ASTM D1608-98(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D 1608–98 (Reapproved 2003)
Standard Test Method for
Oxides of Nitrogen in Gaseous Combustion Products
(Phenol-Disulfonic Acid Procedures)
This standard is issued under the fixed designation D 1608; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D1605 PracticesforSamplingAtmospheresforAnalysisof
Gases and Vapors
1.1 This test method describes the phenol-disulfonic acid
colorimetric procedure (1) for the determination of total
3. Terminology
oxides of nitrogen [nitrous oxide (N O) excepted] in gaseous
3.1 Definitions—For definitions of terms used in this test
effluents from combustion and other nitrogen oxidation pro-
method, refer to Terminology D1356.
cesses.
1.2 It is applicable to a concentration range of oxides of
4. Summary of Test Method
nitrogen as nitrogen dioxide (NO ) of 5 ppm to several
4.1 The gas sample is admitted into an evacuated flask
thousandpartspermillionbyvolume(fourtoseveralthousand
containing an oxidizing absorbing solution consisting of hy-
milligrams per dry standard cubic metre).
drogen peroxide in dilute sulfuric acid. The oxides of nitrogen
1.3 Since the grab sampling technique used takes a rela-
are converted to nitric acid by gas phase oxidation due to
tively small sample over a very short period of time, the result
oxygen in the sample and by the absorbent solution. The
obtained will be an instantaneous measure of the nitrogen
resulting nitrate ion is reacted with phenol disulfonic acid to
oxides and, therefore, will be representative of the emissions
produceayellowcompound(thetri-ammoniumsaltof6-nitro-
only if the gas stream is well mixed and the concentration
1-phenol-2,4-disulfonic acid), which is measured colorimetri-
constant with time. Multiple samples are recommended.
cally. Calibration curves, prepared from samples of known
1.4 The values stated in SI units are to be regarded as
nitrate content, are used to determine the amount of nitrate in
standard. The SI equivalents are in parentheses and may be
the sample with results expressed as nitrogen dioxide.
approximate.
1.5 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
5.1 This test method provides a means to measure the total
responsibility of the user of this standard to establish appro-
nitrogen oxides (NO ) content of gaseous emissions for pur-
x
priate safety and health practices and determine the applica-
poses such as determining compliance with regulations, study-
bility of regulatory limitations prior to use. (For more specific
ing the effect of various abatement procedures on NO emis-
x
safety precautionary information see 8.5 and Section 3.)
sions,andcheckingthevalidityofinstrumentalmeasurements.
2. Referenced Documents
6. Interferences (1, 2)
2.1 ASTM Standards:
6.1 Inorganic nitrates, nitrites, or organic nitrogen com-
D1193 Specification for Reagent Water
poundsthatareeasilyoxidizedtonitratesinterferewiththetest
D1356 Terminology Relating to Sampling andAnalysis of
method and give erroneously high results. The presence of
Atmospheres
certain reducing agents, for example, sulfur dioxide (SO ),
D1357 Practice for Planning the Sampling of the Ambient
may interfere by consuming part of the hydrogen peroxide in
Atmosphere
the absorbing solution to leave an inadequate amount for
reaction with the oxides of nitrogen. Halides lower the results,
butinterferencefromhalideion(andlead)arenegligibleinthe
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.03 on Ambient concentration usually encountered in combustion sources.
Atmospheres and Source Emissions.
6.2 The role of some of the constituents of combustion
Current edition approved April 10, 2003. Published June 2003. Originally
effluents as possible interfering substances has not been thor-
approved in 1958. Last previous edition approved in 1998 as D1608–98.
oughly investigated.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Withdrawn
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D 1608–98 (2003)
FIG. 1 Diagram of Typical Sampling Apparatus used for Determination of Oxides of Nitrogen by Test Method D 1608
7. Apparatus 7.13 Stopcock, Three-way, T-bore, with a 24/40 joint for
attachment to the sample collection flask, and a 12/5 spherical
7.1 The assembled sampling apparatus is shown in Fig. 1.
joint for attachment to the sampling probe.
7.2 Barometer, capable of measuring atmospheric pressure
7.14 Stopcock Grease, high vacuum, high temperature,
to 6250 Pa [62 mm Hg].
inert.
7.3 Bottles, 120-mL or 4-oz, glass or polyethylene, with
7.15 Thermometer, dial-type or glass, with 1°C [2°F] divi-
leak-free noncontaminating caps.
sionsandanapproximaterangefrom−5to50°C[25to125°F].
7.4 Evaporating Dishes, new condition, unetched borosili-
7.16 Vacuum Pump, portable, capable of evacuating the
cate glass or porcelain, about 200-mL capacity. Do not use
sample collection flask to a pressure of about 2.5 kPa [25 mm
platinum ware (7).
