particles, but not so excessive as to cause the particles to fracture

Minimum sample time =
analytical DL
(Sample Rate) x (desired gas conc. DL)
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6.1.3
Glass wool - Precleaning and storage. (See Sec. 5.3.) 
6.1.4
Glassware - All glass components of the train should be cleaned thoroughly. The
following procedure has been found to be effective, but any protocol which consistently results
in contamination-free glassware is acceptable.
Soak all glassware in hot soapy water (Alconox® or equivalent).
Rinse with tap water to remove soap.
Rinse with distilled/deionized H O (three times).
2
Bake at 400
EC for 2 hours.
Rinse with methylene chloride (pesticide grade) (three times).
Rinse with toluene (pesticide grade) (three times).
Cap glassware with clean glass caps or cleaned aluminum foil.
Mark cleaned glassware with color-coded identification stickers.
Rinse glassware immediately before using with acetone and methylene chloride.
6.1.5
Because probe liners do not usually fit in glassware baths or ovens, they may be
rinsed three times with methylene chloride followed by three rinses with toluene, and sealed
during transport. 
6.2
Preliminary field determinations
6.2.1
Sample site - The sampling site and the minimum number of sampling points
should be selected according to Method 1 or as specified by the Agency. The stack static
pressure, temperature, and range of velocity pressures ()Ps) should be determined using
Method 2. The stack gas moisture content should be determined using Method 4, its
alternatives, previous data, or an engineering estimate. Stack gas O and CO concentrations
2
2
should be estimated and dry molecular weight should be calculated. These parameters are
used to estimate the isokinetic sampling rate settings.
6.2.2
Nozzle size - The nozzle size should be based on the range of velocity pressures
so that it is not necessary to change the nozzle size in order to maintain isokinetic sampling
rates.
6.2.3
Sampling duration - The total length of sampling time needed to obtain the
identified minimum sample gas volume is determined by comparing the anticipated average
sampling rate with the volume requirement. (Average sampling rate should be within 0.5 to
0.75 cfm.) The same time should be allocated to all traverse points defined by Method 1. To
avoid timekeeping errors, the length of time sampled at each traverse point should be an
integer or an integer plus one-half minute.
6.2.3.1
Calculation of length of the sampling duration - The minimum sampling
time required to achieve a minimum sample volume and the corresponding detection limit
(DL) are given below.
6.2.3.2
The following calculation is for a single isomer (i.e., 2,3,7,8-TCDF).
Detection limits for other isomers may need to be calculated as well. For this example,
it will be assumed that the analytical detection limit is 0.5 ng (actual analytical detection
limit will need to be specified for each test program).

Minimum sample time =
0.5 ng
0.85 m
3
/h x 0.1 ng/m
3
= 6.25 h
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6.2.3.3
At a sampling rate of 0.014 m /min (0.5 cfm), the sample volume per
3
hour will be 0.85 m /h. Assuming a desired stack gas concentration detection limit to be
3
0.1 ng/m , the minimum sample time required to collect 0.5 ng at concentration in the
3
stack of 0.1 ng/m would be:
3
6.2.3.4
The total sampling time should be greater than or equal to the minimum
total sampling time required to achieve the necessary detection limit. In addition, the
sampling time per point should be greater than 2 min (greater minimum time interval may
be specified by the Agency), and the sample volume corrected to standard conditions
shall exceed the required minimum total gas sample volume.
6.3
Calibration
Calibration of the apparatus is one of the most important functions in maintaining data quality.
The detailed calibration procedures for the sampling apparatus listed in this section can be found
in Method 5 and Method 0010. Table 4 summarizes the quality assurance functions for the
calibrations.
6.3.1
Metering system
6.3.1.1
Full dry gas meter calibration - The dry gas meter (DGM) in the meter
console of the sampling system should be fully calibrated against a primary standard
meter (wet test meter or spirometer) or alternatively against a second reference meter
(dry gas meter or critical orifice) that has been calibrated against a primary standard
meter. The procedure can be found in Method 5.
6.3.1.2
Post-test DGM calibration check - Following the test program, the full
calibration factor or meter Y should be checked by performing a post-test DGM
calibration check. Any secondary reference meters can be used. Three calibration runs
are conducted at the maximum vacuum reached during the testing. The average
post-test calibration factor should not deviate from the full DGM calibration factor by more
than 5%. Additional details on these procedures can be found in Method 5.
6.3.2
Temperature gauges - Each thermocouple should be permanently and uniquely
marked on the casting; all mercury-in-glass reference thermometers should conform to
ASTM E-1 63C or 63F specifications. Thermocouples should be calibrated in the laboratory
with and without the use of extension leads. If extension leads are used in the field, the
thermocouple readings at ambient air temperatures, with and without the extension lead,
should be noted and recorded. Correction is necessary if the use of an extension lead
produces a change greater than 1.5 percent.
6.3.2.1
Impinger, organic module, and dry gas meter thermocouples - For the
thermocouples used to measure the temperature of the gas leaving the impinger train
and the XAD-2® resin bed, three-point calibration at ice-water, room-air, and
boiling-water temperatures is necessary. The thermocouples should be accepted only
if the readings at all three temperatures agree to ± 2
EC with those of the absolute value
of the reference thermometer.

