the ICP-MS sampler cone," Houk explains. That makes it necessary to remove, dispose of and replace the cone at a cost of several hundred dollars each time. That will still happen with MDMI-ICP-MS, but it will be much less of a problem.

While the MDMI is not yet available commercially, there is interest. In fact, the researchers are working with an advance prototype of the device from Perkin-Elmer Sciex, a joint venture of two world leaders in analytical instrumentation.



  • Safer Sampling - Smaller samples pose less risk to workers and minimize the spread of contamination.
  • Less Secondary Waste - Reduced sample sizes significantly cut the amount of contaminants needing costly and time-consuming collection and then disposal after analysis.
  • Saves Time and Money - Quicker, less complex sampling with minimal containment and secondary waste concerns reduces time and expense of analysis.
  • Augments Established Technique - Modifying the already effective ICP-MS brings new cost and simplicity advantages to this conventional technique established for rapid, sensitive and selective analysis.


Augmenting an already effective analytical technique, Ames Lab's sampling improvements for ICP-MS promise reduced hazards, costs and complexity for assessing DOE's radioactive sites.


Sam Houk, e-mail:, phone: 515-294-9462