ASTM D982-16(2022)

Standard Test Method for Organic Nitrogen in Paper and Paperboard

SIGNIFICANCE AND USE
4.1 The purpose of this test method is to determine the amount of organic nitrogen present within a sample of electrical insulation paper or paperboard. Nitrogen content is used to determine if the paper or paperboard has been chemically treated to withstand higher than normal operating temperatures. Such a paper or paperboard is referred to in the industry as “thermally upgraded.” A paper or paperboard that is thermally upgraded can withstand higher operating temperatures and allow the electrical equipment to have a longer useful life span.
SCOPE
1.1 This test method covers the determination of nitrogenous organic materials in paper and paperboard, which typically are used to reduce the thermal degradation of the cellulose in the paper and paperboard.  
1.2 The nitrogen determination by this method does not include the nitrogen in nitro compounds, nitrates, nitrites, azo, hydrazine, cyanide, or pyridine ring-type compounds, none of which are normally found in paper and paperboard. There is no known modification of the method that is applicable to all nitrogenous compounds.  
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 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: 30-Apr-2022
• ICS: 85.060 - Paper and board
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.01 - Electrical Insulating Products

Overview

ASTM D982-16(2022), Standard Test Method for Organic Nitrogen in Paper and Paperboard, is an internationally recognized standard developed by ASTM International. The purpose of this test method is to accurately determine the amount of organic nitrogen in paper and paperboard, particularly those used as electrical insulation materials. Knowing the nitrogen content helps to evaluate whether paper or paperboard has been chemically treated-or “thermally upgraded”-to withstand higher operating temperatures, thereby extending the useful lifespan of electrical equipment.

Key Topics

• Scope of the Standard
  ASTM D982-16(2022) outlines procedures for measuring nitrogenous organic materials in paper and paperboard. These materials are commonly used to reduce the thermal degradation of cellulose, enhancing the material’s heat resistance.

• Exclusions
  The standard’s nitrogen determination method excludes nitro compounds, nitrates, nitrites, azo, hydrazine, cyanide, or pyridine ring-type compounds, as these are not typically found in paper and paperboard.

• Standardized Methodology
  The method described in this standard is a modification of the classic Kjeldahl procedure. It involves digesting the sample with concentrated sulfuric acid and using sodium sulfate to raise the boiling point, while mercuric oxide acts as a catalyst. This digests the organic matter and converts nitrogen to ammonium sulfate, from which the nitrogen content can be determined.

• Units of Measurement
  Results are expressed only in SI units, ensuring consistency and international comparability.

• Compliance with International Principles
  The standard is developed in line with World Trade Organization Technical Barriers to Trade (TBT) Committee principles, supporting global harmonization.

Applications

• Quality Control for Electrical Insulation Papers
  The primary application is in testing electrical insulation paper or paperboard to verify if it meets industry standards for “thermally upgraded” materials. High organic nitrogen content generally indicates chemical treatment for improved thermal stability.

• Materials Testing and Research
  Laboratories and manufacturers in the pulp, paper, and electrical industries use this method for evaluating the quality and suitability of paper-based insulating materials.

• Ensuring Equipment Longevity
  By selecting paper or paperboard with the right level of organic nitrogen, manufacturers of transformers, motors, and other electrical devices can enhance thermal endurance and equipment lifespan.

• Regulatory and Industry Compliance
  Following ASTM D982-16(2022) ensures compliance with both domestic and international regulations concerning the manufacture and use of upgraded paper insulation products.

Related Standards

• ASTM D585 (Withdrawn)
  Practice for Sampling and Accepting a Single Lot of Paper, Paperboard, Fiberboard, and Related Products.

• ASTM D644 (Withdrawn)
  Test Method for Moisture Content of Paper and Paperboard by Oven Drying.

• Technical Association of Pulp and Paper Industry Standard Method T 418 os-61
  Also referenced for similar nitrogen content determinations.

• World Trade Organization TBT Principles
  Internationally recognized guidance that informs the development of this and related standards.

Practical Value

Using ASTM D982-16(2022) ensures consistent, reliable measurement of organic nitrogen in paper and paperboard. This supports manufacturers, testing laboratories, and end-users in selecting materials with enhanced performance characteristics, particularly for thermal stress resistance in electrical insulation applications. By adhering to this standard, organizations demonstrate a commitment to quality, safety, and international best practices in paper and paperboard testing.