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6.3.2.2
Probe and stack thermocouple - For the thermocouples used to indicate
the probe and stack temperatures, a three-point calibration at ice-water, boiling-water,
and hot-oil-bath temperatures should be performed; it is recommended that room-air
temperature be added, and that the thermometer and the thermocouple agree to within
1.5% at each of the calibration points. A calibration curve (equation) may be constructed
and the data extrapolated to cover the entire temperature range suggested by the
manufacturer.
6.3.3
Probe heater - The probe heating system should be calibrated prior to field use
according to the procedure outlined in APTD-0576. Probes constructed according to
APTD-0581 need not be calibrated if the curves of APTD-0576 are used.
6.3.4
Barometer - The field barometer should be adjusted initially and before each test
series to agree within 2.5 mm Hg of the mercury-in-glass barometer or with the station
pressure value reported by a nearby National Weather Service station, corrected for elevation.
The correction for elevation difference between the station and the sampling point should be
applied at a rate of -2.4 mm Hg/30 m of elevation increase. The results should be recorded
on the pretest sampling check form.
6.3.5
Probe nozzle - Probe nozzles should be calibrated before initial use in the field.
The ID of the nozzle should be measured with a micrometer to the nearest 0.025 mm. Three
measurements should be made using different diameters each time and the average obtained.
The difference between the high and the low numbers should not exceed 0.1 mm. When
nozzles become damaged they should not be used again. Each nozzle should be permanently
and uniquely identified.
6.3.6
Pitot tube - The Type S pitot tube assembly should be calibrated using the
procedure outlined in EPA Method 2.
6.3.7
Balance - The balance should be calibrated initially by using ASTM Class 1
(Class S) standard weights and should be within 0.5 g of the standard weight.
6.4
Sampling train preparation - Care should be taken to ensure a clean sampling train
preparation area free of excessive dust and organic compounds for preparing the sampling train.
6.4.1
Preparation of impingers - During preparation and assembly of the sampling train,
all train openings where contamination can enter should be sealed until just prior to assembly
or until sampling is about to begin.
6.4.1.1
The first impinger should be left empty (used as a water knock-out
impinger due to long run times).
6.4.1.2
Approximately 100 mL of reagent water should be placed in the second
and third impingers. This method does not require that organic analyses be conducted
on the impinger contents. However, if analyses of semivolatile organic compounds are
to be conducted, then the proper specifications on cleaning the impingers and water
quality (i.e., HPLC-grade water) should be observed. 
6.4.1.3
Approximately 200 to 300 g of silica gel should be placed in the fourth
impinger. All impingers should be weighed separately to the nearest 0.5 g and the
weights recorded. Impingers should be connected with glass U-tube connectors.

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6.4.2
Filter loading - A filter should be placed in a properly-cleaned filter holder using
cleaned tweezers or clean disposable surgical gloves. The filter should be properly centered
and the gasket (if used) properly placed to prevent the sample gas stream from circumventing
the filter. The filter should be checked for tears after the assembly is completed.
6.4.3
Sorbent loading - The XAD-2® should be loaded and sealed in the analytical
(preparation) laboratory.
6.4.4
Final assembly - The final assembly of the filter holder, condenser, and sorbent
module can be performed at the stack location. All components should be sealed with either
precleaned foil or socket joints.
6.5
Sampling train leak check procedures - Leak checks are necessary to assure that the
sample has not been biased low by dilution air. Both pre-test and post-test leak checks are
necessary.
6.5.1
Pre-test - After the sampling train has been assembled, the train should be leak
checked at the sampling site by plugging the nozzle and pulling a 380 mm Hg vacuum.
Leakage rates greater than 4% of the average sampling rate or 0.00057 m /min, whichever is
3
less, are unacceptable. Leak checks should be conducted according to Method 5 criteria.
6.5.2
During the sampling - If a component (e.g., filter assembly, sorbent module, or
impinger) change is necessary during the sampling run, a leak check should be conducted
before the change. The leak check should be done according to the procedure outlined above,
except that it should be at a vacuum equal to or greater than the maximum value recorded up
to that point in the test. If the leakage is less than 0.00057 m /min or 4% of the average
3
sampling rate (whichever is less), the results are acceptable. If, however, a higher leakage
rate is obtained, the tester should record the leakage rate and either void the sampling run or
perform sample volume leak corrections (if approved by the Agency). After replacing the train
component, an initial leak check should be completed before sampling.
6.5.3
Post-test - The leak check should be completed at a vacuum equal to or greater
than the maximum value reached during the sampling run. If the leakage rate is less
than 0.00057 m /min or 4% of the average sampling rate (whichever is less), the results are
3
acceptable. If, however, a higher leakage rate is obtained the tester shall either void the
sample run or perform sample volume leak corrections (if approved by the Agency).
6.6
Sampling train operation
6.6.1
Final pre-test sampling checks - After conducting the initial leak check, the
following checks should be made:
@
Meter box examination
@
Manometers leveled and zeroed
@
Pump checked for proper operation
@
Pitot lines leak checked
@
Probe markings verified
@
Thermocouples reading correctly
@
Size and orientation of the nozzle verified
@
Method 3 equipment for CO /O checked for proper assembly and leak checked and
2
2
@
Isokinetic K-factor checked to ensure that it is correct.

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Immediately prior to sampling:
@
Portholes should be cleaned to minimize the chance of sampling deposited material
@
Probe and filter heating system temperatures should be checked
@
Condenser/sorbent cooling system temperatures should be checked and
@
Proper nozzle location should be verified.
6.6.2
The sampling procedure below should be followed.
6.6.2.1
Sampling - Initial dry gas meter readings, barometric pressure, and
temperatures should be recorded. The tip of the probe should be positioned at the first
sampling point with the nozzle tip pointing directly into the gas stream. When the probe
is in position, the open area around the probe and the porthole should be blocked off to
prevent flow disturbances and non-representative dilution of the gas stream. The pump
should be turned on and the sample flow adjusted immediately to attain isokinetic
conditions. The Method 3 sampling system should be turned on. Velocity pressures
should be recorded and the sampling rate adjusted to isokinetic. Other readings of
velocity pressure ()P), orifice pressure ()H), stack gas temperature (T ), probe
s
temperature (T ), filter temperature (T ), sorbent trap temperature (T ), silica gel impinger
p
f
t
temperature (T ), dry gas meter inlet and outlet temperatures (T ), dry gas meter
sg
m
volume, and sample vacuum should be made.
6.6.2.2
The stack should be traversed as directed in Method 5 procedures. At
each sample point, the above readings should be taken and sample flow rates adjusted
to isokinetic. Following the traverses, the pump is turned off, the probe removed from
the stack, and the final DGM readings recorded. Care should be taken not to bump the
nozzle against stack walls in order to minimize the chance of breakage or extracting
deposited material. Following each port traverse, a leak check is recommended in order
to ensure a leak tight system. An additional leak check may also be performed after the
train is moved to the next port, prior to sampling. The necessary post-test leak check
should be conducted and the leak rate recorded.
6.6.2.3
Periodically during the test run, the connecting glassware from the
probe, through the filter, and to the condenser should be checked for water
condensation. If any condensation is evident, verify that the temperature sensors and
heater systems are functioning properly. Ice should be maintained around the impingers
to keep both the sorbent trap entrance and silica gel exit temperature at 20
EC. Filter
vacuum should be checked for sudden increases. The filter should be changed if the
vacuum exceeds 15 in. Hg. The manometer level and zero should also be checked
periodically during each traverse, because vibrations and temperature fluctuations can
cause the manometer zero to shift.
6.6.2.4
Following the post-test leak check, the probe should be disconnected,
and the nozzle and the end of the probe capped with precleaned aluminum foil, or
equivalent caps. The inlet to the filter holder should be capped according to one of the
methods previously mentioned. It may be necessary to loosen the seal between the
sorbent module outlet and the inlet to the first impinger to prevent water from being
drawn back into the module when the sample train cools. Alternatively, the filter holder,
condenser and sorbent module may be disassembled and immediately capped at the
stack location and removed to the sample recovery area.

