ASTM D1385-07(2018)e1

Standard Test Method for Hydrazine in Water

SIGNIFICANCE AND USE
5.1 Hydrazine is a man-made chemical and is not found in natural waters. The determination of hydrazine is usually made on boiler feedwaters, process waters, and other waters that have been treated with hydrazine (N2H4) for the purpose of maintaining residuals to prevent corrosion by dissolved oxygen. This reducing chemical reacts with dissolved oxygen to form nitrogen and water. However, under certain conditions it can also decompose to form ammonia and nitrogen. Hydrazine is used extensively as a preboiler treatment chemical for high-pressure boilers to scavenge small amounts of dissolved oxygen that are not removed by mechanical aeration. It has the advantage over sulfite treatment in that it does not produce any dissolved solids in the boiler water. Hydrazine is often determined in concentrations below 0.1 mg/L. However, in layup solutions for the protection of idle boilers, hydrazine may be present in concentrations as high as 200 mg/L.  
5.2 Additionally, hydrazine provides protection where reducing conditions are required, particularly in mixed metallurgy systems for the protection of the copper alloys.  
5.3 Hydrazine is a suspected carcinogen and a threshold limit value in the atmosphere of 1.0 mg/L has been set by OSHA. When in an aqueous solution, hydrazine will oxidize to nitrogen and water in the presence of air over a relatively short period of time.
SCOPE
1.1 This test method covers2 the colorimetric determination of hydrazine in boiler feed waters, condensates, natural, and well waters that have been treated with hydrazine (N2H4). This test method is usable in the range from 5.0 to 200 μg/L (ppb) hydrazine. The range is for photometric measurements made at 458 nm in 50 mm cell. Higher concentrations of hydrazine can also be determined by taking a more diluted sample.  
1.2 It is the users’ responsibility to ensure the validity of this test method for untested types of waters.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 5.3, 8.4, and Footnote 5.  
1.5 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.

General Information

• Status: Published
• Publication Date: 31-Jul-2018
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.03 - Sampling Water and Water-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water

Relations

• Replaces: ASTM D1385-07(2013)e1 - Standard Test Method for Hydrazine in Water
• Effective Date: 01-Aug-2018
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM D1066-18e1 - Standard Practice for Sampling Steam
• Effective Date: 01-Aug-2018
• Refers: ASTM D1066-18 - Standard Practice for Sampling Steam
• Effective Date: 01-Aug-2018
• Refers: ASTM D1066-11 - Standard Practice for Sampling Steam
• Effective Date: 15-Jun-2011
• Refers: ASTM D5810-96(2011) - Standard Guide for Spiking into Aqueous Samples
• Effective Date: 01-May-2011
• Refers: ASTM D3370-10 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Dec-2010
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM E275-08 - Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers
• Effective Date: 15-Oct-2008
• Refers: ASTM D3370-08 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Oct-2008
• Refers: ASTM D3370-07 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Dec-2007
• Refers: ASTM D1066-06 - Standard Practice for Sampling Steam
• Effective Date: 15-Dec-2006
• Refers: ASTM D1129-06ae1 - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1129-06a - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D5810-96(2006) - Standard Guide for Spiking into Aqueous Samples
• Effective Date: 15-Aug-2006

Overview

ASTM D1385-07(2018)e1, titled "Standard Test Method for Hydrazine in Water," is an internationally recognized standard published by ASTM International. This test method establishes a reliable procedure for the colorimetric determination of hydrazine (N₂H₄) in various water sources, including boiler feedwater, condensates, and natural or well waters that have been treated with hydrazine. Hydrazine is commonly used for its oxygen-scavenging properties in high-pressure boiler systems to minimize corrosion. Due to its potency and associated health risks, including its classification as a suspected carcinogen, the accurate measurement of hydrazine levels in water is critical for both operational and safety compliance.

