September 2014 Update: EPA has validated and published a rapid method for sodium hydroxide fusion
of concrete and brick matrices for analysis of americium-241, plutonium-238, plutonium-239, radium-
226, strontium-90, uranium-234, uranium-235 and uranium-238. The method is summarized and
accessible through the link provided below.
Rapid Method for Sodium Hydroxide Fusion of Concrete and Brick Matrices Prior to
Americium, Plutonium, Strontium, Radium, and Uranium Analyses for Environmental
Remediation Following Radiological Incidents
Analyte(s)
Americium-241
Plutonium-238
Plutonium-239
Radium-226
Strontium-90
Uranium-234
Uranium-235
Uranium-238
CASRN
14596-10-2
13981-16-3
15117-48-3
13982-63-3
10098-97-2
13966-29-5
15117-96-1
7440-61-1
Analysis Purpose: Qualitative analysis
Technique: Alpha spectrometry
Method Developed for: Americium-241, plutonium-238, plutonium-239, radium-226, strontium-90,
uranium-234, uranium-235 and uranium-238 in concrete and brick samples
Method Selected for: SAM lists this method for qualitative analysis of americium-241, plutonium-238,
plutonium-239, radium-226, strontium-90, uranium-234, uranium-235 and uranium-238 in concrete or
brick building materials
Description of Method: Concrete and brick samples may be received as core samples, pieces of various
sizes, dust or particles (wet or dry) from scabbling, or powder. Concrete or brick samples should be
ground to at least 50 - 100 mesh size prior to fusion, if possible. The method is based on the rapid fusion,
in zirconium crucibles, of a representative, finely ground 1-1.5 gram aliquant using rapid sodium
hydroxide fusion at 600 °C. Plutonium, uranium, and americium are separated from the alkaline matrix
using an iron/titanium hydroxide precipitation (enhanced with calcium phosphate precipitation) followed
by a lanthanum fluoride matrix removal step. Strontium is separated from the alkaline matrix using a
carbonate precipitation, followed by a calcium fluoride precipitation to remove silicates. Radium is
separated from the alkaline matrix using a carbonate precipitation. The method is applicable to the
sodium hydroxide fusion of concrete and brick samples, prior to the chemical separation procedures
described in the following procedures:
• Rapid Radiochemical Method for Americium-241 in Building Materials for Environmental
Remediation Following Radiological Incidents
• Rapid Radiochemical Method for Plutonium-238 and Plutonium-239/240 in Building Materials for
Environmental Remediation Following Radiological Incidents
• Rapid Radiochemical Method for Radium-226 in Building Materials for Environmental Remediation
Following Radiological Incidents
• Rapid Radiochemical Method for Total Radiostrontium (Strontium-90) in Building Materials for
Environmental Remediation Following Radiological Incidents
• Rapid Radiochemical Method for Isotopic Uranium in Building Materials for Environmental
Remediation Following Radiological Incidents
U.S. Environmental Protection Agency EPA/600/F-14/285
Office of Research and Development, Homeland Security Research Program September 2014
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Special Considerations: Large amounts of extraneous debris (pebbles larger than one quarter inch, non-
soil related debris) are not generally considered to be part of a concrete or brick matrix. When consistent
with data quality objectives (DQOs), these materials should be removed from the sample, prior to drying.
In those samples where native constituents may be present that could interfere with the determination of
the chemical yield (e.g., strontium for strontium-90 analysis) or with the creation of a sample test source
(e.g., barium for radium-226 analysis by alpha spectrometry), it may be necessary to determine the
concentration of the native constituents in advance of chemical separation (using a separate aliquant of
fused material) and make appropriate adjustments to the yield calculations or amount of carrier added.
Re-used zirconium crucibles should be cleaned very well using soap and water, followed by warm nitric
acid, and a final water rinse. Blank measurements should be monitored to ensure effective cleaning.
Additional information regarding potential interferences and procedures for addressing the interferences
is provided in Section 4 of the method.
Source: U.S. EPA, National Air and Radiation Environmental Laboratory (NAREL). April 2014. Rev 0
"Rapid Method for Sodium Hydroxide Fusion of Concrete and Brick Matrices Prior to Americium,
Plutonium, Strontium, Radium, and Uranium Analyses for Environmental Remediation Following
Radiological Incidents," EPA 402-R-14-004. http://www.epa.gov/sam/pdfs/EPA-402-R14-004.pdf
U.S. Environmental Protection Agency EPA/600/F-14/285
Office of Research and Development, Homeland Security Research Program September 2014
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