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FREQUENTLY
ASKED QUESTIONS.
This
page was last updated April 04,
2005.
Click
on any of the following 29 questions to proceed directly to the question.
Q1:
Does the CAPE Technologies
dioxin kit have regulatory approval?
Q2:
Aren’t immunoassays for hazardous wastes a new and untested
technology?
Q3:
What is the “Triad Approach” to hazardous waste site assessment and
remediation, and what does Method
4025 have to do with it?
Q4:
What do I gain by using Method 4025 instead of Method 8290?
Q5:
If I don’t want to use the kit myself, can CAPE Technologies analyze my
samples for me?
Q6:
What exactly was Method 4025 intended for?
Q7:
What matrices can be analyzed by Method 4025?
Q8:
The matrix I want to analyze is not listed.
Can I still use the test?
Q9:
The EPA web site says Method 4025 is for screening at 500 ppt.
Is that all I can do with this
kit?
Q10:
How does this test work?
Q11:
What kind of result does the kit give?
Q12:
How long does it take to get results?
Q13:
How many samples can be analyzed in a day?
Q14:
Is Method 4025 just for yes/no results or can I generate quantitative data?
Q15:
Can I get individual congener values for my samples?
Q16:
What compounds does the kit detect?
Q17:
What is the detection limit of the kit?
Q18:
How reproducible are the kit results?
Q19:
How large a sample is needed for immunoassay analysis?
Q20:
How much sample cleanup is needed for immunoassay analysis?
Q21:
What kind of facility is needed for this method? Can I run this
test in
the field?
Q22:
What must I buy to get started and how much will it cost?
Q23:
How much does it cost per sample?
Q24:
How soon can I get started?
Q25:
How complicated is the test protocol?
Q26:
How much training is required?
Q27:
What if I need help while I am using the kit?
Q28:
Why isn't this kit as easy to use as the PCB and other immunoassay kits
I have used before?
Q29:
Does this test have problems with mass labeled internal standards?
Q1:
Does the CAPE
Technologies
dioxin kit have regulatory approval?
A1:
Yes. In 2001 the US EPA Office of
Solid Waste and Emergency Response
(OSWER)
accepted Method 4025 into the SW-846 Compendium of Solid Waste
Methods.
Method 4025 was developed around and is based on the CAPE
Technologies DF1
Dioxin/Furan Immunoassay Kit. This
kit is the only
commercially available immunoassay
product accepted by the US EPA for dioxin
analysis.
Method 4025 is posted on the new
methods section of the
EPA
OSWER SW-846 web site
Q2:
Aren’t immunoassays for hazardous wastes a new and untested
technology?
A2:
Definitely not. The 4000
series of solid waste screening methods
within
SW-846
includes methods such as for PCBs, PAHs, and petroleum fuels.
These
methods were
approved by the US EPA in the early 1990s and have been used
widely since then.
The CAPE Technologies DF1 Immunoassay is very similar in
principle to
the other
4000 series immunoassays and has been in commercial use
since 1997, receiving US
EPA acceptance in 2001 for use in Method 4025.
CAPE
Technologies Technical
Reference TR-005
(scroll down the document to get to the
beginning of the text)
describes the EPA-OSWER program for evaluation and
approval
of immunoassay
and related methods in
the 4000 series. The US EPA
has
embraced
a concept called
the “TRIAD
approach” to
hazardous waste site
assessment and
remediation, implementation of which explicitly requires
rapid
analytical methods
such as the 4000 series immunoassays.
Q3:
What is the “Triad Approach” to hazardous waste site assessment and
remediation, and what does Method
4025 have to do with it?
A3:
The “Triad Approach” is a systematic approach to streamlining the handling
of
waste sites. The strategy aims to
reduce overall costs and accelerate site
closures
by circumventing some of the bottlenecks in the conventional approach
to
site
closure.
Triad’s three parts are:
1) systematic and flexible planning;
2) on-site measurement technologies;
3) dynamic workplans.
The US EPA is currently trying to educate hazardous waste
site stakeholders
about the
benefits of this approach. From the
EPA
fact sheet on Triad :
“The US
EPA
supports
the adoption
of streamlined approaches to sampling, analysis, and
data management
activities conducted during site assessment, characterization,
and cleanup.