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6.7
Collection of blanks - Four different sampling blanks should be collected: field blanks,
reagent blanks, proof blanks, and method blanks (laboratory only). Only two sampling blanks should
be analyzed initially: the field blank and the laboratory method blank. If the field blank has high
levels of contamination and the laboratory blank does not show high background levels of
PCDD/PCDF, the other blanks should be analyzed to help determine the source of the
contamination. Blanks are further discussed in Sec. 8.0.
7.0
PROCEDURE
7.1
Recovery preparation - Proper recovery procedure begins as soon as the probe is
removed from the stack at the end of the sampling period. The nozzle end of the sampling probe
should be sealed with precleaned aluminum foil and disconnected from the filter holder. When the
probe is cool enough to be handled safely, all external particulate matter near the tip of the probe
should be wiped off and both ends of the probe closed off with aluminum foil. Both openings to the
filter holder, transfer line (if used), condenser, sorbent trap, and impinger train should be
disconnected and sealed. Care should be taken not to lose any condensed water upstream of the
impingers (if present) during this process.
Train components should be transferred to the cleanup area. This area should be clean and
enclosed so that the chances of losing or contaminating the sample are minimized. Smoking, which
could contaminate the sample, is not allowed in the cleanup area. Cleanup personnel should wash
their hands prior to sample recovery. The train should be inspected prior to and during disassembly
and any abnormal conditions, e.g., broken filter, colored impinger liquid, etc., noted.
7.2
Sample recovery procedure - As shown in Figure 3, the sampling train should be
recovered into four containers. The procedures applicable to each sample container are briefly
discussed in the following section.
7.2.1
Filter (Container 1) - The filter should be removed carefully from the filter holder
and placed in its identified container. Cleaned tweezers should be used to handle the filter.
Fold the filter, if necessary, with the particulate cake inside the fold. Any particulate matter and
filter fibers which adhere to the filter holder gasket should be transferred to the container by
using a dry inert bristle brush and a sharp-edged blade. The container should be sealed with
Teflon® tape.
7.2.2
Front half rinse (Container 2) - Quantitatively recover material deposited in the
nozzle, probe liner, probe transfer line, cyclone (if used), and the front half of the filter holder.
Brush while rinsing three times each with acetone and then rinse three times with methylene
chloride. All rinses should be put into Container 2. The outside of the probe, the pitot tube,
and the nozzle should be cleaned to prevent particulates from being brushed into the sample
bottle. The probe liner should be tilted and rotated while squirting acetone into the upper end
to assure complete wetting of the inside surface. Acetone is then squirted into the upper end
while pushing the probe brush through the liner with a twisting motion, with the drainage
caught in the sample bottle (Container 2). The brushing procedure should be repeated two
more times or until no particles are visible in the drainage and a visual inspection of the liner
reveals no particles remaining inside. The brush should be rinsed into the sample bottle to
collect any particulates that may be retained within the bristles. The three acetone rinses are
followed with methylene chloride and two rinses with toluene allowing the rinsate to collect into
the same sample container.