Hg] or less.
7.5 Mercury Manometer,open-endU-tube,1mm[or36in.]
7.17 Volumetric Flasks, 50, 100, 1000-mL capacity.
with 1-mm [or 0.1-in.] divisions.
7.18 Volumetric Pipets, 1, 2, 3, 4, and 5-mL capacity.
7.19 Water Bath or Steam Bath, operating at approximately
NOTE 1—An unbreakable, roll-up type is convenient for this applica-
tion. 100°C [212°F] (an electric hot plate is not suitable because it
tends to cause spattering and possible loss of sample).
7.6 Microburet, 10-mL capacity, with 0.01-mL divisions.
7.7 pH Paper, or litmus paper, covering the range from 7 to
8. Reagents
14 pH.
8.1 Purity of Reagents—Reagent grade chemicals shall be
7.8 Sample Collection Flask, Calibrated—Two-litre round-
used in all tests. Unless otherwise indicated, it is intended that
bottomglassflaskwithashortneck24/40standard-taperjoint,
all reagents shall conform to the specifications of the Commit-
protected against implosion or breakage with tape or foamed
tee onAnalytical Reagents of theAmerican Chemical Society,
plastic, with known volume.
where such specifications are available. Other reagents may
7.9 Sampling Probe, borosilicate glass, approximately
be used provided it can be demonstrated that they are of
6-mm inside diameter, fitted with a 12/5 spherical joint for
sufficiently high purity to permit their use without decreasing
attachment to the three-way stopcock on the sample collection
the accuracy of the determination.
flask, provided with a filter on the inlet end for removal of
8.2 Purity of Water—Unlessotherwiseindicated,references
particulate matter, long enough to extend from approximately
towatershallbeunderstoodtomeanreagentwaterconforming
one-third to halfway into the stack or duct (or at least 1 m
to Type III or better of Specification D1193.Additionally, this
beyondinsidewallofstacksgreaterthan2mindiameter),and
test method requires water that is nitrate-free as demonstrated
heated or insulated, or both, sufficiently well to prevent
by a low-blank absorbance reading (less than 0.002 nm) in
condensation of moisture while purging and sampling.
Section 5.
7.10 Spectrophotometer, or filter photometer, capable of
8.3 Absorbing Solution—Dilute 3.0 mLof hydrogen perox-
measuring absorbance at 405 nm.
ide (H O , 3%) to 100 mLwith sulfuric acid solution (H SO ,
2 2 2 4
3+997). A fresh solution shall be prepared weekly. Do not
NOTE 2—A wavelength of 400 nm was actually used in the Project
Threshold tests, but recent work (3, 6, 7) has shown that the absorbance expose to excessive heat or direct sunlight for prolonged time.
peak maximum is actually at 405 nm, which is therefore a better choice.
This change should tend to improve the precision and bias of the test
method.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
7.11 Squeeze-bulb,rubber,valvedforone-wayflowtopurge
listed by the American Chemical Society, see Analar Standards for Laboratory
sampling probe.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
7.12 Stirring Rod, polyethylene, to avoid scratching the
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
evaporating dishes. MD.
D 1608–98 (2003)
8.4 Ammonium Hydroxide (sp gr 0.90)—Concentrated am- the stack around the probe. Assemble as shown in Fig. 1,
monium hydroxide (NH OH). A fresh solution shall be used. making sure that all ground-glass joints have been properly
8.5 Fuming Sulfuric Acid (H SO · XSO ), 15 to 18 weight greased, and that all joints and fittings are tight and leak-free.
2 4 3
% free sulfur trioxide. Caution—Handle with care. Turn the flask stopcock to the evacuate position and evacuate
8.6 Hydrogen Peroxide (3 %)—Dilute 10 mL of concen- the flask to the incipient boiling of the solution. If the incipient
trated H O (30%) to 100 mL. A fresh solution shall be boiling of the solution cannot be seen, this will be indicated on
2 2
prepared each time new absorbing solution is prepared. the manometer by a low and constant reading (usually around
2.5 to 4.0 kPa [20 to 30 torr or 0.8 to 1.2 in. Hg]. Shut off the
NOTE 3—If the strength of the H O (30%) is in doubt, test as follows:
2 2
pump valve and then the pump. Check for leakage by observ-
Weigh accurately about 5 mL of the H O solution and dilute to exactly
2 2
ing the manometer for any pressure increase. Any increase
500 mL. To 20 mL of the dilute solution add 20 mL of H SO (1+9) and
2 4
greater than 1.33 kPa [10 torr or 0.4 in. Hg] over a 1-min
titrate with 0.1 N potassium permanganate (KMnO ) solution to a
permanentpinkcolor.Onemillilitreof0.1 NKMnO solution=0.001701
period is not acceptable; do not take a sample until the leakage
gofH O .