This position
reflects the growing trend towards
using smarter,
faster, and better technologies and
work strategies.” The report
further states:
“If used correctly, innovative rapid-turnaround field analytical and software
tools
coupled with on-site decision making
can significantly condense
a project’s
overall budget and lifetime, while significantly
increasing the likelihood that the
gathered data will guide transparent
decisions.”
Detailed
information about Triad is available from the EPA at website
http://clu-in.com/triad .
Of particular note are two recent articles
published by
staff
from the EPA Office of Technology Innovation in the journals
Remediation
and Quality
Assurance
Q4:
What do I gain by using Method 4025 instead of Method 8290?
A4:
First, Method 4025 should not be considered a replacement for
Method
8290 (the “conventional” dioxin method), but rather should be viewed
as a
complementary
method. Method 4025 does things
which Method 8290
cannot and vice versa.
Both methods are valuable tools to the analytical
chemist and site manager.
The advantages of Method 4025 include:
lower
cost;
higher sample
throughput;
faster turnaround
time;
and on site
analysis.
Most importantly, Method 4025 can allow you to utilize
the Triad
approach
described
by the US EPA (EPA
fact sheet on Triad))
in
ways that would not be
possible using
only
Method 8290. The
greatest benefit to you depends on your
individual
situation.
Reduced analytical costs can be very important, but there
are many other
factors to consider:
For soil remediation, the decrease in heavy equipment costs because of real
time
screening may be vastly greater than the reduction
in analytical costs.
For site assesment and mapping, the greatest benefit may be in completing
the
work
in a few weeks rather than several months.
For complex sites, the biggest advantage may be in being able to develop a
map
with
high enough spatial resolution to show the complexity of dioxin distribution.
A recent large scale implementation of Method 4025 is described in
CAPE
Technologies Technical Reference TR-006
.
Q5:
If I don’t want to use the kit myself, can CAPE
Technologies
analyze
my
samples for me?
A5:
Yes. As noted in our description of Products
& Services and our
Analytical Options Matrix , we also offer analytical services
based on our
own
products. We can also provide rapid turnaround to
support
rapid on-site
decision
making.
In many cases, results can be
reported
by
phone or email
the same
day
your samples
are received in our lab.
Contact CAPE Technologies
directly
to discuss specifics.
Q6:
What exactly was Method 4025 intended for?
A6:
The original design of Method 4025 was to provide semi-quantitative
screening
analysis in soil at 500 ppt, as described in detail in Application Note
AN-007
.
A modification of the sample preparation protocol
portion of Method
4025 (called
modified Method 4025 or 4025m) has
been validated for quantitative
soil analysis, as
described in Application Note AN-008
.
Other modifications of
this same
sample
preparation protocol expand the scope of the CAPE
Technologies DF1 Dioxin/Furan
Immunoassay Kit even further.
Q7:
What matrices can be analyzed by Method 4025?
A7:
At CAPE Technologies, we use Method 4025 and modifications of Method
4025 to
analyze soils, sediments, water, surface wipes, pulverized concrete,
hydrocarbon
oils,
food oils, feed additives, and a variety of other matrices.
If you want to use Method
4025 or 4025m in your lab, two Application Notes
describing soil analysis are
available,
as noted in the previous answer.
Applications
for other matrices have not yet been
released for use by customers,
but we will work with you to bring these methods
into
your lab if you wish.
Contact CAPE Technologies for
more detail.
Q8:
The matrix I want to analyze is not listed.
Can I still use the test?
A8:
Possibly. If we have no in house
application that can be transferred to you,
we will
work with you to develop the validation data necessary to support the
use
of the kit for your matrix.
Contact CAPE Technologies for
assistance.
Q9:
The EPA web site says Method 4025 is for screening
at 500 ppt.
Is
that all I can do with this kit?
A9:
Definitely not. The target for the
initial EPA Method 4025 validation was
selected
by the EPA as a practical level for many sites of interest (and also near
the
detection limit
of Method 8280, the low resolution
GC-MS method for dioxin).
The
EPA 4000 Series of methods allows kit
manufacturers to update methods
without
going through the validation process
again, as long as the changes are
minor and claims
of kit performance are supported by reliable data.
This conforms to the Performance
Based Measurement Systems (PBMS)
concept
supported by EPA OSWER since
the
early 1990s and summarized in section
6.3
of CAPE Technologies
Technical
Reference TR-005
.
