ASTM D6016-17(2023)

Standard Test Method for Determination of Nitrogen, Water Extractable in Leather

SIGNIFICANCE AND USE
3.1 This test method provides the means to determine nitrogen containing water extractable materials such as excess and loosely bound tannins, ammonium salts, and nitrates.
SCOPE
1.1 This test method covers quantitatively determining the water extractable nitrogen in leather.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
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: 31-Aug-2023
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.06 - Chemical Analysis

Relations

• Refers: ASTM D3790-17 - Standard Test Method for Volatile Matter (Moisture) of Leather by Oven Drying
• Effective Date: 01-Apr-2017
• Refers: ASTM D2868-17 - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
• Effective Date: 01-Apr-2017
• Refers: ASTM D2868-10(2015) - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
• Effective Date: 01-Dec-2015
• Refers: ASTM D3790-79(2012) - Standard Test Method for Volatile Matter (Moisture) of Leather by Oven Drying
• Effective Date: 01-Apr-2012
• Refers: ASTM D2868-10 - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• Effective Date: 01-Nov-2010
• Refers: ASTM D3495-10 - Standard Test Method for Hexane Extraction of Leather
• Effective Date: 01-Nov-2010
• Refers: ASTM D2876-00(2010) - Standard Test Method for Water-Soluble Matter of Vegetable-Tanned Leather
• Effective Date: 01-Apr-2010
• Refers: ASTM D2868-07 - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• Effective Date: 01-Apr-2007
• Refers: ASTM D3790-79(2006) - Standard Test Method for Volatile Matter (Moisture) of Leather by Oven Drying
• Effective Date: 01-Oct-2006
• Refers: ASTM D3790-79(2006)e1 - Standard Test Method for Volatile Matter (Moisture) of Leather by Oven Drying
• Effective Date: 01-Oct-2006
• Refers: ASTM D2876-00(2005) - Standard Test Method for Water-Soluble Matter of Vegetable-Tanned Leather
• Effective Date: 01-Sep-2005
• Refers: ASTM D2876-00 - Standard Test Method for Water-Soluble Matter of Vegetable-Tanned Leather
• Effective Date: 10-Sep-2000
• Refers: ASTM D3495-00 - Standard Test Method for Hexane Extraction of Leather
• Effective Date: 10-Sep-2000
• Refers: ASTM D2868-96 - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• Effective Date: 10-May-1996
• Refers: ASTM D2868-96(2001) - Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• Effective Date: 10-May-1996

Overview

ASTM D6016-17(2023): Standard Test Method for Determination of Nitrogen, Water Extractable in Leather establishes a quantitative method for measuring the amount of nitrogen that can be extracted by water from leather. This test targets nitrogen present in water extractable materials such as excess and loosely bound tannins, ammonium salts, and nitrates. As an internationally recognized standard developed under the guidelines of the World Trade Organization Technical Barriers to Trade (TBT) Committee, it ensures uniformity and accuracy in the chemical analysis of leather materials.

Key Topics

• Water Extractable Nitrogen in Leather
  The standard specifies procedures to identify and measure nitrogen-containing substances in leather that are soluble in water. Key nitrogen sources include:

  • Loosely bound tannins
  • Ammonium salts
  • Nitrates

• Quantitative Determination
  Results are reported as a percentage on a moisture-free basis, ensuring consistency across different laboratories and testing environments.

• Reference to Related Test Methods

  • Kjeldahl Apparatus: Utilized for nitrogen content determination
  • ASTM D2868: Test method for nitrogen content and hide substance
  • ASTM D3495, D2876, D3790: Methods for hexane extraction, water-soluble matter, and moisture content

• Safety and Compliance
  Users of this standard must consider necessary safety, health, and environmental practices, as the standard does not address all specific risks associated with the method.

Applications

This test method is widely used in the leather industry and associated sectors for:

• Quality Control in Leather Manufacturing

  • Ensures that leather products comply with industry specifications and regulatory requirements regarding residual chemicals.
  • Assesses the effectiveness of tanning and finishing processes by quantifying excess chemicals.

