ASTM D2868-07
Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather

Standard No.

ASTM D2868-07

Release Date

2007

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D2868-10

Latest

ASTM D2868-17

Scope

The nitrogen content as determined by this test method is normally considered to be related to the amount of hide substance (protein fiber) present in the leather sample. A factor of 5.62 is normally used to calculate the hide substance from the nitrogen content.

4.1.1 The 5.62 factor represents the average result of many analyses of animal hides, but it cannot be considered to be accurate since it varies somewhat from hide to hide of the same type, from type of hide to type of hide, and also with the thickness of hide retained in the final leather (split thickness as compared to original hide thickness). As a result of these variations, the true factor for any given leather may be expected to vary from 5.44 to 5.80 or about ±3 %.⁴

A given leather sample may contain nitrogenous substances other than hide substance (protein fiber) which will be analyzed for by this test method, such as resins, dyestuffs, etc., that contain nitrogen. Therefore, although this test method is fairly accurate for determining the nitrogen content of leather, its use for determining hide substance may result in large errors.

The hide substance value derived from this determination has a large bearing on other chemical determinations of a given leather. Any errors, such as those described in 4.1.1 and 4.2, will be carried over into these other analytical calculations.

1.1 This test method covers the determination of the nitrogen content of all types of leather. The nitrogen content is used to calculate the hide substance (protein fiber) content of leather.

Note 18212;This test method is essentially a composite of Method 6441 of Federal Test Method Standard No. 311 and Method B 5 of the American Leather Chemists Association.

1.2 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.

ASTM D2868-07 Referenced Document

• ASTM D2813 Standard Practice for Sampling Leather for Physical and Chemical Tests
• ASTM E180 Standard Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals

ASTM D2868-07 history

• 2017 ASTM D2868-17 Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
• 2010 ASTM D2868-10(2015) Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
• 2010 ASTM D2868-10 Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• 2007 ASTM D2868-07 Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• 1996 ASTM D2868-96(2001) Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather
• 1996 ASTM D2868-96 Standard Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather