ASTM D6714-16

Standard Test Method for Chromic Oxide in Ashed Wet Blue (Perchloric Acid Oxidation)

SIGNIFICANCE AND USE
5.1 The procedure described is specific for chromium in Wet Blue. Vanadium is the only common interfering element and this is rarely present in quantity. The precision and accuracy of the methods are usually at least as good as the sampling of the Wet Blue itself, and the accuracy of previously performed test methods.  
5.2 The chromium content of Wet Blue is related to the degree of tannage obtained, and hence may be a matter for specification in the purchase of Wet Blue. The procedure described provides adequate accuracy for this purpose.
SCOPE
1.1 This test method covers the determination of chromic oxide in Wet Blue that has been partly or completely tanned with chromium compounds. In general the samples will contain chromium content between 1 and 5 %, calculated as chromic oxide expressed upon a dry basis otherwise referred to as moisture-free basis (mfb).  
1.2 This test method is specific in that it applies to a sample or samples that are the resultant ash following the execution of Test Method D6716.  
1.3 This test method does not apply to Wet White.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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. Specific hazards are given in Section 8.

General Information

• Status: Historical
• Publication Date: 31-Aug-2016
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.02 - Wet Blue

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6714 − 16
Standard Test Method for
Chromic Oxide in Ashed Wet Blue (Perchloric Acid
1
Oxidation)
This standard is issued under the fixed designation D6714; 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. Terminology
1.1 This test method covers the determination of chromic
3.1 Definitions—The terms and definitions employed within
oxide in Wet Blue that has been partly or completely tanned this test method are commonly used in normal laboratory
with chromium compounds. In general the samples will con-
practice and require no special comment.
tain chromium content between 1 and 5 %, calculated as
chromic oxide expressed upon a dry basis otherwise referred to
4. Summary of Test Method
as moisture-free basis (mfb).
4.1 The perchloric acid method may be applied to the ash
1.2 This test method is specific in that it applies to a sample
obtained in Test Method D6716. The resultant ash is dissolved
or samples that are the resultant ash following the execution of
into acidic solution in a blend of nitric acid and a prepared
Test Method D6716.
oxidation mixture consisting of sulfuric and perchloric acids.
Once completed, oxidation of all trivalent to hexavalent
1.3 This test method does not apply to Wet White.
chromiumisexecutedbycontrolledheating.Upondilution,the
1.4 The values stated in SI units are to be regarded as
chromium is indirectly (back) titrated volumetrically with
standard. No other units of measurement are included in this
standardizedthiosulfateusingreleasediodineasthetitrate.The
standard.
perchloric acid method requires less manipulation than proce-
1.5 This standard does not purport to address all of the
dures based on fusion of the ash. However care must be taken
safety concerns, if any, associated with its use. It is the
because of potential hazards in the use of perchloric acid. The
responsibility of the user of this standard to establish appro-
perchloric acid method also tends to give low results.
priate safety and health practices and determine the applica-
bilityofregulatorylimitationspriortouse.Specifichazardsare
5. Significance and Use
given in Section 8.
5.1 TheproceduredescribedisspecificforchromiuminWet
Blue. Vanadium is the only common interfering element and
2. Referenced Documents
this is rarely present in quantity. The precision and accuracy of
2
2.1 ASTM Standards:
the methods are usually at least as good as the sampling of the
D6658 Test Method for Volatile Matter (Moisture) of Wet
Wet Blue itself, and the accuracy of previously performed test
Blue by Oven Drying
methods.
D6659 Practice for Sampling and Preparation of Wet Blue
5.2 The chromium content of Wet Blue is related to the
and Wet White for Physical and Chemical Tests
degree of tannage obtained, and hence may be a matter for
D6716 Test Method for TotalAsh in Wet Blue or Wet White
specification in the purchase of Wet Blue. The procedure
E180 Practice for Determining the Precision of ASTM
described provides adequate accuracy for this purpose.
Methods for Analysis and Testing of Industrial and Spe-
3
cialty Chemicals (Withdrawn 2009)
6. Apparatus
1