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.
Designation: D982 − 16 (Reapproved 2022) Technical Association of Pulp
and Paper Industry
Standard Method T 418 os-61
Standard Test Method for
Organic Nitrogen in Paper and Paperboard
This standard is issued under the fixed designation D982; 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 3. Summary of Test Method
1.1 This test method covers the determination of nitrog- 3.1 This test method is a modification of the well-known
Kjeldahl procedure. In this test method, compounds that yield
enous organic materials in paper and paperboard, which
typically are used to reduce the thermal degradation of the their nitrogen as ammonia are digested with concentrated
sulfuric acid, using sodium sulfate to raise the boiling point,
cellulose in the paper and paperboard.
and mercuric oxide as a catalyst. The organic matter is
1.2 The nitrogen determination by this method does not
destroyed and the nitrogen is fixed as ammonium sulfate in the
include the nitrogen in nitro compounds, nitrates, nitrites, azo,
excess acid.
hydrazine, cyanide, or pyridine ring-type compounds, none of
which are normally found in paper and paperboard.There is no
4. Significance and Use
known modification of the method that is applicable to all
4.1 The purpose of this test method is to determine the
nitrogenous compounds.
amount of organic nitrogen present within a sample of electri-
1.3 The values stated in SI units are to be regarded as
cal insulation paper or paperboard. Nitrogen content is used to
standard. No other units of measurement are included in this
determine if the paper or paperboard has been chemically
standard.
treated to withstand higher than normal operating tempera-
tures. Such a paper or paperboard is referred to in the industry
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard- as “thermally upgraded.” A paper or paperboard that is ther-
mally upgraded can withstand higher operating temperatures
ization established in the Decision on Principles for the
and allow the electrical equipment to have a longer useful life
Development of International Standards, Guides and Recom-
span.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5. Apparatus
2. Referenced Documents
5.1 Kjeldahl Apparatus, with 500 mLor 800 mLflask and a
digestion rack, an efficient bulb or scrubber type of trap to
2.1 ASTM Standards:
ensure that no nonvolatile alkali is carried over, the trap being
D585 Practice for Sampling and Accepting a Single Lot of
connected to the flask with a rubber stopper and to the
Paper, Paperboard, Fiberboard, and Related Product
water-cooled condenser following, with rubber tubing. The
(Withdrawn 2010)
condenser tube shall be made of alkali-resistant glass or block
D644 Test Method for Moisture Content of Paper and
tin with the discharge end connected to a bent glass delivery
Paperboard by Oven Drying (Withdrawn 2010)
tube, the lower end of which is drawn out to a bore of about 3
mm.
This test method is under the jurisdiction of ASTM Committee D09 on 5.2 Other Apparatus—500 mL Erlenmeyer flask, 100 mL
Electrical and Electronic Insulating Materials and is the direct responsibility of
graduatedcylinder,50 mLburet,andmossyzincorglassbeads
Subcommittee D09.01 on Electrical Insulating Products.
for the flask to prevent bumping.
Current edition approved May 1, 2022. Published May 2022. Originally
approved in 1948. Last previous edition approved in 2016 as D982 – 16. DOI:
10.1520/D0982-16R22.
6. Reagents
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.1 Purity of Reagents—Reagent grade chemicals shall be
Standards volume information, refer to the standard’s Document Summary page on
used in all tests. Unless otherwise indicated, it is intended that
the ASTM website.
all reagents shall conform to the specifications of the Commit-
The last approved version of this historical standard is referenced on
www.astm.org. tee onAnalytical Reagents of theAmerican Chemical Society,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D982 − 16 (2022)
where such specifications are available. Other grades are also heat the contents with a small flame or electric heater, taking
acceptable, provided it is first ascertained that the reagent is of care not to apply heat to the flask above the liquid level. An
sufficiently high purity to permit its use without lessening the asbestos-cement board with a hole cut to the proper diameter
accuracy of the determination. fortheflaskissuggested.Atfirstthemixturewillfrothandturn
black. Heat cautiously until frothing has ceased; then increase
6.2 Purity of Water—Unless otherwise indicated, references
the heat until the mixture boils gently. The black color
towatershallbeunderstoodtomeandistilledwaterorwaterof
gradually fades through brown to a colorless or almost color-
equal purity.
less solution. Continue heating for about 1 h after the solution
6.3 Boric Acid and Indicator Solution—Dissolve 43 g of
becomes colorless.
boric acid (H BO ) (free from borax), 6 mL of methyl red
3 3
NOTE3—Tominimizetheinevitableacidcondensationinthehoodwith
indicator, and 4 mL of methylene blue indicator, each 0.1 g in
this procedure, remove most of the acid fumes through a glass tube
100 mL of 95 % ethyl alcohol, per litre of freshly distilled
connected to a water aspirator.
water. Keep the solution in a borosilicate glass bottle. It is
9.2 Allow the solution to cool. It usually will solidify upon
stable for at least 6 months.
cooling to room temperature. When the solution starts to
NOTE 1—An alternative indicator mixture preferred by some for the
solidify or has cooled to room temperature, cautiously add
boric acid solution is 2 mLof methyl red and 10 mLof bromcresol green,
about 300 mL of water and 25 mL of the Na SO solution to
2 4
each 0.1 percent solution, in a 95 % ethanol (1) .
precipitate the mercury. Allow to stand 5 to 10 min with
6.4 Mercuric Oxide, HgO.
occasional shaking.
6.5 Sodium Hydroxide Solution (approximately 50 weight
NOTE 4—It has been reported that mercury sometimes volatilizes and
amalgamates with tin condenser tubes commonly used in the Kjeldahl
percent)—Dissolve 1030 g of sodium hydroxide (NaOH) in 1
apparatus. If the solution is allowed to stand a few minutes after the
L of water.
addition of the Na SO solution, volatilization of the mercury is likely to
2 4
6.6 Sodium Sulfate, anhydrous, powdered Na SO .
be negligible (2).
2 4
9.3 Add 50 mL of the boric acid and indicator solution to a
6.7 Sodium Thiosulfate Solution (80 g/litreL)—Dissolve 80
500 mL Erlenmeyer flask, connect the glass delivery tube to
g of sodium thiosulfate (Na S O ·5H O) in 1 L of water.
2 2 3 2
the discharge end of the condenser, and adjust th
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