Key Topics

• Significance of Hydrazine Detection

  • Hydrazine is not naturally present in water; its detection is important where it is intentionally added for water treatment.
  • Prevents corrosion by reacting with dissolved oxygen and forming nitrogen and water.
  • Levels must be monitored due to hydrazine’s potential to degrade into ammonia and nitrogen and its carcinogenic properties.

• Testing Scope and Range

  • Suitable for hydrazine concentrations from 5.0 to 200 μg/L (ppb) via photometric measurement at 458 nm using a 50 mm cell.
  • Higher concentrations can be measured through sample dilution.

• Applicability and Limitations

  • The method is primarily intended for treated waters; the user must validate the approach for other water types.
  • No other units besides SI are supported in this standard.

• Safety Considerations

  • Hydrazine poses significant health risks; proper laboratory safety procedures and regulatory compliance are required for handling and testing.

Applications

This hydrazine test method finds its principal applications in:

• Power Generation Facilities

  • Monitoring and controlling hydrazine in boiler feedwater for high-pressure systems to manage corrosive effects due to dissolved oxygen.
  • Used in the lay-up of boilers, where higher hydrazine concentrations (up to 200 mg/L) may be present for long-term system protection.

• Industrial Water Treatment

  • Ensuring correct dosing and residual hydrazine to protect mixed-metal systems, especially those using copper alloys.
  • Comparison with alternative treatments like sulfite, as hydrazine does not contribute to dissolved solids in boiler water.

• Compliance and Safety Assurance

  • Meeting occupational and environmental safety standards, including OSHA guidelines for hydrazine exposure limits (threshold values set at 1.0 mg/L in air).
  • Supporting quality control programs with standardized calibration, verification, and precision assessment of laboratory testing.

• Water Analysis Laboratories

  • Routine monitoring in environments that require accurate low-level hydrazine detection.
  • Validation of analytical protocols across variable water matrices to assure reliable method performance.

Related Standards

The following ASTM standards and guides are typically referenced alongside ASTM D1385 for comprehensive water analysis operations:

• ASTM D1066 - Practice for Sampling Steam
• ASTM D1129 - Terminology Relating to Water
• ASTM D1193 - Specification for Reagent Water
• ASTM D3370 - Practices for Sampling Water from Closed Conduits
• ASTM D5810 - Guide for Spiking into Aqueous Samples
• ASTM D5847 - Practice for Writing Quality Control Specifications for Water Analysis Methods
• ASTM E60 - Practice for Analysis of Metals, Ores, and Related Materials by Spectrophotometry
• ASTM E275 - Practice for Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers

Practical Value

Implementing ASTM D1385-07(2018)e1 ensures:

• Accurate determination of hydrazine concentrations in water systems
• Enhanced protection of industrial equipment from oxidation and corrosion
• Effective hazard management for a chemical of significant regulatory concern
• Standardized methods supporting reliable laboratory practices and regulatory reporting

Keywords: hydrazine, water analysis, ASTM D1385, boiler feedwater, colorimetric determination, photometric measurement, water treatment, corrosion control, industrial water quality, safety compliance.

Standards Content (Sample)