• Environmental and Regulatory Compliance

  • Supports manufacturers in meeting environmental regulations by identifying and limiting potentially hazardous substances in leather goods.

• Research and Development

  • Provides valuable analytical data for product development, especially for optimizing tanning formulas and improving leather performance.

Related Standards

Users of ASTM D6016-17(2023) may also reference or need compliance with related ASTM standards, including:

• ASTM D2868 - Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content
• ASTM D2876 - Test Method for Water-Soluble Matter of Vegetable-Tanned Leather
• ASTM D3495 - Test Method for Hexane Extraction of Leather
• ASTM D3790 - Test Method for Volatile Matter (Moisture) of Leather by Oven Drying

These references provide complementary methods for comprehensive analysis of chemical properties in leather materials.

Practical Value

The ASTM D6016-17(2023) standard offers essential benefits for the global leather industry by:

• Providing a scientifically validated technique to monitor water extractable nitrogen content in leather
• Enhancing product quality, consistency, and reliability in international trade
• Meeting retailer, consumer, and regulatory expectations for safe and compliant leather goods
• Enabling comparative analysis and certification across production sites and markets

By implementing ASTM D6016-17(2023), manufacturers and laboratories strengthen their chemical analysis capability, ensuring that finished leather products are safe, high-quality, and fit for their intended use.

Keywords: ASTM D6016, water extractable nitrogen, leather testing, nitrogen content, chemical analysis, tannins, ammonium salts, nitrates, compliance, quality control, international standards.

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: D6016 − 17 (Reapproved 2023)
Standard Test Method for
Determination of Nitrogen, Water Extractable in Leather
This standard is issued under the fixed designation D6016; 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. Significance and Use
3.1 This test method provides the means to determine
1.1 This test method covers quantitatively determining the
nitrogen containing water extractable materials such as excess
water extractable nitrogen in leather.
and loosely bound tannins, ammonium salts, and nitrates.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this 4. Apparatus
standard.
4.1 Volumetric Flask, 1 L.
1.3 This standard does not purport to address all of the
4.2 Kjeldahl Apparatus, see Test Method D2868.
safety concerns, if any, associated with its use. It is the
5. Reagents
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
5.1 See Test Method D2868.
mine the applicability of regulatory limitations prior to use.
5.2 See Test Method D3495.
1.4 This international standard was developed in accor-
5.3 See Test Method D2876.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
6. Procedure
Development of International Standards, Guides and Recom-
6.1 Follow the procedure for Test Method D3495. Save
mendations issued by the World Trade Organization Technical
extracted leather and follow the procedure in 7.1 only of Test
Barriers to Trade (TBT) Committee.
Method D2876.
6.2 When 1 L has been collected, cool the litre flask with
2. Referenced Documents
contents to room temperature, readjusted up to 1 L with
2.1 ASTM Standards:
distilled water and mixed thoroughly. Transfer 500 mL of the
D2868 Test Method for Nitrogen Content (Kjeldahl) and
solution to an 800 mL Kjeldahl flask. If using automated
Hide Substance Content of Leather, Wet Blue and Wet
Kjeldahl instrumentation, sample size and quantity of reagents
White
may need adjustment. Add 8 g of digestion catalyst (see Test
D2876 Test Method for Water-Soluble Matter of Vegetable-
Method D2868) and 20 mL of sulfuric acid (specific gravity
Tanned Leather 1.83) to the solution and the contents of the flask mixed
thoroughly.
D3495 Test Method for Hexane Extraction of Leather
D3790 Test Method for Volatile Matter (Moisture) of
6.3 Digest the mixture over a low heat source until all
Leather by Oven Drying
organic matter is oxidized as indicated by the end of foaming
and clearing of the solution. When foaming has ceased and the
solution has cleared, apply full heat to the mixture and continue
1 digestion for a minimum of 1 h. After digestion is complete,
This test method is under the jurisdiction of ASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.06 on Chemical Analysis. This
remove the flask from the heat, and a
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