STACK SAMPLING 1111
titration with either 0.01 N sodium thiosulfate or phenylar-
sine oxide.
The EPA Test Method 11 write-up contains detailed
instructions for calibrations, leak check procedure, sampling,
and calculations, along with a list of references. It should be
read in detail before the Method is attempted. As with all of
these methods, testing should be performed only by trained
and experienced personnel using equipment and the titrations
required by this method.Test Method 12Test Method 12 is used for the determination of inorganic
lead (Pb) emissions from stationary sources. Both particulate
and gaseous forms of lead are measured by this method.
The sampling train is identical to the Method 5 train.
The water in the first two impingers is replaced by dilute
nitric acid to collect any gaseous lead emissions, convert-
ing them to the nitrate. The filter is not weighed. Instead it
is treated with acid to dissolve the lead compounds, which
are then analyzed using atomic absorption spectroscopy. The
impinger liquid is evaporated to 15 ml and digested accord-
ing to the instructions in the method. Once the sample from
the impingers is prepared, it is also analyzed by atomic
absorption spectroscopy.
The EPA Test Method 12 write-up contains detailed
instructions for calibration, leak check procedure, sampling,
and analysis, along with a list of references. It should be
read in detail before the Method is attempted. Analysis of
audit samples, prepared and distributed by EPA’s Emissions,
Monitoring and Analysis Division, is required. As with all of
these methods, testing should be performed only by trained
and experienced personnel using the equipment and atomic
absorption spectrometer required for this analysis.Test Method 13ATest Method 13A is used for the determination of inorganic
fluoride from stationary sources as specified in the regula-
tions. It does not measure organic fluorine compounds such
as the chlorofluorocarbons (freons).
The sampling train for Method 13A is similar to the
Method 5 train, except that the filter can be located either in
the standard position or placed behind the third and fourth
impingers. If the filter is placed before the impingers, it
should be either paper or organic membrane such that it
will withstand temperatures up to 135ºC and retain at least
95% of 0.3 μ m particles. Distilled water is used in clean-up
instead of the acetone used in Method 5.
The total fluoride concentration of the combined filter,
probe wash, and impinger contents is determined using the
SPADNS Zirconium Lake Colorimetric Method. The sample
preparation procedure includes breaking up of the filter,
evaporating of the water and fusing with NAOH at 600ºC.
The remaining ash is acidified with H 2 SO 4 , then distilled at
175ºC. SPADNS reagent is added to a suitable aliquot of
the distillate and the absorbance at 570 nm compared with
standard solution.The EPA Test Method 13A write-up contains detailed
instructions for sample preparation, calibrations, sample
analysis, blanks analysis, and calculations, along with a list
of references. It should be read in detail before the Method
is attempted. As with all of these methods, testing should be
performed only by personnel trained and experienced with
the equipment, chemicals, and the analytical procedures
required by this method.Test Method 13BTest Method 13B is used for the determination of fluoride
emissions from stationary sources. It uses the same sampling
and sample preparation procedures as Method 13A. Analysis
is with specific ion electrode method instead of the spectro-
photometric method used there.
The EPA Test Method 13B write-up contains instructions
for calibration along with a list of references. The manual for
the specific ion electrode and the meter should be consulted
before using this equipment. As with all of these methods,
testing should be performed only by personnel trained and
experienced with the equipment, chemicals, and the analyti-
cal procedures required by this method.Test Method 14Test method 14 provides guidance for setting up a sampling
system for fluoride emissions from potroom roofs at pri-
mary aluminum plants. Gaseous and particulate emissions
are drawn into a permanent sampling manifold through sev-
eral large nozzles. The sample is then transported from the
sampling manifold to ground level where it is sampled and
analyzed by either Method 13A or 13B.
Anemometers are required for velocity measurements
in the roof monitors (the large roof vents at such places).
These anemometers are required to meet the specifications
in the method for construction material, accuracy, etc. One
anemometer is required for every 85 meters of roof monitor
length. For roof monitors less than 130 meters, two anemom-
eters are required.
An industrial exhaust fan is attached to the sample duct.
The fan capacity must be adjustable and have sufficient
capacity to permit isokinetic sampling. The fan is adjusted
to draw a volumetric flow rate such that the entrance velocity
into each manifold nozzle approximates the average effluent
velocity in the roof monitor. A standard pitot tube is used
for the velocity measurement of the air entering the nozzles
because the standard pitot obstructs less of the cross section
than a Type S pitot tube.
The EPA Test Method 14 write-up contains detailed
instructions for the set-up, calibration, and use of permanent
manifolds for sampling emissions from potroom roof moni-
tors at aluminum plants. It should be read in detail before
considering the installation of this type of system.Test Method 15Test Method 15 uses gas chromatography for the determination
of hydrogen sulfide (H 2 S), carbonyl sulfide (COS), and carbonC019_003_r03.indd 1111C019_003_r03.indd 1111 11/18/2005 11:07:16 AM11/18/2005 11:07:16 AM