ASTM D3869-95(1999)

Standard Test Methods for Iodide and Bromide Ions in Brackish Water, Seawater, and Brines

SCOPE
1.1 These test methods  cover the determination of soluble iodide and bromide ions, or both, in brackish water, seawater, and brines. Four test methods are given as follows:  
1.1.1 Test Method A for both Iodide and Bromide Ions Volumetric, for concentrations from 0.2 to 2000 mg/L iodide and from 5 to 6500 mg/L bromide (Sections 7 to 14).  
1.1.2 Test Method B for Iodide Ion- Colorimetric, for concentrations from 0.2 to 2000 mg/L iodide (Sections 15 to 23).  
1.1.3 Test Method C for Iodide Ion -Selective electrode, for concentrations from 1 to 2000 mg/L iodide (Sections 24 to 31).  
1.1.4 Test Method D for Bromide Ion- Colorimetric, for concentrations from 40 to 6500 mg/L bromide (Sections 32 to 40).  
1.2 Test Method A is intended for use on all brackish waters, seawaters, and brines that contain appreciable amounts of iodide or bromide ions or both. Test Methods B, C, and D, because of their rapidity and sensitivity, are recommended for the analysis of brackish waters, seawaters, and brines in the field and in the laboratory.  
1.3 Samples containing from 0.2 to 2000 mg/L of iodide or 5 to 6500 mg/L of bromide may be analyzed by these methods.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 19.2 and 36.2.

General Information

• Status: Historical
• Publication Date: 09-Jun-1999
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.05 - Inorganic Constituents in Water

Relations

• Replaced By: ASTM D3869-04 - Standard Test Methods for Iodide and Bromide Ions in Brackish Water, Seawater, and Brines
• Effective Date: 01-Mar-2004

