ASTM E649-17a

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E649 − 17 E649 − 17a
Standard Test Method for
Bromine in Chlorine
This standard is issued under the fixed designation E649; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers the determination of bromine in liquid chlorine and in gaseous chlorine with a lower limit of
detection of 4 ug/kg by weight.
1.2 Review the current Safety Data Sheets (SDS) for detailed information concerning toxicity, first-aid procedures, handling,
and safety precautions.
1.3 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. Specific hazard statements are given in Section 7.
1.3 Review the current Safety Data Sheets (SDS) for detailed information concerning toxicity, first-aid procedures, handling,
and safety precautions.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
(Withdrawn 2009)
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
3. Summary of Test Method
3.1 Chlorine gas is sampled by absorption in aqueous sodium hydroxide (NaOH). Liquid chlorine is first vaporized, and the
vapor is absorbed in aqueous sodium hydroxide. An aliquot of the sample solution is reduced with an excess of sulfite ion, acidified,
and excess sulfur dioxide (SO ) boiled out. In a carefully buffered solution, bromide is oxidized to bromate by hypochlorite. Excess
hypochlorite is reduced to chloride by formate. In the presence of molybdate catalyst, bromate is reduced to bromide by iodide,
and the liberated iodine is titrated with standard sodium thiosulfate solution.
4. Significance and Use
4.1 Low levels of bromine contaminant in chlorine cause problems in some industrial uses. This test method may be used to
determine bromine in liquid or gaseous chlorine at levels as low as 4 ug/kg.
5. Apparatus
5.1 The construction of the chlorine gas sampling apparatus and of the assembled sampling equipment is shown in Figs. 1 and
2. Modification of the equipment to deal with special sampling circumstances may be necessary. In Fig. 2, the control valve is
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydrocarbons Aromatic, Industrial, Specialty and Related Chemicals and is the direct
responsibility of Subcommittee D16.16 on Industrial and Specialty Product Standards.
Current edition approved March 1, 2017July 1, 2017. Published March 2017July 2017. Originally approved in 1978. Last previous edition approved in 20112017 as
E649 – 00 (2011).E649 – 17. DOI: 10.1520/E0649-17.10.1520/E0649-17a.
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.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
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E649 − 17a
FIG. 1 Chlorine Gas Sampling Apparatus
1. Inverted liquid chlorine cylinder
2. Chlorine cylinder valve
3. Control valve ( ⁄4-in. 316 stainless steel needle valve)
4. ⁄4-in. PTFE instrument air tubing
5. Small pail or 2-L beaker filled with water
6. Evaporating coil (two loops held with tape at indicated points)
7. Gas sampling apparatus of Fig. 1
FIG. 2 Liquid Chlorine Sampling Equipment
E649 − 17a
shown with an adaptor for connection to a chlorine cylinder valve. Other adaptors will be required when sampling liquid chlorine
in liquefaction plant streams or from large shipping or storage containers.
5.2 A 10-mL buret calibrated in 0.05-mL divisions is used when titrating with 0.01 N standard sodium thiosulfate solution.
6. Reagents
6.1 Purity of Reagents—Unless otherwise indicated, it is intended that all reagents should conform to the specifications of the
Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may
be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy
of the determination.
6.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean Type II or Type III reagent
water conforming to Specification D1193.
6.3 Chloride Solution—Dissolve 200 g of sodium chloride (NaCl) in 940 mL of water.
6.4 Formate Solution—Dissolve 50 g of sodium formate in 175 mL of water.
6.5 Hypochlorite Solution—Dissolve 6.2 g of NaOH in 190 mL of water and chlorinate slowly, with stirring, to give a gain in
weight of 5.0 g.
NOTE 1—If desired, a commercial hypochlorite bleach solution may be used as the hypochlorite solution. Although such commercial bleach solutions
are not made from reagent grade chemicals, the reagent blank determination (see 9.4) corrects for the bromine and any chlorate content in such solutions.
