ASTM D888-92(1996)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact
ASTM International (www.astm.org) for the latest information.
Designation: D 888 – 92 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Methods for
Dissolved Oxygen in Water
This standard is issued under the fixed designation D 888; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number 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. Consult the DoD Index of Specifications and
Standards for the specific year of issue which has been adopted by the Department of Defense.
1. Scope the final measurement is derived.
3.2.2 instrumental probes,, n—devices used to penetrate
1.1 These test methods cover the determination of dissolved
and examine a system for the purpose of relaying information
oxygen in water. Two test methods are given as follows:
on its properties or composition. The term probe is used in
Range, mg/L Sections
these test methods to signify the entire sensor assembly,
Test Method A—Titrimetric Procedure–High Level >1.0 8 to 14
Test Method B—Instrumental Probe Procedure 0.05 to 20 15 to 23
including electrodes, electrolyte, membrane, materials of fab-
rications, etc.
1.2 The precision of Test Methods A and B was carried out
3.2.3 potentiometric systems,, n—those instrumental probes
using a saturated sample of reagent water. It is the user’s
in which an electrical potential is generated and from which the
responsibility to ensure the validity of the test methods for
final measurement is derived.
waters of untested matrices.
1.3 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
4.1 Dissolved oxygen is required for the survival and
responsibility of the user of this standard to establish appro-
growth of many aquatic organisms, including fish. The con-
priate safety and health practices and determine the applica-
centration of dissolved oxygen may also be associated with
bility of regulatory limitations prior to use. For a specific
corrosivity and photosynthetic activity. The absence of oxy-
precautionary statement, see Note 17.
gen may permit anaerobic decay of organic matter and the
production of toxic and undesirable esthetic materials in the
2. Referenced Documents
water.
2.1 ASTM Standards:
5. Purity of Reagents
D 1066 Practice for Sampling Steam
D 1129 Terminology Relating to Water
5.1 Purity of Reagents—Reagent grade chemicals shall be
D 1193 Specification for Reagent Water
used in all tests. Unless otherwise indicated, it is intended that
D 2777 Practice for Determination of Precision and Bias of
all reagents shall conform to the specifications of the Commit-
Applicable Methods of Committee D-19 on Water
tee on Analytical Reagents of the American Chemical Soci-
D 3370 Practices for Sampling Water from Closed Con-
ety. Other grades may be used if it is first ascertained that the
duits
reagent is of sufficiently high purity to permit its use without
E 200 Practice for Preparation, Standardization, and Stor-
lessening the accuracy of the determination.
age of Standard and Reagent Solutions for Chemical
5.1.1 Reagent grade chemicals, as defined in Practice E 200,
Analysis
shall be used unless otherwise indicated. It is intended that all
reagents conform to this standard.
3. Terminology
5.2 Unless otherwise indicated, reference to water shall be
3.1 Definitions—For definitions of terms used in these test
understood to mean reagent water conforming to Type II of
methods, refer to Terminology D 1129. Specification D 1193.
3.2 Definitions of Terms Specific to This Standard:
6. Sampling
3.2.1 amperometric systems,, n—those instrumental probes
6.1 Collect the samples in accordance with Practices
that involve the generation of an electrical current from which
D 1066 and D 3370.
These test methods are under the jurisdiction of ASTM Committee D-19 on
Water and are the direct responsibility of Subcommittee D19.05 on Inorganic Reagent Chemicals, American Chemical Society Specifications, American
Constituents in Water. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Current edition approved June 15, 1992. Published September 1992. Originally listed by the American Chemical Society, see Analar Standards for Laboratory
published as D 888 – 46T. Last previous edition D 888 – 81 (1987).e Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Annual Book of ASTM Standards, Vol 11.01. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 15.05. MD.
NOTICE:¬This¬standard¬has¬either¬been¬superceded¬and¬replaced¬by¬a¬new¬version¬or¬discontinued.¬
Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
D 888
6.2 For higher concentration of dissolved oxygen, collect 8.2 This test method, with the appropriate agent, is usable
the samples in narrow mouth glass-stoppered bottles of with a wide variety of interferences. It is a combination of the
300-mL capacity, taking care to prevent entrainment or solu- Winkler Method, the Alsterberg (Azide) Procedure, the Rideal-
tion of atmospheric oxygen. Stewart (permanganate) modification, and the Pomeroy-
6.3 With water under pressure, connect a tube of inert Kirshman-Alsterberg modification.
material to the inlet and extend the tube outlet to the bottom of 8.3 The precision of the test method was carried out using a
the sample bottle. Use stainless steel, Type 304 or 316, or glass saturated sample of reagent water.
