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Environmental Technology
Verification Report
Field Portable X-ray Fluorescence Analyzer
Niton XL Spectrum Analyzer
EPA 600/R-97/150
March 1998
In April 1995, the U.S. Environmental Protection Agency (EPA) conducted
a demonstration of field portable X-ray fluorescence (FPXRF) analyzers.
The primary objectives of this demonstration were (1) to determine
how well FPXRF analyzers perform in comparison to a standard reference
method, (2) to identify the effects of sample matrix variations
on the performance of FPXRF, (3) to determine the logistical and
economic resources needed to operate these analyzers, and (4) to
test and validate an SW-846 draft method for FPXRF analysis. The
demonstration design was subjected to extensive review and comment
by the EPAs National Exposure Research Laboratory, EPA Regional
and Headquarters
Superfund technical staff, the EPAs Office of Solid WasteMethods
Section, and the technology developers.
Two sites were used for this demonstration: RV Hopkins and the ASARCO
Tacoma Smelter. RV Hopkins is an active steel drum recycling facility
and the site of a former battery recycling operation. It is located
in Davenport, Iowa. The ASARCO site is a former copper and lead
smelter and is located in Tacoma, Washington. The samples analyzed
during this demonstration, were evenly distributed between three
distinct soil textures: sand, loam, and clay. In addition, four
sample preparation steps were evaluated. The reference methods used
to evaluate the comparability of data were EPA SW-846 Methods 3050A
and 6010A, Acid Digestion of Sediments, Sludges, and Soils
and Inductively Coupled Plasma-AtomicEmission Spectroscopy,
respectively.
The FPXRF analyzers tested in this demonstration were designed to
provide rapid, real-time analysis of metals concentrations in soil
samples. This information will allow investigation and remediation
decisions to be made on-site more efficiently and can reduce the
number of samples that need to be submitted for confirmatory analysis.
Of the seven commercially available analyzers tested, one is manufactured
by Niton Corporation (the XL Spectrum Analyzer); two are manufactured
by TN Spectrace (the TN 9000 and TN Pb Analyzer); two are manufactured
by Metorex Inc. (the X-MET 920-P Analyzer and the X-MET 920- MP
Analyzer); one is manufactured by HNU Systems, Inc. (the SEFA-P
Analyzer); and one is manufactured by Scitec Corporation (the MAP
Spectrum Analyzer). The X-MET 940, a prototype FPXRF analyzer developed
by Metorex, was given special consideration and replaced the X-MET
920-P
for part of the RV Hopkins sample analyses. This environmental technology
verification report (ETVR) presents information relative to the
XL Spectrum Analyzer developed by Niton. Separate ETVRs have been
published for the other analyzers demonstrated.
No operational downtime was experienced by the Niton analyzer through
the 20 days required to conduct this demonstration. Quantitative
data was provided by the analyzer on a real-time basis. The XL Spectrum
Analyzer was configured to report arsenic, chromium, copper, lead,
and zinc. This analyzer used relatively short count times of 60
live-seconds for this demonstration. This relatively short count
time resulted in a high sample throughput, averaging between 20
and 25 samples per hour. The XL Spectrum Analyzer provided definitive
level data quality (equivalent to reference quality data) for lead,
andquantitative screening level data quality (not equivalent to
reference data but correctable with the analysisof confirmatory
samples) for arsenic, copper, and zinc. No data quality assessment
could be made forchromium since the short count time made the precision
and method detection limit measurements problematic.
This study showed that the Niton XL Spectrum Analyzer produced data
that exhibit a log10 -log10 relationship with the reference data.
The analyzer generally exhibited a lower precision compared to the
reference methods. The XL Spectrum Analyzer precision RSD was generally
between 6 and 14 percent at 5 - 10 times the method detection limit.
The analyzers quantitative results were based on a developer-set
calibration using the Compton Ratio method which required the use
of well defined site specific calibration standards. Sample homogenization
was the single most important factor influencing data comparability.
The site and soil texture variables did not show a measurable influence
on data comparability. This demonstration found that the analyzer
was generally simple to operate in the field. The operator
required no specialized experience or training. Ownership and operation
of this analyzer may require specific licensing by state nuclear
regulatory agencies. There are special radiation safety training
requirements and costs associated with this type of license.
The Niton XL Spectrum Analyzer is an effective tool for field use
and can provide rapid, real-time analysis of the metals content
of soil samples at hazardous waste sites. The analyzer can quickly
identify contaminated areas allowing investigation or remediation
decisions to be made more efficiently on-site, and thus reduce the
number of samples that need to be submitted for confirmatory analysis.
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Posted October 31, 2001
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