A proprietary 5.25 % sodium hypochlorite bleach solution is satisfactory for this use. Because the sodium chloride and hypochlorite solutions contribute
most to the reagent blanks, dispense these solutions by pipet to ensure uniformity of blanks and determinations (see 9.1 and 9.2).
6.6 Molybdate Solution (44 g/L)—Dissolve 4.4 g of ammonium molybdate (NH ) Mo O ·4H O) in 10 mL of 6 N ammonium
4 6 7 24 2
hydroxide (NH OH) and dilute with 90 mL of water.
6.7 Phenolphthalein Indicator Solution (1 g/L)—Dissolve 0.1 g of phenolphthalein and 0.1 g sodium carbonate (Na CO ) in 5
2 3
mL of water and dilute to 100 mL.
6.8 Phosphate Solution (100 g/L)—Dissolve 50 g of monobasic sodium phosphate (NaH PO ·H O) in 500 mL of water.
2 4 2
6.9 Sodium Hydroxide Solution (10 %)—Dissolve 1 part by weight of sodium hydroxide (NaOH) in 9 parts of water.
6.10 Sodium Thiosulfate, Standard Solution (0.01 N)—Prepare 0.01 N sodium thiosulfate solution fresh daily by accurate
dilution of standard 0.1 N sodium thiosulfate solution. Prepare, standardize, and restandardize 0.1 N sodium thiosulfate solution
in accordance with Practice E200.
6.11 Starch Solution (10 g/L)—Dissolve 1 g of soluble starch in 100 mL of boiling water. Make up fresh daily.
6.12 Sulfuric Acid (6 N)—Add slowly and cautiously with constant stirring, 1 volume of concentrated sulfuric acid (sp gr 1.84,
H SO ) to 5.5 volumes of water. Warning: Use goggles when preparing this solution. Cool to room temperature before use.
2 4
6.13 Sulfuric Acid (1 + 1)—Add slowly with stirring 1 volume of concentrated sulfuric acid (H SO , sp gr 1.84) to 1 volume
2 4
of water. Warning: Use goggles when preparing this solution.
7. Hazards
7.1 Concentrated sulfuric acid, sodium hydroxide, and sodium hypochlorite solutions are rapidly corrosive to skin and eyes. In
case of accidental contact with skin, immediately flush affected part with large volumes of water. For eyes, immediately flush with
water for at least 15 min; then get prompt medical attention. Goggles should be worn when handling these chemicals.
7.2 Chlorine sampling should be performed only by persons thoroughly familiar with handling this material and with operation
of the sampling system. Personnel should be equipped with a respirator, goggles, faceshield, and gloves. If possible, perform
sampling in a hood or other well-ventilated area. In sampling liquid chlorine, do not leave the space between two closed valves
filled with liquid chlorine (see 8.6).
7.3 When sampling and working with chlorine out of doors, people downwind from such operation should be warned of the
possible release of chlorine vapors.
7.4 It is recommended that means be available for disposal of excess chlorine in an environmentally safe and acceptable manner.
If chlorine cannot be disposed of in a chlorine-consuming process, a chlorine absorption system should be provided. When the
analysis and sampling regimen requires an initial purging of chlorine from a container, the purged chlorine should be similarly
handled. Purging to the atmosphere should be avoided.
7.5 In the event chlorine is inhaled, first aid should be summoned immediately and oxygen administered without delay.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
E649 − 17a
7.6 Chlorine is a corrosive and toxic material. A well-ventilated fume hood should be used to house all test equipment when
this product is analyzed in the laboratory.
8. Sampling
8.1 Record to the nearest 0.1 g the tare of the clean and dry chlorine gas sampling apparatus of Fig. 1, except for the insulating
jacket. Add 150 mL of 10 % NaOH solution and seal the stopper firmly in place. Record the tare of this assembly to the nearest
0.1 g. Place the apparatus in the insulating jacket and allow to stand to reach temperature equilibrium.
8.2 Saturated chlorine vapor will contain only about 0.3 as much bromine as the liquid chlorine with which it is in equilibrium.
Hence, when sampling containers of liquid chlorine, it is necessary to make sure that only the liquid phase is sampled. Gaseous
chlorine sources may be samp
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