tubing with short neoprene connections. Do not use copper
9. Interferences
tubing, long sections of neoprene tubing, or other types of
polymeric materials. The sample line shall contain a suitable 9.1 Nitrite interferences are eliminated by routine use of
sodium azide. Ferric iron interferes unless 1 mL of potassium
cooling coil if the water being sampled is above room
temperature, in which case cool the sample 16 to 18°C. When fluoride solution is used, in which case 100 to 200 mg/L can be
tolerated. Ferrous iron interferes, but that interference is
a cooling coil is used, the valve for cooling water adjustment
shall be at the inlet to the cooling coil, and the overflow shall eliminated by the use of potassium permanganate solution.
High levels of organic material or dissolved oxygen can be
be to a point of lower elevation. The valve for adjusting the
accommodated by use of the concentrated iodide-azide solu-
flow of sample shall be at the outlet from the cooling coil. The
tion.
sample flow shall be adjusted to a rate that will fill the sampling
vessel or vessels in 40 to 60 s and flow long enough to provide
10. Apparatus
a minimum of ten changes of water in the sample vessel. If the
10.1 Sample Bottles, 250 or 300 mL capacity with tapered
sampling line is used intermittently, flush the sample line and
ground-glass stoppers. Special bottles with pointed stoppers
cooling coil adequately before using.
and flared mouths are available from supply houses, but regular
6.4 Where samples are collected at varying depths from the
types (tall or low form) are satisfactory.
surface, a special sample bottle holder or weighted sampler
10.2 Pipets, 10-mL capacity, graduated in 0.1-mL divisions
with a removable air tight cover should be used. This unit may
for adding all reagents except sulfuric acid. These pipets
be designed to collect several 250 or 300 mL samples at the
should have elongated tips of approximately 10 mm for adding
same time. Inlet tubes extending to the bottom of each bottle
reagents well below the surface in the sample bottle. Only the
and the water after passing through the sample bottle or bottles
sulfuric acid used in the final step is allowed to run down the
displaces air from the container. When bubbles stop rising from
neck of the bottle into the sample.
the sampler, the unit is filled. Water temperature is measured in
the excess water in the sampler.
11. Reagents
6.5 For depths greater than 2 m, use a Kemmerer-type
11.1 Alkaline Iodide Solutions:
sampler. Bleed the sample from the bottom of the sampler
11.1.1 Alkaline Iodide Solution—Dissolve 500 g of sodium
through a tube extending to the bottom of a 250 to 300 mL
hydroxide or 700 g of potassium hydroxide and 135 g of
biological oxygen demand (BOD) bottle. Fill the bottle to
sodium iodide or 150 g of potassium iodide (KI) in water and
overflowing and prevent turbulence and the formation of
dilute to 1 L. Chemically equivalent potassium and sodium
bubbles while filling the bottle.
salts may be used interchangeably. The solution should not
7. Preservation of Samples
give a color with starch indicator when diluted and acidified.
Store the solution in a dark rubber-stoppered bottle. This
7.1 Do not delay the determination of dissolved oxygen.
solution may be used if nitrite is known to be absent and must
Samples for Test Method A may be preserved 4 to8hby
be used if adjustments are made for ferrous ion interference.
adding 0.7 mL of concentrated sulfuric acid (sp gr 1.84) and
11.1.2 Alkaline Iodide-Sodium Azide Solution I—This solu-
1.0 mL of sodium azide solution (20 g/L) to the bottle
tion may be used in all of these submethods except when
containing the sample in which dissolved oxygen is to be
adjustment is made for ferrous ion. Dissolve 500 g of sodium
determined. Biological activity will be inhibited and the
hydroxide or 700 g of potassium hydroxide and 135 g of
dissolved oxygen retained by storing at the temperature of
sodium iodide or 150 g of potassium iodide in water and dilute
collection or by water sealing (inverting bottle in water) and
to 950 mL. To the cooled solution add 10 g of sodium azide
maintaining at a temperature of 10 to 20°C. Complete the
dissolved in 40 mL of water. Add the NaN solution slowly
determination as soon as possible, using the appropriate 3
with constant stirring. Chemically equivalent potassium and
procedure for determining the concentration of dissolved
sodium salts may be used interchangeably. The solution should
oxygen.
not give a color with starch indicator solution when diluted and
TEST METHOD A—TITRIMETRIC PROCEDURE acidified. Store the solution in a dark rubber-stoppered bottle.
