ASTM D5257-11
(Test Method)Standard Test Method for Dissolved Hexavalent Chromium in Water by Ion Chromatography
Standard Test Method for Dissolved Hexavalent Chromium in Water by Ion Chromatography
SIGNIFICANCE AND USE
Hexavalent chromium salts are used extensively in the metal finishing and plating industries, in the leather industry as a tanning agent, and in the manufacture of paints, dyes, explosives, and ceramics. Trivalent chromium salts are used as mordants in textile dying, in the ceramic and glass industry, and in photography. Chromium, in either oxidation state, may be present in wastewater from these industries and may also be discharged from chromate-treated cooling waters.
Hexavalent chromium is toxic to humans, animals, and aquatic life. It can produce lung tumors when inhaled and readily induces skin sensitization. It is not known whether cancer will result from ingestion of chromium in any of its valence states.
Ion chromatography provides a means of separating the hexavalent chromium from other species present in the sample, many of which interfere with other detection methods. The combination of this separation with a sensitive colorimetric detection method provides a selective and sensitive analytical method for hexavalent chromium with minimal sample preparation.
SCOPE
1.1 This test method covers procedures for the determination of dissolved hexavalent chromium in wastewater, surface water, and drinking water.
1.2 The precision and bias of this test method has been tested in reagent water and industrial wastewater and has been found suitable over the range of approximately 1 to 1000 μg/L. See Table 1 for details. Higher levels can be determined by appropriate dilution.
1.3 Samples containing very high levels of anionic species (that is, chloride, sulfate, etc.) may cause column overload. Samples containing high levels of reducing species (that is, sulfides, sulfites, etc.) may cause reduction of Cr(VI) to Cr(III). This can be minimized by buffering the sample to a pH of 9 to 9.5, filtering it, storing it at 6°C. aA holding time of 28 days may be used if the user can demonstrate that such holding time does not affect sample integrity per US EPA 40 CFR 136 Part II.
1.4 The values stated in either SI or inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
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.
General Information
Relations
Buy Standard
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: D5257 − 11
Standard Test Method for
Dissolved Hexavalent Chromium in Water by Ion
1
Chromatography
This standard is issued under the fixed designation D5257; 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* D1193 Specification for Reagent Water
D2777 Practice for Determination of Precision and Bias of
1.1 This test method covers procedures for the determina-
Applicable Test Methods of Committee D19 on Water
tion of dissolved hexavalent chromium in wastewater, surface
D3370 Practices for Sampling Water from Closed Conduits
water, and drinking water.
D5810 Guide for Spiking into Aqueous Samples
1.2 The precision and bias of this test method has been
D5847 Practice for Writing Quality Control Specifications
tested in reagent water and industrial wastewater and has been
for Standard Test Methods for Water Analysis
found suitable over the range of approximately 1 to 1000 µg/L.
2.2 EPA Standard:
See Table 1 for details. Higher levels can be determined by
EPA Method 218.6 Determination of Dissolved Hexavalent
appropriate dilution.
Chromium in DrinkingWater, Groundwater and Industrial
3
1.3 Samples containing very high levels of anionic species Wastewater Effluents by Ion Chromatography
(that is, chloride, sulfate, etc.) may cause column overload. US EPA 40 CFR 136
Samples containing high levels of reducing species (that is,
3. Terminology
sulfides,sulfites,etc.)maycausereductionofCr(VI)toCr(III).
This can be minimized by buffering the sample to a pH of 9 to
3.1 Definitions—For definitions of terms used in this test
9.5, filtering it, storing it at <6°C. aA holding time of 28 days
method, refer to Terminology D1129.
may be used if the user can demonstrate that such holding time
3.2 Definitions of Terms Specific to This Standard:
does not affect sample integrity per US EPA 40 CFR 136 Part
3.2.1 eluent—the ionic mobile phase used to transport the
II.
sample through the ion-exchange column.
1.4 The values stated in either SI or inch-pound units are to
3.2.2 resolution—the ability of a column to separate con-
be regarded as the standard. The values given in parentheses
stituents under specified test conditions.
are for information only.
4. Summary of Test Method
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Afixedvolumeofbufferedandfilteredsample,typically
responsibility of the user of this standard to establish appro-
100 µL, is injected into the eluent flow path and separated by
priate safety and health practices and determine the applica-
anion exchange using an ammonium sulfate based eluent.
bility of regulatory limitations prior to use.
4.2 After separation, the sample is reacted with an acidic
solution of diphenylcarbohydrazide. Hexavalent chromium
2. Referenced Documents
reacts selectively with this reagent to form the characteristic
2
2.1 ASTM Standards:
violet colored complex.