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
An American National Standard
Designation: D 3869 – 95 (Reapproved 1999)
Standard Test Methods for
Iodide and Bromide Ions in Brackish Water, Seawater, and
Brines
This standard is issued under the fixed designation D 3869; 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.
1. Scope bility of regulatory limitations prior to use. For specific
2 precautionary statements, see 19.2 and 36.2.
1.1 These test methods cover the determination of soluble
iodide and bromide ions, or both, in brackish water, seawater,
2. Referenced Documents
and brines. Four test methods are given as follows:
2.1 ASTM Standards:
1.1.1 Test Method A for both Iodide and Bromide Ions—
D 1129 Terminology Relating to Water
Volumetric, for concentrations from 0.2 to 2000 mg/L iodide
D 1193 Specification for Reagent Water
and from 5 to 6500 mg/L bromide (Sections 7-14).
D 2777 Practice for Determination of Precision and Bias of
1.1.2 Test Method B for Iodide Ion—Colorimetric, for
Applicable Methods of Committee D-19 on Water
concentrations from 0.2 to 2000 mg/L iodide (Sections 15-23).
D 3370 Practices for Sampling Water from Closed Con-
1.1.3 Test Method C for Iodide Ion—Selective electrode, for
duits
concentrations from 1 to 2000 mg/L iodide (Sections 24-31).
E 60 Practice for Photometric and Spectrophotometric
1.1.4 Test Method D for Bromide Ion—Colorimetric, for
Methods for Chemical Analysis of Metals
concentrations from 40 to 6500 mg/L bromide (Sections
E 200 Practice for Preparation, Standardization, and Storage
32-40).
of Standard and Reagent Solutions for Chemical Analysis
1.2 Test Method A is intended for use on all brackish waters,
E 275 Practice for Describing and Measuring Performance
seawaters, and brines that contain appreciable amounts of
of Ultraviolet, Visible, and Near Infrared Spectrophotom-
iodide or bromide ions or both. Test Methods B, C, and D,
eters
because of their rapidity and sensitivity, are recommended for
the analysis of brackish waters, seawaters, and brines in the
3. Terminology
field and in the laboratory.
3.1 Definitions—For definitions of terms used in these test
1.3 Samples containing from 0.2 to 2000 mg/L of iodide or
methods, refer to Terminology D 1129.
5 to 6500 mg/L of bromide may be analyzed by these methods.
1.4 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 Identification of a brackish water, seawater, or brine is
responsibility of the user of this standard to establish appro-
determined by comparison of the concentrations of their
priate safety and health practices and determine the applica-
dissolved constituents. The results are used to evaluate the
origin of the water, determine if it is a possible pollutant or
determine if it is a commercial source of a valuable constituent
such as iodine or bromine.
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
Constituents in Water.
5. Reagents
Current edition approved Sept. 10, 1995. Published November 1995. Originally
5.1 Purity of Reagents—Reagent grade chemicals shall be
published as D 3869 – 79. Last previous edition D 3869 – 94a.
Additional information is contained in the following references: used in all tests. Unless otherwise indicated, it is intended that
Collins, A. G., Geochemistry of Oilfield Waters, Elsevier, New York, N. Y., 1975,
all reagents shall conform to the specification of the Committee
496 pp.
American Petroleum Institute, API Recommended Practice for Analysis of
Oilfield Waters, Subcommittee on Analysis of Oilfield Waters, API RP, 45 2nd ed,
1968, 49 pp. Annual Book of ASTM Standards, Vol 11.01.
Hoke, S. H, Fletcher, G. E., and Collins, A. G., “Fluoride and Iodide Selective Annual Book of ASTM Standards, Vol 03.05.
Electrodes Applied to Oilfield Brine Analysis.” US Department of Energy, Report of Annual Book of ASTM Standards, Vol 15.05.
Investigations, BETC/RI-78/7, 1978. Annual Book of ASTM Standards, Vol 03.06.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 3869 – 95 (1999)
on Analytical Reagents of the American Chemical Society, 11.2 Ammonium Molybdate Solution—Dissolve2gofam-
where such specifications are available. Other grades may be monium molybdate in water and dilute to 100 mL.
used, provided it is first ascertained that the reagent is of 11.3 Bromine Water (Saturated)—Add to 250 mL of water
sufficiently high purity to permit its use without lessening the slightly more liquid bromine (8 to 10 mL) than will dissolve on
accuracy of the determination. shaking. Store in a glass-stoppered amber bottle.
5.2 Purity of Water— Unless otherwise indicated, refer- 11.4 Calcium Carbonate (CaCO ), powdered.