—HIGH LEVEL
11.1.3 Alkaline Iodide-Sodium Azide Solution II—This so-
lution is useful when high concentrations of organic matter are
8. Scope
found or when the dissolved oxygen concentration exceeds 15
8.1 This test method is applicable to waters containing more mg/L. Dissolve 400 g of sodium hydroxide in 500 mL of
than 1000 μg/L of dissolved oxygen such as stream and sewage freshly boiled and cooled water. Cool the water slightly and
samples. It is the user’s responsibility to ensure the validity of dissolve 900 g of sodium iodide. Dissolve 10 g of sodium azide
the test method for waters of untested matrices. in 40 mL of water. Slowly add, with stirring, the azide solution
NOTICE:¬This¬standard¬has¬either¬been¬superceded¬and¬replaced¬by¬a¬new¬version¬or¬discontinued.¬
Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
D 888
to the alkaline iodide solution, bringing the total volume to 1 L. potassium oxalate in 100 mL of water. One millilitre of this
11.2 Manganous Sulfate Solution—Dissolve 364 g of man- solution will reduce 1.1 mL of the KMnO solution. This
ganous sulfate in water, filter, and dilute to 1 L. No more than solution is used in the procedure for eliminating ferrous ion
a trace of iodine should be liberated when the solution is added interference.
to an acidified potassium iodide solution.
11.9 Potassium Permanganate Solution (6.3 g/L)—
11.3 Potassium Biiodate Solution (0.025 N)—Dissolve
Dissolve 6.3 g of potassium permanganate in water and dilute
0.8125 g of potassium biiodate in water and dilute to 1 L in a
to 1 L. With very high ferrous iron concentrations, solution of
volumetric flask.
KMnO should be stronger so that 1 mL will satisfy the
demand. This solution is used in the procedure for eliminating
NOTE 1—If the bottle technique is used, dissolve 1.2188 g of biiodate
ferrous ion interference.
in water and dilute to 1 L to make 0.0375 N.
11.4 Phenylarsine Oxide Solution (0.025 N)—Dissolve
12. Procedure
2.6005 g of phenylarsine oxide in 110 mL of NaOH solution
(12 g/L). Add 800 mL of water to the solution and bring to a 12.1 Elimination of Ferrous Ion Interference, if necessary:
pH of 9.0 by adding HCl (1 + 1). This should require about 2
12.1.1 Add to the sample (collected as in 6.2) 0.70 mL of
mL of HCl. Continue acidification with HCl (1 + 1) until a pH
H SO , followed by 1.0 mL of KMnO solution. Where high
2 4 4
of 6 to 7 is reached, as indicated by a glass-electrode system.
iron is present, also add 1.0 mL of KF solution. Stopper and
Dilute to 1 L. Add 1 mL of chloroform for preservation.
mix by inversion. The acid should be added with a 1-mL pipet
Standardize against potassium biiodate solution.
graduated in 0.1-mL divisions. Add sufficient KMnO solution
to maintain a violet tinge for 5 min. If the color does not persist
NOTE 2—Phenylarsine oxide is more stable than sodium thiosulfate.
for 5 min, add more KMnO solution, but avoid excess. In
However, sodium thiosulfate may be used. The analyst should specify 4
which titrant is used. For a stock solution (0.1 N), dissolve 24.82 g of those cases where more than 5 mL of KMnO solution is
Na S O ·5H O in boiled and cooled water and dilute to 1 L. Preserve by
required, a stronger solution of this reagent may be used to
2 2 3 2
adding 5 mL of chloroform. For a dilute standard titrating solution (0.005
avoid dilution of the sample.
N) transfer 25.00 mL of 0.1 N Na S O to a 500-mL volumetric flask.
2 2 3
12.1.2 After 5 min, completely destroy the permanganate
Dilute to the mark with water and mix completely. Do not prepare more
color by adding 0.5 to 1.0 mL of K C O solution. Mix the
than 12 to 15 h before use. 2 2 4
sample well, and allow it to stand in the dark. Low results are
NOTE 3—If the full bottle technique is used, 3.9007 g must be used to
make 0.0375 N. caused by excess oxalate so it is essential to add only sufficient
NOTE 4—If sodium thiosulfate is used, prepare and preserve a 0.1 N
oxalate to completely decolorize the permanganate without
solution as described in Note 1. Determine the exact normality by titration
having an excess of more than 0.5 mL. Complete decoloriza-
against 0.025 N potassium biiodate solution. Dilute the appropriate
tion should be obtained in
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