By testing an ice-core from Summit Station, Greenland, researchers at the U.S. Army Engineer Research and Development Center’s Cold Regions Research and Engineering Laboratory (CRREL) have evaluated laser-induced breakdown spectroscopy (LIBS) to assess its suitability as a real-time detector of paleo-climate proxy indicators. This study characterized the bulk ice and, for the first time, individual dust particles in the ice. The test demonstrated the potential for LIBS to eliminate the need for cold-room storage by removing the logistical need for transport of ice-cores out of the field. The ultimate goal is to develop a field-portable LIBS capable of operating in austere environments.
A Leap-ahead Technology for Analytical Analysis
The benefits of LIBS include fast, real-time and in-field analysis with stand-off capabilities and minimal sample preparation, no hazardous waste generation, lower instrument capital cost, and lower operation and maintenance costs. This leap-ahead technology is capable of multi-element and isotopic analysis, allowing for speciation of elements and organic compounds analysis all in a single instrument package. Polar environment benefits include the potential elimination of the logistical train associated with ice sample shipment and management.
A limited study conducted in 2013 to establish the sensitivity of LIBS for detecting paleo-climate proxy indicators showed sufficient sensitivity to see Ca, K, Mg, and Na at the parts per million level (ppm). In addition, LIBS revealed peaks of C and CN consistent with the presence of organic material and the trace metals (Al, Cu, Fe, Mn, and Ti) at the parts-per-billion (ppb) level. The study showed LIBS is capable of micron-level spatial resolution, including analysis of individual particles embedded in the ice, by using a commercial LIBS instrument (Applied Spectra, Inc. RT100-EC) with a 50 mJ laser using the 266 nm wavelength. Other applications of interest include using LIBS to characterize (1) oil in ice; (2) energetic residues in soil; (3) forensic phenomenology of human markers on sorptive surfaces; (4) interrogation of battlespace surfaces for contaminant threats; and (5) classification of military munitions underwater.
The CRREL Biogeochemical Sciences Branch (BSB) has an ASI J200 LIBS instrument capable of analyzing solids (including ice) and liquids. CRREL also has facilities to evaluate field applications in a polar environment, underwater, or outdoors. The CRREL research staff has expertise in chemistry, soils, microbiology, analytical instrumentation operation and cold-weather instrumentation evaluation and re-engineering.
The BSB basic and applied research involving the use of LIBS is ongoing and funded through reimbursable projects. The focus of future research includes establishing LIBS operational parameters in a cold environment with temperatures down to −40°C and developing a fiber optic wand to allow down-hole analysis to eliminate the need for ice-core retrieval.
Cost, Distribution, and Support
A LIBS system can cost a third of the price of a traditional ICP-AES (inductively coupled plasma–atomic emission spectrometry) or MS (mass spectrometry) system. Therefore, LIBS makes this type of analysis more accessible for a wider range of projects. While CRREL research conducted on LIBS technology applications is still in the early stages, CRREL researchers have given LIBS-related presentations at the Polar Technology Conference in 2013 and at the LIBS 2014 and SciX Conferences. Contact CRREL to discuss how this technology might enhance your research.
ERDC Point of Contact
Jay Clausen, PhD