ASTM D2807-17a
(Test Method)Standard Test Method for Chromic Oxide in Leather (Perchloric Acid Oxidation)
Standard Test Method for Chromic Oxide in Leather (Perchloric Acid Oxidation)
SIGNIFICANCE AND USE
4.1 The procedure described is specific for chromium in leather. 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 leather itself.
4.2 The chromium content of leather relates to the degree of tannage obtained, and hence may be a matter for specification in the purchase of leather. The procedure described provides adequate accuracy for this purpose.
SCOPE
1.1 This test method covers the determination of chromic oxide in leathers that have been partly or completely tanned with chromium compounds. In general the samples will contain between 1 and 5 % chromium, calculated as chromic oxide.
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. See Section 7 for specific safety hazards.
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.
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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: D2807 − 17a
Standard Test Method for
1
Chromic Oxide in Leather (Perchloric Acid Oxidation)
This standard is issued under the fixed designation D2807; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope D3790 Test Method for Volatile Matter (Moisture) of
Leather by Oven Drying
1.1 This test method covers the determination of chromic
oxide in leathers that have been partly or completely tanned
3. Summary of Test Method
with chromium compounds. In general the samples will con-
3.1 The perchloric acid method is applied to the ash
tain between 1 and 5% chromium, calculated as chromic
oxide. obtained in Test Method D2617. In the acid digestion, any
remaining organic matter is destroyed and the chromium
1.2 The values stated in SI units are to be regarded as
oxidized to the hexavalent state. On dilution, the chromium is
standard. No other units of measurement are included in this
titrated volumetrically with thiosulfate or ferrous salt. The
standard.
perchloric acid method requires less manipulation than proce-
1.3 This standard does not purport to address all of the
dures based on fusion of the ash, but care must be taken
safety concerns, if any, associated with its use. It is the
because of potential hazards in the use of this reagent.
responsibility of the user of this standard to establish appro-
priate safety, health and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 The procedure described is specific for chromium in
See Section 7 for specific safety hazards.
leather. Vanadium is the only common interfering element and
1.4 This international standard was developed in accor-
thisisrarelypresentinquantity.Theprecisionandaccuracyof
dance with internationally recognized principles on standard-
the methods are usually at least as good as the sampling of the
ization established in the Decision on Principles for the
leather itself.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 4.2 Thechromiumcontentofleatherrelatestothedegreeof
Barriers to Trade (TBT) Committee.
tannage obtained, and hence may be a matter for specification
in the purchase of leather. The procedure described provides
2. Referenced Documents
adequate accuracy for this purpose.
2
2.1 ASTM Standards:
5. Apparatus
D2617Test Method for Total Ash in Leather
D2813Practice for Sampling Leather for Physical and
5.1 Potentiometric Titration Equipment—Thisisrequiredin
6+
Chemical Tests
an alternative method for titrating chromium (Cr ) with
D2868Test Method for Nitrogen Content (Kjeldahl) and
ferrousammoniumsulfatesolution.Theequipmentconsistsof:
Hide Substance Content of Leather, Wet Blue and Wet
5.1.1 Stirrer.
White 5.1.2 Calomel and Platinum Electrodes.
D3495Test Method for Hexane Extraction of Leather
5.1.3 Potentiometer—A variety of instruments is satisfac-
3
tory. The most convenient common feature of these instru-
ments is a null-point device (either a cathode-ray electron tube
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD31onLeather
or galvanometer) that will signal the abrupt change occurring
and is the direct responsibility of Subcommittee D31.06 on ChemicalAnalysisThis
in the potential when the end point is reached.
test method was developed in cooperation with the American Leather Chemists
5.1.4 In carrying out the titration, the electrodes are im-
Assn.
Current edition approved Sept. 1, 2017. Published September 2017. Originally mersed in the sample, the solution agitated by the stirrer, and
approved in 1969. Last previous edition approved in 2017 as D2807–17. DOI:
10.1520/D2807-17A.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Satisfactory equipment include, among others the following: the Kelley,
Standards volume information, refer to the standard’s Document Summary page on Serfass,andFishertritrimeters,Leeds&Northruppotentiometers,andBeckmanpH
the ASTM website. meters.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D2807 − 17a
the potential balanced with the galvanometer or cathode-ray 6.5 Perchlo
...
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: D2807 − 17 D2807 − 17a
Standard Test Method for
1
Chromic Oxide in Leather (Perchloric Acid Oxidation)
This standard is issued under the fixed designation D2807; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This test method covers the determination of chromic oxide in leathers that have been partly or completely tanned with
chromium compounds. In general the samples will contain between 1 and 5 % chromium, calculated as chromic oxide.
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 safety, health and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. See Section 7 for specific safety hazards.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
D2617 Test Method for Total Ash in Leather
D2813 Practice for Sampling Leather for Physical and Chemical Tests
D2868 Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
D3495 Test Method for Hexane Extraction of Leather
D3790 Test Method for Volatile Matter (Moisture) of Leather by Oven Drying
3. Summary of Test Method
3.1 The perchloric acid method is applied to the ash obtained in Test Method D2617. In the acid digestion, any remaining
organic matter is destroyed and the chromium oxidized to the hexavalent state. On dilution, the chromium is titrated volumetrically
with thiosulfate or ferrous salt. The perchloric acid method requires less manipulation than procedures based on fusion of the ash,
but care must be taken because of potential hazards in the use of this reagent. The perchloric acid method also tends to give low
results.
4. Significance and Use
4.1 The procedure described is specific for chromium in leather. 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 leather
itself.
4.2 The chromium content of leather relates to the degree of tannage obtained, and hence may be a matter for specification in
the purchase of leather. The procedure described provides adequate accuracy for this purpose.
5. Apparatus
6+
5.1 Potentiometric Titration Equipment—This is required in an alternative method for titrating chromium (Cr ) with ferrous
ammonium sulfate solution. The equipment consists of:
1
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 test
method was developed in cooperation with the American Leather Chemists Assn.
Current edition approved April 1, 2017Sept. 1, 2017. Published May 2017September 2017. Originally approved in 1969. Last previous edition approved in 20152017 as
D2807 – 93 (2015).D2807 – 17. DOI: 10.1520/D2807-17.10.1520/D2807-17A.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D2807 − 17a
5.1.1 Stirrer.
5.1.2 Calomel and Platinum Electrodes.
3
5.1.3 Potentiometer—A variety of instruments is satisfactory. The most convenient common feature of these instruments is a
null-point device (either a cathode-ray electron tube or galvanometer) that will signal the abrupt change occurring in the potential
when the end point is reached.
5.1.4 In carrying out the titration, the electrod
...
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