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.
´1
Designation: D1385 − 07 (Reapproved 2018)
Standard Test Method for
Hydrazine in Water
This standard is issued under the fixed designation D1385; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Warning notes were editorially updated throughout and the Keywords section was added in August 2018.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the colorimetric determination
D1066 Practice for Sampling Steam
of hydrazine in boiler feed waters, condensates, natural, and
D1129 Terminology Relating to Water
well waters that have been treated with hydrazine (N H ).This
2 4
D1193 Specification for Reagent Water
test method is usable in the range from 5.0 to 200 µg/L (ppb)
D3370 Practices for Sampling Water from Closed Conduits
hydrazine.The range is for photometric measurements made at
D5810 Guide for Spiking into Aqueous Samples
458 nm in 50 mm cell. Higher concentrations of hydrazine can
D5847 Practice for Writing Quality Control Specifications
also be determined by taking a more diluted sample.
for Standard Test Methods for Water Analysis
1.2 Itistheusers’responsibilitytoensurethevalidityofthis
E60 Practice for Analysis of Metals, Ores, and Related
test method for untested types of waters.
Materials by Spectrophotometry
E275 Practice for Describing and Measuring Performance of
1.3 The values stated in SI units are to be regarded as
Ultraviolet and Visible Spectrophotometers
standard. No other units of measurement are included in this
standard.
3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
3.1.1 For definitions of terms used in this standard, refer to
responsibility of the user of this standard to establish appro-
Terminology D1129.
priate safety, health, and environmental practices and deter-
4. Summary of Test Method
mine the applicability of regulatory limitations prior to use.
For specific precautionary statements, see 5.3, 8.4, and Foot-
4.1 When a solution of p-dimethylaminobenzaldehyde in
note 5.
methyl alcohol and hydrochloric acid is added to hydrazine in
1.5 This international standard was developed in accor- dilutedhydrochloricacidsolution,acharacteristicyellowcolor
dance with internationally recognized principles on standard- of p-dimethylaminobenzalazine is formed. The yellow color
ization established in the Decision on Principles for the formed is proportional to the hydrazine present and is in good
Development of International Standards, Guides and Recom- agreement with Beer’s law in the range from 5.0 to 200 µg/L
mendations issued by the World Trade Organization Technical (ppb) hydrazine.
Barriers to Trade (TBT) Committee.
5. Significance and Use
5.1 Hydrazine is a man-made chemical and is not found in
natural waters.The determination of hydrazine is usually made
This test method is under the jurisdiction of ASTM Committee D19 on Water
on boiler feedwaters, process waters, and other waters that
and is the responsibility of Subcommittee D19.03 on Sampling Water and
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
have been treated with hydrazine (N H ) for the purpose of
2 4
On-Line Water Analysis, and Surveillance of Water
maintaining residuals to prevent corrosion by dissolved oxy-
Current edition approved Aug. 1, 2018. Published September 2018. Originally
gen. This reducing chemical reacts with dissolved oxygen to
approved in 1967. Last previous edition approved in 2013 as D1385 – 07 (2013)ɛ1.
DOI: 10.1520/D1385-07R18E01. form nitrogen and water. However, under certain conditions it
For further information on this test method, the following references may be of
interest:
Watt, G. W., and Chrisp, J. D., “Spectrophotometric Method for the Determination For referenced ASTM standards, visit the ASTM website, www.astm.org, or
of Hydrazine,” Analytical Chemistry, Vol 24, No. 12, 1952, pp. 2006–2008; and contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Wood, P. R., “Determination of Maleic Hydrazide Residues in Plant and Animal Standards volume information, refer to the standard’s Document Summary page on
Tissue,” Analytical Chemistry, Vol 25, No. 12, 1953, pp. 1879–1883. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
D1385 − 07 (2018)
can also decompose to form ammonia and nitrogen. Hydrazine 8.2 Purity of Water—Unless otherwise indicated, references
is used extensively as a preboiler treatment chemical for to water shall be understood to mean reagent water conforming