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After all the rinsings have been collected, the lid on the sample container should be
tightened securely. As a precaution in case of leakage, the liquid level should be marked on
the sample container and the cap sealed with Teflon® tape. The sample recovery should be
recorded on the sample recovery form.
7.2.3
Sorbent module (Container 3) - The sorbent module should be removed from the
train, tightly capped at both ends with aluminum foil or glass caps, labeled and stored on ice
for transport to the laboratory. Care should be taken to ensure that no ice water can leak into
the stored traps or any other train component.
7.2.4
Back half rinse (Container 4) - Rinse the back half of the filter holder, the
connecting line between the filter holder and the condenser, and the condenser itself (if
separate from the trap) three times with acetone, followed by two rinses with methylene
chloride and two rinses with toluene. The sample container (Container 4) is then identified and
sealed as discussed above.
7.2.5
Impinger water - Any color or film in the impinger water should be noted on the
sample recovery form. The entrained moisture in the first three impingers should be measured
to within ± 1 mL by using a graduated cylinder or by weighing to within 0.5 g by using a
balance, and the data recorded appropriately. This information is needed to calculate the
moisture content of the effluent gas. If the sampling train catch is to be analyzed exclusively
for dioxins and furans, then the impinger liquid may be discarded after the volume or weight
is recorded.
7.2.6
Silica gel - The color of the indicating silica gel should be noted on the recovery
form to determine if it has been completely spent and the impinger weighed to determine
entrained moisture weight gain. Analysis is not required.
7.3
Analysis summary - The following section summarizes the analytical procedures for
quantitating PCDD/PCDF collected by the sampling train. Sample preparation procedures and the
basic analytical techniques are listed. The detailed analytical protocol can be found in Method 8290.
7.3.1
As shown in Figure 4, the analytical procedure requires the sampling train to be
analyzed in two fractions. Containers 1 and 2 (filter and front half rinse) are combined and
analyzed. Containers 3 and 4 (sorbent trap and back half rinse) are also combined and
analyzed. In this way filter surrogate standard recoveries and XAD-2® surrogate standard
recoveries are both determined separately.
7.3.2
Acceptance criteria and corrective actions for surrogate recoveries are as follows:
7.3.2.1
All PCDD/PCDF surrogate recoveries should be within 70 to
130 percent.
7.3.2.2
If all isomer recoveries are greater than 130 percent, the sampling runs
should be repeated,
7.3.2.3
If all isomer recoveries are less than 70 percent, the sampling runs
should either be repeated or the final results should be divided by the fraction of
surrogate recovery.
7.3.2.4
If some of the isomer recoveries are within the acceptance range and
some are not, then the final results for the isomers outside the range should be divided

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by the fraction of the surrogate recovery, the resulting corrected results should be flagged
in the data tables, and a discussion should be included in the final report.
7.3.2.5
Acceptance criteria for other standard recoveries (i.e., internal) should
conform to Method 8290 requirements.
7.3.3
As discussed in Secs. 5.1.2 and 5.2.1, surrogate spikes are added to the sorbent
trap prior to sampling and to the filter immediately prior to extraction. The same set of
isotopically-labeled compounds is used for these spikes. The analytical procedure for both
fractions is given in the following sections. All samples should be extracted within 30 days of
collection and analyzed within 45 days of extraction.
7.3.4
Sample preparation and internal standard addition - The following procedure
should be performed for the filter/front half analysis and the sorbent trap/back half analysis.
The only difference between the two procedures is that surrogate standards are added to the
filter/front half fraction immediately prior to sample preparation whereas the surrogate
standards have already been added to the sorbent trap/back half prior to sampling.
7.3.4.1
Filter/front half fraction procedures - Place a cellulose extraction thimble,
1 g of silica gel or sodium sulfate, and a plug of glass wool into the Soxhlet apparatus,
charge the apparatus with toluene, and reflux for a minimum of 3 hours. Remove the
toluene and discard it, but retain the silica gel. Remove the extraction thimble from the
extraction system and place it in a glass beaker to catch the solvent rinses.
7.3.4.2
Add exactly 1.0 mL of the surrogate spiking solution (Sec. 5.1.2)
uniformly onto the surface of the filter while it is still in the petri dish in which it was
returned from the field, using an adjustable pipet. Transfer the filter directly to the
extraction thimble of the extraction system. Rinse the petri dish with 10 mL of toluene
three times collecting the rinsate into the beaker.
7.3.4.3
Concentrate the sample in Container 2 (acetone/ methylene chloride
rinses) to a volume of about 1-2 mL using a Kuderna-Danish concentrator apparatus,
followed by nitrogen blow down at a temperature of less than 37
EC. Rinse the sample
container three times with small portions of methylene chloride and add these to the
concentrated solution and concentrate further to near dryness. This residue contains

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