D1066 Practice for Sampling Steam
4.3 Theeluentstreampassesthroughaphotometricdetector
D1129 Terminology Relating to Water
for detection of the chromium diphenylcarbohydrazide com-
plex by visible absorbance at 530 nm. Absorbance is propor-
tional to the hexavalent chromium concentration.
1
This test method is under the jurisdiction of ASTM Committee D19 on Water
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
5. Significance and Use
in Water.
Current edition approved March 15, 2011. Published April 2011. Originally
5.1 Hexavalent chromium salts are used extensively in the
approved in 1992. Last previous edition approved in 2009 as D5257 – 09. DOI:
metal finishing and plating industries, in the leather industry as
10.1520/D5257-11.
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
3
Standards volume information, refer to the standard’s Document Summary page on Available from Superintendent of Documents, U.S. Government Printing
the ASTM website. Office, Washington, DC 20402.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D5257 − 11
TABLE 1 Determination of Precision and Bias for Hexavalent
6.5 Trace amounts of Cr are sometimes found in reagent
Chromium
grade salts. Since a concentrated buffer solution is used in this
Amount Amount
test method to adjust the pH of samples, reagent blanks should
Water Bias,
A
Added, Found, S S
t
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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:D5257–03 Designation:D5257–11
Standard Test Method for
Dissolved Hexavalent Chromium in Water by Ion
1
Chromatography
This standard is issued under the fixed designation D5257; 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 procedures for the determination of dissolved hexavalent chromium in wastewater, surface water,
and drinking water.
1.2 The precision and bias of this test method has been tested in reagent water and industrial wastewater and has been found
suitable over the range of approximately 1 to 1000 µg/L. See Table 1 for details. Higher levels can be determined by appropriate
dilution.
1.3Samples containing very high levels of anionic species (that is, chloride, sulfate, etc.) may cause column overload. Samples
containing high levels of reducing species (that is, sulfides, sulfites, etc.) may cause reduction of Cr(VI) to Cr(III). This can be
minimized by buffering the sample to a pH of 9 to 9.5, filtering it, storing it at 4°C and analyzing it within 24 h.
1.4The values stated in SI units are to be regarded as the standard.
1.3 Samples containing very high levels of anionic species (that is, chloride, sulfate, etc.) may cause column overload. Samples
containing high levels of reducing species (that is, sulfides, sulfites, etc.) may cause reduction of Cr(VI) to Cr(III). This can be
minimized by buffering the sample to a pH of 9 to 9.5, filtering it, storing it at <6°C. aA holding time of 28 days may be used
if the user can demonstrate that such holding time does not affect sample integrity per US EPA 40 CFR 136 Part II.
1.4 The values stated in either SI or inch-pound units are to be regarded as the standard. The values given in parentheses are
for information only.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
2
D1066 Practice for Sampling Steam
D1129 Terminology Relating to Water
2
D1192Guide for Equipment for Sampling Water and Steam in Closed Conduits Terminology Relating to Water
2
D1193 Specification for Reagent Water
2
D2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
2
D3370 Practices for Sampling Water from Closed Conduits
2
D5810 Guide for Spiking into Aqueous Samples
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
2.2 EPA Standard:
EPA Method 218.6 Determination of Dissolved Hexavalent Chromium in Drinking Water, Groundwater and Industrial
3
Wastewater Effluents by Ion Chromatography
US EPA 40 CFR 136
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD19onWaterandisthedirectresponsibilityofSubcommitteeD19.05onInorganicConstituentsinWater.
Current edition approved Jan. 10, 2003. Published January 2003. Originally approved in 1992. Last previous edition approved in 1997 as D5257–97. DOI:
10.1520/D5257-03.
Current edition approved March 15, 2011. Published April 2011. Originally approved in 1992. Last previous edition approved in 2009 as D5257 – 09. DOI:
10.1520/D5257-11.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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.
2
Annual Book of ASTM Standards, Vol 11.01.
3
Available from Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
D5257–11
TABLE 1 Determination of Precision and Bias for Hexavalent
Chromium
Amount Amount
Water Bias,
A
Added, Found, S S
t o
Matrix %
µg/L µg/L
Reagent 1.2 1.40 0.16 0.15 + 16.6
1.6 1.87 0.65 . + 16.9
6.0 6.68 1.03 0.53 + 11.3
8.0 8.64 1.10 . + 8.0
16.0 17.4 2.25 0.77 + 8.8
20.0 21.4 2.31 . + 7.0
100 101 1.91 3.76 + 1.0
140 143 5.52 . + 2.1
800 819 24.3 12.7 + 2.4
960 966 18.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.