high-pressure boilers to scavenge small amounts of dissolved to the quantitative requirements of Type III reagent water in
oxygen that are not removed by mechanical aeration. It has the Specification D1193.
advantage over sulfite treatment in that it does not produce any
8.3 Hydrazine Solution, Stock (1.0 mL = 100 µg N H )—
2 4
dissolved solids in the boiler water. Hydrazine is often deter-
Dissolve 0.328 g of hydrazine dihydrochloride (HCl·NH ·
mined in concentrations below 0.1 mg/L. However, in layup
NH ·HCl) in 100 mL of water and 10 mL of HCl (sp gr 1.19).
solutions for the protection of idle boilers, hydrazine may be
Dilute with water to 1 L in a volumetric flask and mix.
present in concentrations as high as 200 mg/L.
(Warning—See 8.4.)
5.2 Additionally, hydrazine provides protection where re-
8.4 Hydrazine Solution, Standard (1.0 mL = 0.500 µg
ducing conditions are required, particularly in mixed metal-
N H )—Dilute 5.0 mL of hydrazine stock solution to 1 L with
2 4
lurgy systems for the protection of the copper alloys.
water and mix. Prepare as needed. (Warning—Hydrazine is a
5.3 Hydrazine is a suspected carcinogen and a threshold suspected carcinogen and should be handled with care. )
limit value in the atmosphere of 1.0 mg/L has been set by
8.5 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
OSHA.When in an aqueous solution, hydrazine will oxidize to
chloric acid (HCl).
nitrogen and water in the presence of air over a relatively short
8.6 p-Dimethylaminobenzaldehyde Solution—Dissolve 4.0
period of time.
g of p-dimethylaminobenzaldehyde [(CH ) NC H CHO] in
3 2 6 4
200 mL of methyl alcohol (CH OH) and 20 mL of HCl (sp gr
6. Interferences
1.19). Store in a dark bottle out of direct sunlight.
6.1 The substances normally present in industrial water do
not interfere with the test; however, the hydrazine content may
9. Sampling
be diminished by oxidizing agents, such as chlorine, bromine,
9.1 Collect the sample in accordance with Practices D3370
and iodine, collected with the sample or absorbed by it prior to
or Practice D1066, whichever is applicable. (Warning—See
testing.
8.4.)
6.2 Colors in the prescribed wavelengths also interfere, as
9.2 Acidifyanddilutethesampleassoonastakenbyadding
do other dark colors or turbidities that cannot be overcome.
1 mLof concentrated HCl (sp gr 1.19) to a 100-mLvolumetric
6.3 Aromatic amines, such as aniline, will also interfere.
flask and then pipetting 50 mLof the sample into the flask and
diluting to 100 mL. Prepare a blank with water at the same
7. Apparatus
time.
7.1 Photometer—Aspectrophotometersuitableformeasure-
9.3 A smaller sample aliquot should be taken if the hydra-
ments at 458 nm and capable of holding cells with a light path
zine concentration is greater than 200 µg/L.
of 50 mm should be used. Filter photometers and photometric
practices prescribed in this test method shall conform to
10. Calibration
Practice E60, and spectrophotometers to Practice E275.
10.1 Prepare a series of standard hydrazine solutions by
7.2 Certain photoelectric filter photometers are capable of
pipetting 0.0, 5.0, 10.0, 25.0, 50.0, 100.0, and 200.0 mL of
measurementat425nm,butnotat458nm.Measurementsmay
hydrazine standard solution (1.0 mL = 0.500 µg N H ) into
2 4
be made at 425 nm with a reduction in sensitivity of approxi-
500-mL volumetric flasks. Add 5 mL of HCl (sp gr 1.19) to
mately 50 % of that possible at 458 nm.
each flask and dilute with water to 500 mL and mix well. This
7.3 Instrumentsthatreadoutindirectconcentrationcanalso will give standard solutions containing 0, 5.0, 10.0, 25.0, 50.0,
be used. Manufacturer’s instructions should be followed. 100, and 200 µg/L (ppb) of hydrazine.
10.2 Pipet 50.0-mL portions of the hydrazine standard
8. Reagents
solutions into clean, dry 100-mLbeakers or flasks and proceed
8.1 Purity of Reagents—Reagent grade chemicals shall be
as directed in 11.2. Plot absorbance on the ordinate and
used in all tests. Unless otherwise indicated, it is intended that
micrograms per litre of hydrazine on the abscissa of linear
all reagents shall conform to the specifications of the Commit-
graph paper. Alternately, graph the data in an electronic
tee onAnalytical Reagents of theAmerican Chemical Society,
spreadsheet or use an instrument that reads out in direct
where such specifications are available. Other grades may be
...