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Electrospray Mass Spectrometry

Applying a common biochemical assessment tool to environmental analyses, researchers have come up with a technology that should speed DOE's remediation work while cutting costs.

The technology is electrospray mass spectrometry (EMS), which creates gas phase ions from a liquid sample for mass spectrometry. While EMS is widely used for identifying biological molecules in pharmaceutical analysis, biochemical research and other medical applications, Ames Lab scientists believe it should be applied to environmental assessment as well.

"We think EMS may allow us to get more information on the chemical forms of contaminants," says Sam Houk, principal investigator of Ames Lab research to develop EMS for environmental analyses. "This is important because chemical speciation affects the toxicity of many elements, as one form can be poisonous and another form completely innocuous," he explains.

Seeking even more analytical ability from one technology, the researchers are also combining EMS with capillary electrophoresis (CE), a technique that uses an electrically charged capillary to separate elements. The new combination should allow identification of isobars, elements with the same atomic weight that usually cannot be distinguished by mass spectrometry. It should also allow quick characterization of the overall composition (i.e., cations, anions, chelating agents, etc.) of a complex waste solution.

Building upon the advantages conventional mass spectrometry already brings to environmental assessment (sensitive and rapid multi-element analysis), the new CE-EMS combination should offer more comprehensive analysis than is typically available in one cost-effective, convenient instrument. Plans include incorporating the new system into a mobile laboratory for field demonstrations at other DOE sites. The work is a collaborative effort with Perkin-Elmer, a world leader in scientific measurement equipment, and Sciex, a Canadian company that developed and manufactures EMS.


  • Conveniently Comprehensive - The new electrospray mass spectrometry system should identify trace elements, radionuclides and isobars (usually not identifiable by mass spectrometry) with a single instrument, offering more convenient and cost-effective analysis.
  • Provides Additional Chemical Information - EMS can also provide details on the chemical structure of contaminants that should allow important insight into their toxicity, a capability not easily available with other instruments.
  • Increased Portability - EMS does not require large gas supplies, allowing easier portability for on-site analysis.
  • Small Samples - EMS needs samples of only one microliter or less, reducing the amount of contamination to be handled and then disposed of.


Adapting for environmental use an analytical technology already common in medical applications, researchers are developing a single instrument comprehensive enough for a wide range of environmental analyses. Reducing the need for multiple analytical tools, this system should cut the costs and complexity of DOE's environmental assessments.


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