ences to water shall be understood to mean reagent water 11.5 Calcium Oxide (CaO), anhydrous powdered.
conforming to Specification D 1193, Type III. 11.6 Hydrochloric Acid (1 + 1)—Add 1 volume of HCl (sp
gr 1.19) to 1 volume of water.
6. Sampling
11.7 Hydrochloric Acid (1 + 3)—Add 1 volume of HCl (sp
6.1 Collect the sample in accordance with Practices D 3370. gr 1.19) to 3 volumes of water.
11.8 Hydrochloric Acid (1 + 199)—Add 1 volume of HCl
TEST METHOD A—VOLUMETRIC FOR IODIDE
(sp gr 1.19) to 199 volumes of water.
AND BROMIDE
11.9 Methyl Red Indicator Solution (0.1 g/L)—Dissolve
0.01 g of water-soluble methyl red in water and dilute to 100
7. Scope
mL.
7.1 This test method is applicable to brackish waters,
11.10 Potassium Fluoride (KF·2H O)—crystalline.
seawaters, and brines, and is recommended for such waters
11.11 Potassium Iodide (KI), crystals, free of iodates when
containing appreciable amounts of iodide or bromide, or both.
tested in accordance with American Chemical Society (ACS)
The test method can be used for concentrations as high as 2000
specifications.
mg/L iodide and 6500 mg/L bromide.
11.12 Sodium Acetate Solution (275 g/L)—Dissolve 275 g
of sodium acetate trihydrate (NaC H O ·3H O) in water, to
2 3 2 2
8. Summary of Test Method
dilute to 1 L, and filter.
8.1 Iodide in the sample is oxidized with bromine to iodate
11.13 Sodium Chloride (NaCl), crystals, which, in addition
in a buffered solution, the excess bromine is decomposed with
to satisfying ACS specifications, must be free of iodide, iodate,
sodium formate, and the iodate reacts with added iodide to
bromide, and bromate.
form iodine which is titrated with sodium thiosulfate.
11.14 Sodium Formate Solution (500 g/L)—Dissolve 50 g
8.2 Iodide and bromide are oxidized to iodate and bromate,
of sodium formate (NaCHO ) in hot water and dilute to 100
respectively, with hypochlorite. The excess hypochlorite is
mL. This solution must be freshly prepared.
destroyed with sodium formate, leaving iodate and bromate to
11.15 Sodium Hypochlorite Solution—Use a fresh commer-
react with added iodide to liberate iodine which is titrated with
cial sodium hypochlorite or bleach solution containing ap-
sodium thiosulfate.
proximately 5 % NaClO.
8.3 The bromide concentration is calculated by difference
11.16 Sodium Thiosulfate Solution (0.1 N)—Prepare and
between the iodide and combined iodide and bromide deter-
standardize as directed in Practice E 200.
minations.
11.17 Sodium Thiosulfate Solution (0.01 N)—With a cali-
brated pipet transfer 25 mL of the 0.1 N Na S O solution into
2 2 3
9. Interferences
a 250-mL volumetric flask. Dilute to the mark with water that
9.1 Iron, manganese, and organic matter can interfere (Note
has been freshly boiled and cooled then mix well. This solution
1). They are removed by precipitation and filtration. Remaining
shall be prepared not more than 2 days before it is to be used.
traces of iron are masked with fluoride.
11.18 Starch Indicator Solution—Make a paste of6gof
arrowroot or soluble iodometric starch with cold water. Pour
NOTE 1—Brines containing surfactants can cause emulsion problems,
the paste into 1 L of boiling water. Add 20 g of KOH, mix
in which case a suitable emulsion breaker can be used.
thoroughly, and allow to stand for 2 h. Add 6 mL of glacial
10. Apparatus
acetic acid. Mix again and add sufficient HCl (sp gr 1.19) to
adjust the pH to 4.0. Store in a glass-stoppered bottle. Starch
10.1 Mechanical Bottle Shaker.
10.2 Bottles, 200-mL, for use on mechanical shaker. solution prepared in this manner will remain chemically stable
for at least 1 year.
10.3 Pipets.
10.4 Hot-Water Bath, thermostatically controlled to 6 1°C. 11.18.1 If a proprietary starch indicator powder is used, it
shall be so indicated in reporting the results of the analysis.
10.5 Erlenmeyer Flasks, 250-mL.
12. Procedure
11. Reagents
12.1 To remove iron, manganese, and organic matter from
11.1 Acetic Acid, glacial.
the sample, add exactly 100 mL of sample to a bottle. Add 1 g
of calcium oxide, stopper, and place the mixture in a shaker for
1 h. Allow the mixture to stand overnight and filter on a dry
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
folded filter, discarding the first 20 mL that come through.
listed by the American Chemical Society, see Analar Standards for Laboratory
Brines with specific gravities less than 1.009 may be filtered
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
without standing overnight. Prepare a blank in the same
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD. manner.
D 3869 – 95 (1999)
TABLE 1 Determination of Precision and Bias of Iodide Ions,
12.2 Transfer an aliquot of the filtrate containing 1 to 2 mg
Volumetric Methods
