ASTM D4655-95

Standard Test Methods for Sulfates in Leather (Total, Neutral, and Combined Acid)

SCOPE
1.1 These test methods are intended for use in determining the total, neutral, and combined acid sulfate in mineral-tanned leather.
1.2 The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 14-May-1995
• Technical Committee: D31 - Leather
• Drafting Committee: D31.06 - Chemical Analysis

Relations

• Replaced By: ASTM D4655-95(2001) - Standard Test Methods for Sulfates in Leather (Total, Neutral, and Combined Acid)
• Effective Date: 15-May-1995
• Referred By: ASTM D4654-87(2020) - Standard Test Method for Sulfate Basicity in Leather
• Effective Date: 15-May-1995

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4655 – 95
Standard Test Methods for
Sulfates in Leather (Total, Neutral, and Combined Acid)
This standard is issued under the fixed designation D 4655; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope methylene blue, both in 95 % alcohol.
1.1 These test methods are intended for use in determining
6. Sampling, Test Specimens, and Test Units
the total, neutral, and combined acid sulfate in mineral-tanned
6.1 The specimen for each determination shall consist of 1
leather.
g leather from the composite sample (See Practice D 2813).
1.2 The values stated in SI units are to be regarded as the
6.2 Two specimens from the composite sample shall be
standard.
tested for each determination.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
7. Procedure
responsibility of the user of this standard to establish appro-
7.1 Total Sulfates—Weigh the specimen to the nearest
priate safety and health practices and determine the applica-
milligram and record the value as W . Transfer the specimen to
bility of regulatory limitations prior to use.
a 250-mL volumetric flask and add 200 mL of 0.1 N ammo-
2. Referenced Documents nium hydroxide or 0.1 molar potassium or sodium dihydrogen
phosphate solution. Immerse the flask up to the neck in a bath
2.1 ASTM Standards:
of boiling water. Thoroughly wet all products by swirling
D 2813 Practice for Sampling Leather for Physical and
2 occasionally. After 2 h cool the flask to room temperature, and
Chemical Tests
2 make up to volume with distilled water, shake, and without
D 4654 Test Method for Sulfate Basicity in Leather
delay filter through a folded filter paper. Discard the first 20 to
3. Significance and Use 25 mL of the filtrate. Pipette 200 mL of the filtrate into a 600
mL beaker and add about 20 mL of 1.5 N hydrochloric acid.
3.1 These test methods are used to determine the basicity of
Heat the solution to boiling and while boiling and stirring the
leather when used in accordance with Test Method D 4654.
solution, add 20 mL of a 1 % solution of barium chloride
4. Apparatus
dropwise. Keep the covered beaker in a warm place at least for
2 h and preferably overnight.
4.1 Volumetric Flask, 250 mL.
7.1.1 Filter the precipitate through a fine grained ashless
4.2 Filter paper, ashless, fine grained and porcelain crucible.
filter paper and wash with hot water until free from chloride. A
4.3 Crucible, Gooch, with porous porcelain filter (optional).
weighed Gooch crucible or a weighed porous crucible may be
5. Reagents
used as an alternative for the filtration. Transfer the paper with
the precipitate to a weighed crucible and ignite gently, either
5.1 Ammonium Hydroxide Solution, (0.1 N)—7 mL/L re-
over a gas burner or in a muffle oven at 900°C for 1 h. Cool the
agent grade concentrate NH OH. Optional: Potassium dihydro-
crucible in a desiccator, weigh, and record the value of the
gen phosphate, 0.1 molar solution (13.6 g/L KH PO)or
2 4
BaSO as W .
sodium dihydrogen phosphate, 0.1 molar solution (13.8 g/ L 4 2
7.2 Neutral Sulfates—Weigh the specimen to the nearest
NaH PO -H O).
2 4 2
milligram and record the value as W . Transfer the specimen to
5.2 Hydrochloric Acid Solution, (1.5 N)—125 mL/L reagent 3
a 250-mL volumetric flask and add 200 mL of distilled water.
grade concentrate hydrochloric acid.
Immerse the flask up to the neck in boiling water. Thoroughly
5.3 Barium Chloride Solution—(BaCl ·2H O), 1 %.
2 2
wet all particles by swirling occasionally. After 2 h cool flask
5.4 Sodium Hydroxide Solution, 0.01 N, 0.4 g/L.
to room temperature, make up to volume with distilled water,
5.5 Mixed Indicator, consisting of 60 mL of a 0.1 %
shake and without delay filter through a folded filter. Discard
solution of methyl red and 40
...