oEPA
The Need
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 93478
Las Vegas NV 89193-3478
January 1994
OFFICE OF RESEARCH AND DEVELOPMENT
TECHNOLOGY SUPPORT PROJECT
Immunochemical Analysis
Of Environmental
Samples
An EMSL-LV
Innovative
Technology
Immunochemistry
program
Field methods used for
detecting compounds of
environmental signifi-
cance traditionally have
been derived from
standard laboratory
methods. When labo-
ratory methods are
adapted to the field,
they are often relatively
slow, insensitive,
expensive, and require
bulky transportable
equipment and skilled
operators. There is a
need for rapid, sensi-
tive, low-cost, portable,
and simple field meth-
ods for analysis of
environmental samples.
Immunochemistry
offers those advan-
tages. The only spe-
cialized equipment
needed is a spectro-
photometer, microtiter
plates or test tubes,
precision pipets, and
immunologic reagents.
Commercial manufac-
turers sell kits for field
screening, and new
equipment and meth-
ods are being devel-
oped for rapid, accurate
field analysis of a wide
variety of analytes,
such as heavy metals,
dioxins, and PCBs, that
are found at Superfund
and RCRA sites. As a
result the regulator and
regulated communities
view immunochemistry
as a powerful technol-
ogy for screening
analysis of environmen-
tal contaminants.
Immunochemistry
includes techniques
such as immunoaffinity
chromatography and
immunoassay. Sample
preparations based on
immunoaffinity take
advantage of the
attraction between an
antibody and a specific
analyte. The procedure
has great potential for
cleanup of complex
samples like soils and
sludges. By rinsing a
sample over an anti-
body-treated surface,
chemists can isolate
particular compounds
that adhere to the
antibody. The isolated
compound is then
eluted from the immobi-
lized antibody and is
ready for analysis by
chromatography or
immunoassay. One
common immunoassay
is the enzyme-linked
immunosorbent assay
(ELISA). In this tech-
nique, the selectivity of
the antibody for the
analyte and the result-
ant antibody-analyte
complex is the basis for
the specificity of immu-
noassays.
9311-0146EX93ODC
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The Environmental
Monitoring Systems
Laboratory - Las Vegas
(EMSL-LV) is pioneer-
ing an investigation into
the usefulness of
immunochemical
techniques for monitor-
ing the extent of con-
tamination in environ-
mental and biological
matrices. EMSL-LV
has developed and
demonstrated several
of these techniques and
believes that they hold
great promise for the
quantitative analysis of
target analytes for use
in ground-water surveil-
lance, in situ hazardous
waste site monitoring,
and assessment of
human exposure.
Current work involves
the analysis of chemi-
cals like PCBs,
nitroaromatics, and
certain pesticides that
are difficult to analyze
by other analytical
methods. EMSL-LV
has sponsored two
national meetings that
focused on regulatory
issues and technologi-
cal advances in envi-
ronmental immuno-
chemistry. These
meetings brought
together government,
industry, and university
scientists to discuss
problems of mutual
interest in the field.
A 1993 Technology
Support Center project
at a Superfund site in
Region 5 demonstrated
the usefulness of
immunochemical
methods for screening
PCBs in soil and river
sediment. This project
was an example of
cooperation between
EPA, DOE, the state of
Michigan, and various
contractors. Two
immunoassays and a
chloride-ion specific
electrode were used on
site and the real-time
analytical results were
compared with stan-
dard GC results from
EPA method 8081.
Preliminary results
show good agreement
between the immuno-
assays and GC and
even stronger correla-
tion could be achieved
with tighter quality
control measures.
In addition, other EPA
offices have applied
immunochemistry for
screening and analysis
in their programs. The
Office of Water has
used immunoassays to
screen indirect discharges
of specific analytes for
permitting under the
Clean Water Act
(304h). Sample analy-
sis data may soon be
used for comparison
and compliance moni-
toring within selected
industries, such as
commercial laundries.
The Office of Pesticides
is looking at ways to
shorten the pesticide
registration process by
using immunochemistry
as a cost-effective
technology.
Other government
agencies and universi-
ties are studying immu-
nochemical methods.
The Food and Drug
Administration (FDA)
may use immunoas-
says to obtain data for
the calculation of safe
concentrations of
residues. A recent
university project used
immunoassays to track
contamination during
the 1993 Midwestern
flood. In applications
as diverse as organic
geochemistry and
military operations,
immunochemical
methods have been
used for volatile organic
compound measure-
ment. The U.S. Depart-
ment of Agriculture
(USDA) is integrating
immunoassays into
rapid test procedures
for detection of resi-
dues in meat and
poultry. Results from
these tests will be used
in regulatory and
compliance programs
for veterinary drugs,
sanitation, and pest
control. The National
Institute for Occupa-
tional Safety and Health
(NIOSH) has applied
immunoassays to
herbicide research,
clinical analysis,
biomarkers, and im-
mune biomonitoring.