of iodide to a 250-mL Erlenmeyer flask. Add sufficient water to
Statistically
provide a total volume of 75 mL.
Amount Added, Amount Significant (95 %
S S 6Bias
12.3 Add 3 drops of methyl red indicator. Add HCl
O T
mg/L Found, mg/L Confidence
(1 + 199) dropwise until the mixture is just slightly acid.
Level)
12.4 Add 10 mL of sodium acetate solution, 1 mL of glacial
12.1 11.4 1 1 −5.78 yes
116.3 112.5 2 3 −3.27 yes
acetic acid, 4 mL of bromine water, and allow to stand for 5
771 743 12 15 +2.63 no
min.
1375 1282 40 73 −6.76 yes
12.5 Add 2 mL of sodium formate solution, blow out any
bromine vapor from the neck of the flask, and wash down the
sides with water.
12.6 When the solution is completely colorless, add 0.2 g of
13.3 Bromide:
KF and 0.5 g of KI. Mix until dissolved and add 15 mL of HCl
C 5 E 2 D
(1 + 1).
12.7 For final treatment and titration of the sample, proceed
CN
as directed in (12.13).
Br , mg/L 5 3 13320 2 X
S
12.8 To determine the combined iodide and bromide, trans-
fer an aliquot of the filtrate (12.1) containing 1 to 2 mg of
where:
bromide to a 250-mL Erlenmeyer flask. Add sufficient water to
−
X = concentration of I as determined above.
make the total volume 75 mL.
12.9 If necessary add sufficient NaCl to produce a 3-g
14. Precision and Bias
chloride content. Add, in order, 10 mL of sodium hypochlorite
solution and approximately 0.4 g of CaCO (or enough so that
14.1 The overall precision (S ) and single-operator preci-
T
approximately 0.1 g will remain after the next step).
sion ( S ) of this test method within their designated ranges
o
12.10 Adjust the pH of the solution with HCl (1 + 3) to a pH
vary with the quantity being tested in accordance with Table 1
between 5.5 and 6.0. Heat at 90°C for 10 min. (A small amount
and Table 2.
of undissolved CaCO should remain at this point.)
14.2 The bias of the test method determined from recoveries
12.11 Remove the flask and cautiously add 10 mL of
of known amounts of iodide and bromide in a series of
sodium formate solution, return the flask to the water bath, and
prepared standards are given in Table 1 and Table 2.
keep the contents hot for 5 min more. Observe the timing
NOTE 2—The precision and bias estimates are based on the interlabo-
closely. Rinse down the inside of the flask with a few millilitres
ratory study on four artificial brine samples containing various amounts of
of water and allow the solution to cool to room temperature.
iodide, bromide, and interfering ions as shown in Table 3. Two analysts in
Do not use a water bath.
each of three laboratories performed duplicate determinations on each of
12.12 Add 3 drops of ammonium molybdate solution, 0.5 g 2 days. Practice D 2777 was used in developing these precision and bias
estimates.
of KF (if iron is present), 0.5 g of KI, mix until dissolved, and
acidify with 15 mL of HCl (1 + 1).
14.3 Precision and bias for this test method conforms to
12.13 Titrate the sample (12.7) for iodide or the sample
Practice D 2777-77, which was in place at the time of
(12.12) for combined iodide and bromide with 0.01 N sodium
collaborative testing. Under the allowances made in 1.5 of
thiosulfate solution using starch indicator. Disregard any return
D2777-86, these precision and bias data do meet existing
of blue color after the endpoint.
requirements for interlaboratory studies of Committee D-19
test methods.
13. Calculation
TEST METHOD B—COLORIMETRIS FOR IODIDE
13.1 Calculate the concentration of iodide and bromide ions
in milligrams per litre as follows:
15. Scope
13.2 Iodide:
15.1 This test method covers the colorimetric determina-
C 5 E 2 D
tion of iodide in brackish water, seawater, and brines where
concentrations range from 0.2 to 2000 mg/L.
where:
C = corrected millilitres of Na S O solution,
2 2 3
16. Summary of Test Method
E = millilitres of Na S O , sample solution, and
2 2 3
16.1 Iodide in the sample is oxidized with nitrous acid and
D = millilitres of Na S O blank solution.
2 2 3
extracted into carbon tetrachloride. The concentration is pro-
CN
I , mg/L 5 3 21150 portional to the intensity of the purple color measured at 517
S
nm.
where:
N = normality of Na S O solution, and
2 2 3
Supporting data are available from ASTM Headquarters. Request RR:D19-
S = millilitres of sample.
1061.
D 3869 – 95 (1999)
TABLE 2 Determination of Precision and Bias of Bromide Ions,
ground in a mortar for a long time. Dissolve 0.3270 g of the KI
Volumetric Method
in water and dilute to exactly 1 L in a volumetric flask.
Amount Statistically
19.5 Potassium Nitrite Solution (100 g KNO /L)—Dissolve
Amount Added, 2
Found, S S 6Bias Significant (95 %
O T
mg/L
10gofKNO in water and dilute to 100 mL.
mg/L Confidence Level
...