2 2 problem is corrected. Turn the flask stopcock to the purge
position. Using a pump or a valved rubber squeeze bulb,
8.7 Phenol (C H OH), pure white solid.
6 5
thoroughly purge the sampling probe and the flask stopcock
8.8 Phenol Disulfonic Acid Solution—Dissolve 25 g of
with the sample gas until the probe and stopcock are warmed
phenol in 150 mL of concentrated H SO (sp gr 1.84) by
2 4
to the gas temperature and free of condensate. If condensation
heatingonasteambath.Cool,add75mLoffumingH SO (15
2 4
remains, heat the probe and purge until the condensation
to 18% SO ) and heat on the steam bath at 100°C [212°F] for
disappears. With the pump valve and pump shut off, turn the
2 h. Cool and store in a dark glass-stoppered bottle. The
flask stopcock to the evacuate position and record the flask
solution should be colorless; it deteriorates on long standing.
temperature,thedifferenceinmercurylevelsinthemanometer,
Discard if a yellow color develops.
and the barometric pressure. The absolute pressure in the flask
8.9 Potassium Nitrate (KNO )—Dry in an oven at 105 to
is equal to the barometric pressure minus the manometer
110°C for 2 h just before preparation of the standard solution.
reading. Immediately, turn the stopcock to the sample position
8.10 Potassium Nitrate, Stock Standard Solution (1 mL = 1
sothatthegasenterstheflaskandthepressuresintheflaskand
mg NO )—Dissolve exactly 2.1980 g of dried KNO in water
2 3
thesamplelineareequalized(usuallyabout15saresufficient).
and dilute to 1 L in a volumetric flask.
Turn the stopcock to the purge position to seal the flask and
8.11 Potassium Nitrate, Working Standard Solution (1
allow the gas to remain in contact with the absorbing solution
mL = 100 µg NO )—Dilute 10 mL of the stock standard
overnight (see Note 5) at room temperature. For further
potassium nitrate solution (1 mL=1 mg NO ) to 100 mLwith
information on sampling, refer to Practice D1357 and Prac-
water in a volumetric flask.
tices D1605.
8.12 Sodium Hydroxide Solution (;1N)—Slowly add 40 g
ofsodiumhydroxide(NaOH)pelletsto800to900mLofwater
NOTE 4—The end 6 mm [ ⁄4 in.] of the male 24/40 standard-taper joint
in a 2-L beaker with stirring until all pellets are dissolved.
is not lubricated to minimize contact of the gas sample with stopcock
Dilute to 1 L with water and mix well. Store in an airtight
grease during absorption.
polyethylene or polypropylene bottle.
NOTE 5—If an overnight absorption period is not feasible, the sample
can be shaken initially and every 20 min for a 2-h period. The result will
8.13 SulfuricAcid(spgr1.84)—ConcentratedH SO ,mini-
2 4
not be significantly different than for a static overnight absorption period,
mum assay 95%.
provided that the oxygen concentration in the flask is greater than 1%.
8.14 Sulfuric Acid (3+997)—Carefully add 3 mL of con-
centrated H SO (sp gr 1.84) to water and dilute to 1 L.
2 4
11. Calibration
9. Safety Precautions
11.1 Sample Collection Flask Volume—Fillthesampleflask
and stopcock assembly with water up to the stopcock plug.
9.1 Cover the glass sample collection flask, which is evacu-
Determine the volume to 610 mL by measuring either the
ated during the sampling procedure, with tape or foamed
volume or weight of the water contained in the assembly.
plastic to avoid injury in case of implosion or breakage.
Number and record the volume on the flask.
9.2 The fuming sulfuric acid used in preparing the phenol
11.2 Spectrophotometer Calibration—Prepare a calibration
disulfonic acid reagent is highly corrosive and fumes in moist
curvetocoverarangefromabout0to125ppmNO ,basedon
air. Wear protective gloves, apron, and face shield, and carry 2
2000-mL samples of dry gas at 21°C [70°F] and 101.33 kPa
out the reagent preparation in a hood.
[760 torr 29.92 in. Hg]. Using a microburet or pipets, transfer
9.3 Concentrated acids and bases are used throughout the
0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 mL of the working standard
laboratory procedure. Use care when adding them to other
KNO solution (1 mL=100 µg NO ) into the 200-mL evapo-
solutions to avoid overheating and skin contact. 3 2
rating dishes and add 25.0 mL of absorbing solution to each.
10. Sampling
Proceed in accordance with 12.3 to 12.5. Construct a calibra-
tion curve by plotting the absorbencies of the solutions at 405
10.1 Pipet 25.0 mL of ab
...