They use the methods
to detect morphine
factor, alachlor, atr-
azine, cyanazine,
metalachlor, and 2,4-D.
State laboratories have
analyzed soil samples
and water from private
wells using immuno-
chemical test systems
for triazine (atrazine)
samples.
The results of EPA's
Superfund Innovative
Technology Evaluation
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The Use
(continued)
The Limits
(SITE) studies indicate
a strong correlation
between field immuno-
assays, laboratory
immunoassays, and
gas chromatography-
mass spectrometry.
Another field use of
immunochemistry that
is being explored at
EMSL-LV, the personal
exposure monitor
(PEM), may revolution-
ize safety and exposure
requirements for work-
ers who deal with
hazardous chemicals.
Immunochemical
dosimeter badges can
be used to detect
pentachlorophenol and
nitroaromatics, and are
being developed for
parathion and
chloropyrifos. These
badges are lightweight,
inexpensive, quick, and
provide a real time
indication of exposure.
The use of immuno-
chemical techniques is
gaining acceptance in
the environmental
sciences. One need
that is being addressed
is that of specificity.
Frequently, immunoas-
says are available for a
class of compounds,
like PCBs. Specific
quantitation for each
component has been
difficult.
The development of
PEMs, for example,
must address the
question of diffusion of
chemicals through a
semipermeable mem-
brane, the optimum
concentration of the
antibody, detection
limits of the PEM and
quantitation by immu-
noassay, the efficiency
of the antibody in
capturing the analyte,
and the capacity of the
device.
Validation studies of
reproducibility, matrix
effects, field trials, false
negatives/positives,
and correlation with
other tests will assist
acceptance of immuno-
chemical methods at
Superfund and RCRA
sites. The legal defensi-
bility of immunochemi-
cal results is yet to be
determined.
Advantages and limita-
tions are summarized
below.
Advantages
Limitations
• Field portable
• User friendly
• Quick and inexpensive
• Potential for wide range of
analytes
• Useful for many matrices
• Low detection limits
• Separate immunoassay needed
for each analyte
• More complex analysis required
for quantitation of specific
analytes
• Long development time for new
antibodies and methods
The Status
One new avenue of
investigation is the use
of antibody-coated,
fiber-optic immuno-
sensors. Another
application is the
integration of robotics
capability for high
sample throughput and
the development of a
tiered analytical ap-
proach, i.e., biological
and environmental
samples, biomarkers,
target analytes, and
degradation products.
This system of analyti-
cal procedures will
enable scientists to
measure contamina-
tion at the source,
follow the fate and
transport of residual
amounts, and assess
{continued on next page)
3
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The Status
(Continued)
References
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human exposure.
Multianalyte immunoas-
says that can identify
several analytes are
expected to expand the
desirability of immuno-
assay technology for
environmental use.
Work in this area is
already underway at
EMSL-LV and else-
where. Other applica-
tions of immuno-
chemistry, such as
multianalyte optical
immunobiosensors and
biorefractometry, are
being developed.
Industry recently
formed the Analytical
Environmental Immuno-
chemistry Consortium
(AEIC), which is focus-
sing on performance-
based method guide-
lines, method valida-
tion, and formation of
consensus on regula-
tory and technological
issues. The National
Technology Transfer
Center (NTTC) offers a
vehicle for collaborative
studies. Cooperative
Research and Develop-
ment Agreements
(CRADAs) between
industry and the gov-
ernment can be used to
promote technology
development and
licensing of immuno-
chemical applications.
The EMSL-LV has a
Technology Transfer
Office that is able to
coordinate CRADAs for
the development of
immunochemical
methods.
Immunochemical
Methods for Environ-
mental Analysis,
J. M. Van Emon and
Mumma, R. O., eds.
ACS Symposium
Series 442, Washing-
ton, DC, 1990, 229pp.
Immunochemistry
Summit Meeting II,
C. L. Gerlach and
D. A. Fuccillo, report-
ers. September 1-2,
1993, Las Vegas, NV.
Internal Report to
EMSL-LV.
Immunochemical
Methods for Environ-
mental Analysis,
J. M. Van Emon and
V. Lopez-Avila, Anal.
Chem., Vol. 64, No. 2,
1992.
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support q
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For further information about the immunochemistry program at the EMSL-LV,
contact:
Dr. Jeanette Van Emon
U.S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory
P.O. Box 93478
Las Vegas, NV 89193-3478
(702) 798-2154
For Information about using immunochemical methods at a Superfund or
RCRA site through the EMSL-LV Technology Support Center, contact:
Mr. Ken Brown, Director
Technology Support Center
U.S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory
P.O. Box 93478
Las Vegas, NV 89193-3478
(702) 798-2270
For information about the Technology Transfer Office at the EMSL-LV,
contact:
Mr. Eric Koglin
U. S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory
P.O. Box 93478
Las Vegas, NV 89193-3478
(702) 798-2432
The Technology Support Center fact sheet series is developed by
Clare L. Gerlach, Lockheed Environmental Systems & Technologies Company, Las Vegas
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