Based
on this policy, we have provided data using the DF1 Dioxin/Furan
Immunoassay
Kit with a more rigorous cleanup. These data, in Application Note
AN-008
,
demonstrate quantitative correlation between
Methods 4025m and 8290
in the low to mid-ppt range.
Variations
of this cleanup, which is a simpler and much faster version of
that
used
for
Method 8290, have been used at CAPE Technologies to
analyze a wide
variety
of sample
matrices, in some cases as low as 0.5 ppt in solids.
PBMS
dictates that
the analyst
provide QA data to validate performance claims.
Such QA is a routine
part of our
analytical services. In addition,
our kit pricing
and cost per sample
estimates are based
on the assumption that 40% of each
immunoassay kit
will be
used for standards and
QA samples.
Q10:
How does this test work?
A10:
Several helpful schematic diagrams are given in the section on
Immunoassay Background . These
provide background
information
on
immunoassay
in general, plus a schematic depiction of
the DF1 test. A succinct
text
summary of the
principles behind the
DF1 kit is given in Section C of the kit
insert --
scroll down to Section
C of IN-DF1.
Q11:
What kind of result does the kit give?
A11:
The kit is designed to correlate with the toxic equivalent concentration
(TEQ)
contributed by polychlorinated dibenzodioxins and dibenzofurans
(PCDD/Fs).
The DF1
Dioxin/Furan Immunoassay correlates with TEQ because
response correlates with
toxicity of the individual congeners. Dioxin/furan
analysis by Method 8290 arrives
at the same TEQ number, which is the value
most commonly used
for regulatory
purposes.
Q12:
How long does it take to get results?
A12:
For samples analyzed in your lab, sample preparation time is the key
variable
and
may vary among applications. Same
day results are
possible for the
fastest sample
preparation methods, while other
applications
may require 24 hours.
Consult your
specific Application Note
or Contact CAPE Technologies
for more
specific information.
The
flexibility of the DF1 Dioxin/Furan Immunoassay also allows
the design of
methods
suited to specific situations. For
example, an engineering
firm testing a
pilot scale
dioxin destruction system requested
a same day method for screening
hydrocarbon oils
at 5 ppb. By modification
of both cleanup and immunoassay
protocol, they were able to
generate results
in 4 hours. For certain samples,
coupling of the immunoassay to
faster
extraction methods, such as supercritical
fluid extraction or
accelerated solvent
extraction, could reduce the analytical
cycle time
significantly.
For
samples analyzed by CAPE Technologies, standard turnaround is 10
business
days
from receipt of samples. Rush
turnaround (50% premium) is
5 business days
from
receipt of samples. Extra rush
turnaround (100%
premium) is 2 business days from
receipt of samples. Reports are
typically
delivered by email, with hard
copy backup
if desired.
Q13:
How many samples can be analyzed in a day?
A13:
Batch processing capability is an important part of the DF1 kit. Sample
throughput
depends on analyst skill and experience, as well as the sample
preparation
protocol used
and the number of quality assurance
samples.
The
customer cited in Technical Reference TR-006
analyzed as
many as 40
samples per
day (24 hour turnaround time), based on about 12 person-hours per
day.
Their total for
the project was 1100 samples in about 8 weeks, based on
4 batches per week.
They
used no automated equipment and performed Method
4025 as described in
Application
Note AN-007
in their own
laboratory.
The
study summarized in Application Note AN-008
utilized the split approach
under
Option 2 of the Analytical Options Matrix
. The
rate per day was 10-15
samples, broken down as follows.
The customer laboratory extracted 234
samples and reduced
the extracts to paraffin oil, requiring about 5 person days.
These samples were shipped
to CAPE Technologies, put through the coupled
column cleanup of AN-008
, and analyzed
by immunoassay, along with all the QA
samples noted in Table 1 of AN-008
. The
extract
cleanup and
analysis, including
dilutions for quantitation of high samples, required about
4 person-weeks.
Q14:
Is Method 4025 just for yes/no results or can I generate quantitative data?
A14:
Method 4025 was designed for making semi-quantitative decisions, but it is
possible
to develop quantitative results using Method 4025m, as described in
AN-008
.
For accurate absolute quantitation, you must use a
set of 4025m-8290 comparison
data
to verify the EIA calibration. You
must also include sufficient QA samples
to determine
that extraction recoveries and cleanup recoveries are acceptable.