6.1 Analytical Balance, accurate and calibrated to 0.001 g.
This test method is under the jurisdiction ofASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.02 on Wet Blue.
6.2 Erlenmeyer Flasks, 250 mL capacity or equivalent.
Current edition approved Sept. 1, 2016. Published October 2016. Originally
approved in 2001. Last previous edition approved in 2015 as D6714 - 01(2015).
6.3 Burette, 50 mL capacity of suitable calibration grade,
DOI: 10.1520/D6714-16.
2 minimum calibration of 0.1 mL.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.4 Glass Anti-bumping Beads, or equivalent.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
6.5 Measuring Cylinders, 50 mL capacity or equivalent.
3
The last approved version of this historical standard is referenced on
www.astm.org. 6.6 Small Glass Filter Funnel.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6714 − 16
6.7 Dessicator, of suitable size and design and charged with 7.14 Sodium Carbonate—(Na CO ). Used in preparation of
2 3
fresh dessicant. thiosulfate solution.
6.8 Weighing Vessels, of suitable size and design.
7.15 Sodium Thiosulfate—(Na S O ·5H O). Used to pre-
2 2 3 2
pare thiosulfate solution.
6.9 Dryi
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6714 − 01 (Reapproved 2015) D6714 − 16
Standard Test Method for
Chromic Oxide in Ashed Wet Blue (Perchloric Acid
1
Oxidation)
This standard is issued under the fixed designation D6714; 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
1.1 This test method covers the determination of chromic oxide in wet blueWet Blue that has been partly or completely tanned
with chromium compounds. In general the samples will contain chromium content between 1 and 5 %, calculated as chromic oxide
expressed upon a dry basis otherwise referred to as moisture-free basis (mfb).
1.2 This test method is specific in that it applies to a sample or samples that are the resultant ash following the execution of
Test Method D6716.
1.3 This test method does not apply to Wet White.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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. Specific hazards are given in Section 8.
2. Referenced Documents
2
2.1 ASTM Standards:
D6658 Test Method for Volatile Matter (Moisture) of Wet Blue by Oven Drying
D6659 Practice for Sampling and Preparation of Wet Blue and Wet White for Physical and Chemical Tests
D6716 Test Method for Total Ash in Wet Blue or Wet White
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
3
(Withdrawn 2009)
3. Terminology
3.1 Definitions—The terms and definitions employed within this test method are commonly used in normal laboratory practice
and require no special comment.
4. Summary of Test Method
4.1 The perchloric acid method may be applied to the ash obtained in Test Method D6716. The resultant ash is dissolved into
acidic solution in a blend of nitric acid and a prepared oxidation mixture consisting of sulfuric and perchloric acids. Once
completed, oxidation of all trivalent to hexavalent chromium is executed by controlled heating. Upon dilution, the chromium is
indirectly (back) titrated volumetrically with standardized thiosulfate using released iodine as the titrate. The perchloric acid
method requires less manipulation than procedures based on fusion of the ash. However care must be taken because of potential
hazards in the use of perchloric acid. The perchloric acid method also tends to give low results.
5. Significance and Use
5.1 The procedure described is specific for chromium in wet blue.Wet Blue. Vanadium is the only common interfering element
and this is rarely present in quantity. The precision and accuracy of the methods are usually at least as good as the sampling of
the wet blueWet Blue itself, and the accuracy of previously performed test methods.
1
This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.02 on Wet Blue.
Current edition approved Dec. 1, 2015Sept. 1, 2016. Published December 2015October 2016. Originally approved in 2001. Last previous edition approved in 20102015
ɛ
as D6714 - 01(2010)(2015). . DOI: 10.1520/D6714-01R15.10.1520/D6714-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6714 − 16
5.2 The chromium content of wet blueWet Blue is related to the degree of tannage obtained, and hence may be a matter for
specification in the purchase of wet blue.Wet Blue. The procedure described provides adequate accuracy for this purpose.
6. Apparatus
6.1 Analytical Balance, accurate and calibrated to 0.001 g.
6.2 Erlenmeyer Flasks, 250 mL capacity or equivalent.
6.3 Burette, 50 mL capacity of suitable calibration grade, minimum calibration of 0.1 mL.
6.4
...