For
either semi-quantitative or quantitative analysis, CAPE
Technologies
provides
a
downloadable Excel
spreadsheet
tool,
Calculation Module C
.
This tool performs
sigmoid curve fitting and calculation of sample
concentrations, so there is no need for
you to purchase additional
software.
Q15:
Can I get individual congener values for my samples?
A15:
No. The test result is a single value which is the sum of responses to all
the
individual congeners.
Q16:
What compounds does the kit detect?
A16:
Essentially only toxic dioxin and furan congeners.
Detection is structure
based,
as
noted in Answer 10 above. Specificity
data for individual congeners are
given in Table 2
of the Kit Insert -- scroll
to Table 2 in pdf document IN-DF1.
Strong recognition
by the
DF1 Dioxin/Furan Immunoassay generally requires
both the dioxin/furan core
structure
and the 2378- chlorination pattern.
For
example, test response to
non-toxic PCDD/Fs
is greatly reduced because of
their deviation from this chlorination pattern.
Recognition of
the PCBs most similar to 2378-TCDD (PCBs 77 and 126) is
very limited
because the core structure to which the chlorines are attached
is
not
a dioxin or furan.
When both core structure and chlorination
pattern
are changed, as for PCB 153,
there
is no detectable recognition.
Additionally,
the carbon column based cleanup procedure described in
Application
Note
AN-008
retains only the tetra and higher dioxin and furan
congeners,
discarding the trichloro- and lower dioxins
and furans, as well as
the PCB’s.
Q17:
What is the detection limit of the kit?
A17: The detection limit is 4 pg of
2378-TCDD, which is sufficient for ppt to ppb
level
analysis. The best accuracy and
precision are obtained with 10-20 pg of
2378-TCDD. More complete response data are given in
Table
1 of the Kit Insert
(scroll to Table 1
in IN-DF1
)
and in graphic
form as the starting values in
Calculation Module C
.
Detection limits
in the original sample will vary by matrix, the matrix load
(amount of
sample introduced into the immunoassay), and the degree of sample
cleanup used.
Low to mid pg/g levels for soils are
straightforward,
as shown by Application
Note
AN-008
.
A simple and
minor modification of that protocol allows for soil
analysis
below
10 pg/g. Some
food matrices are done easily at levels as
low as
0.5 pg/g. Clean water
with low particulate loads, such as finished drinking water,
can be
analyzed
as
low as
30 pg/L using a 2 to 4 L sample.
Q18:
How reproducible are the kit results?
A18:
Table
1 of the Kit Insert
(scroll
down to Table 1 of
IN-DF1)
of the kit
insert
includes
standard deviations for each data point which indicate excellent
reproducibility. The data
tables in Application Notes AN-007
and AN-008
provide
quantitative accuracy and
precision data from analysis of real soil
samples.
Q19:
How large a sample is needed for immunoassay analysis?
A19:
Solid sample sizes are generally 5 g, but the actual analysis may require
only
a
small
fraction of this or possibly more than this, depending on the target
sensitivity.
Sections
I-2 and
I-3 (scroll down to Sections I-2 and I-3 of
the
Kit Insert
IN-DF1
)
describe
how to determine the amount of sample to use for your
application.
Q20:
How much sample cleanup is needed for immunoassay analysis?
A20:
Because of the intrinsic specificity of the immunoassay, less cleanup is
required than
for Method 8290, but the exact amount
depends
primarily on the
target sensitivity. Generally, decision levels at or above 1 ppb TEQ can be done
with only a simple
liquid
oxidation of the extract such as in Application Note
AN-007
.
Lower
decision levels can
be reached using a simple one step coupled
column cleanup such as in Application
Note
AN-008
.
Q21:
What kind of facility is needed
for this method? Can I run this test in
the
field?
A21:
Electricity and a temperature controlled workspace are required, but
running water
is not. If your lab (fixed or field)
has the equipment noted in the
following answer, you will
be able to perform the test.
Q22:
What must I buy to get started and how much will it cost?
A22:
The minimal equipment required to perform the immunoassay procedure
is
described in Equipment List EL-001
and costs less than $2000 total.
The
equipment which
may be required to perform the sample preparation is
described in Equipment List
EL-002
.
It is best to look at specific Application
Notes, such as AN-007
and AN-008,
which contain lists of required supplies and
equipment.
Cost of
equipment for sample preparation will vary according to the
application,
but is
still quite modest and may already be covered by your present equipment.
If you choose
option 2 or 3 from the Analytical
Options Matrix (CAPE
Technologies does some or all
of the work), these requirements will be reduced
accordingly.
The
two sizes of immunoassay kit starter package kit
described in
Products
& Services are available to
all first time customers at reduced prices.
The large
starter package
(described in document ML-DF1-ST-B
)
provides
enough immunoassay
materials for training, with enough left over to analyze
30
to 50 samples. The
total expenditure for
equipment and the first
kit can be as l
ittle
as the cost of analyzing 4 or 5 samples by EPA Method 8290.
Q23:
How much does it cost per sample?
A23: It varies, but
is always a small fraction of the cost of Method 8290.
The Analytical Options Matrix
gives approximate prices for three different
options:
- if you analyze the samples;
- if CAPE Technologies
analyzes the samples;
- and if the
work is split.
Exact
costs may vary by geographic region, sample cleanup requirements, and
other
factors such as the proportion of immunoassay kit materials used for
quality
assurance.
Q24:
How soon can I get started?
A24:
If you are sending your samples to CAPE
Technologies
for
us to analyze,
we may
be able to provide results the same day we receive the samples.
If timing
is critical it
is best to contact
us directly to discuss specific details.
If
you are doing the analysis, CAPE Technologies can generally ship kits within
two
business days, often the same or next day. One
to four weeks of lead time
may be
needed for the required photometer equipment (see
EL-001
), which
is
purchased from
an outside vendor. This potential
delay can be avoided by
renting
a photometer from
CAPE Technologies.
Q25:
How complicated is the test protocol?
A25: Not
very complicated. Our most widely
used sample preparation
methods
are
described in detail and
summary form in AN-007
and AN-008
.
The
protocol
for the immunoassay is summarized in the Protocol
Summary (within document
PS-DF1) and
described in detail in the
Section J of the
kit insert (scroll
down to
Section
J of the document IN-DF1 ).
Q26:
How much training is required?
A26:
Not much. Some new users with
non-immunoassay analytical experience
have
mastered the technique with only telephone
assistance.
Most new users can
begin
producing useful data within the first 1 to 3 runs (one half or less of a large
kit). Training
at your facility or ours is possible at additional cost.
Note: If you have PowerPoint software on your computer,
you can view the online
AN-008
training presentation. This
PowerPoint presentation is 7.7 MB and will
take approximately one to two minutes to download for those who have broad-band
connection to the Internet. Please note that some browsers will allow
download
only, in which case download the presentation, and then play it with your
PowerPoint software.
For more
information Contact CAPE Technologies
Q27:
What if I need help while I am using the kit?
A27:
If the answer to your problem or question can not be found in our
extensive
web site
material or printed literature, contact us by email
or other
means .
CAPE Technologies does
not just manufacture kits. We have
extensive
experience in
applications development and technical service,
including
kit
troubleshooting. Our
final
product is customer satisfaction,
and
we will provide
whatever technical assistance is
required to help you achieve your analytical goal.
Q28:
Why isn't this kit as easy to use as the PCB and other immunoassay kits
I have
used before?
A28:
For the same reason that the average PCB lab will not perform a dioxin
analysis.
Conventional dioxin analysis (Method
8290) is far more expensive and
difficult than
PCB analysis by Method
8082 .
This is partly because
the
chemistry
of dioxin analysis
is intrinsically more difficult. A
major portion of
this difficulty is
due to the fact that
sensitivity targets are typically several
orders of magnitude
lower than for PCB
and
other analytes. This drives matrix
concentration factors to extreme levels and forces the
analyst to apply some
form of cleanup to sample
extracts.
However, the proportional
advantages of
Method 4025 in speed
and cost relative to Method 8290 are about the
same as
for PCB analysis by Method
4020 vs. Method 8082.
Q29:
Does this test have problems with mass labeled internal standards?
A29:
Yes and no. The immunoassay is based
on structural recognition rather
than on the
mass separation used by Method 8290. Therefore,
mass
labeled
internal standards,
which are structurally identical to native PCDD/Fs, can
interfere with the
immunoassay.
The most efficient and economically
advantageous use of the DF1 kit avoids
conventional mass labeled internal
standards.
However, it
is possible to create
immunoassay compatible internal
standards by slightly modifying existing
standard
mixtures.
For further information,
contact
CAPE
Technologies
.
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