ASTM D6501-15

Standard Test Method for Phosphonate in Brines

SIGNIFICANCE AND USE
5.1 This test method is useful for the determination of trace level phosphonate residues in brines. Chemical treatment which contain phosphonates are used as mineral scale and corrosion inhibitors in gas and oil drilling and production operations; and other industrial applications. Often, the decision for treatment is based on the ability to measure low phosphonate concentration and not upon performance criteria. Phosphonate concentrations as low as 0.16 mg/L have been shown effective in carbonate scale treatment. This test method enables the measurement of sub-mg/L phosphonate concentration in brines containing interfering elements.  
5.2 The procedure includes measuring total (see 12.3.8) and free orthophosphate (see 12.4.3) ions and the difference in concentration is the phosphonate concentration. The sample could contain orthophosphate naturally, or from decomposition of the phosphonate during processing or well treatment or from treating compounds containing molecular dehydrated phosphates.
SCOPE
1.1 This test method covers the colorimetric determination of phosphonate (PNA) in brines from gas and oil production operations in the range from 0.1 to 5 mg/L.  
1.2 This phosphonate method is intended for use to analyze low concentration of phosphonate in brine containing interfering elements. This test method is most useful for analyzing phosphonate at 0.1 to 1 mg/L range in brines with interfering elements; however, it requires personnel with good analytical skill.  
1.3 This test method has been used successfully with reagent water and both field and synthetic brine. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.  
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. For specific hazard statements, see 9.1.3.

General Information

• Status: Published
• Publication Date: 14-Mar-2015
• ICS: 75.020 - Extraction and processing of petroleum and natural gas
• Technical Committee: D19 - Water
• Drafting Committee: D19.05 - Inorganic Constituents in Water

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: D6501 − 15
Standard Test Method for
1
Phosphonate in Brines
This standard is issued under the fixed designation D6501; 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* D4375 Practice for Basic Statistics in Committee D19 on
Water
1.1 This test method covers the colorimetric determination
D5810 Guide for Spiking into Aqueous Samples
of phosphonate (PNA) in brines from gas and oil production
D5847 Practice for Writing Quality Control Specifications
operations in the range from 0.1 to 5 mg/L.
for Standard Test Methods for Water Analysis
1.2 This phosphonate method is intended for use to analyze
E275 PracticeforDescribingandMeasuringPerformanceof
low concentration of phosphonate in brine containing interfer-
Ultraviolet and Visible Spectrophotometers
ing elements. This test method is most useful for analyzing
3. Terminology
phosphonate at 0.1 to 1 mg/L range in brines with interfering
elements; however, it requires personnel with good analytical
3.1 Definitions—For definitions of terms used in this test
skill.
method, refer to Terminology D1129.
1.3 This test method has been used successfully with
3.2 Definitions of Terms Specific to This Standard:
reagent water and both field and synthetic brine. It is the user’s
3.2.1 phosphonate, n—a group of organophosphorus com-
responsibility to ensure the validity of this test method for
pounds typically used for mineral scale and corrosion control,
waters of untested matrices.
as cleaning agents, dispersants, and chelants.
3.2.1.1 Discussion—Typical phosphonate compounds
1.4 The values stated in SI units are to be regarded as
include, but are not limited to, the following phosphonic acid
standard. No other units of measurement are included in this
and their neutralized salts: Aminotri(methylenephosphonic
standard.
acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenedi-
1.5 This standard does not purport to address all of the
aminetetra (methylenephosphonic acid), hexamethylenedi-
safety concerns, if any, associated with its use. It is the
aminetetra (methylenephosphonic acid), and diethylenetri-
responsibility of the user of this standard to establish appro-
aminepenta (methylenephosphonic acid).
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For specific hazard
4. Summary of Test Method
statements, see 9.1.3.
4.1 Phosphonate materials are converted to orthophosphate
by potassium persulfate digestion. The orthophosphate is then
2. Referenced Documents
reacted with ammonium molybdate to form a phosphomolyb-
2
2.1 ASTM Standards:
date complex.The complex is extracted with a methyl isobutyl
D1129 Terminology Relating to Water
ketone/cyclohexane mixture and measured colorimetrically.
D1193 Specification for Reagent Water
5. Significance and Use
D2777 Practice for Determination of Precision and Bias of
Applicable Test Methods of Committee D19 on Water
5.1 This test method is useful for the determination of trace
D3370 Practices for Sampling Water from Closed Conduits
level phosphonate residues in brines. Chemical treatment
D3856 Guide for Management Systems in Laboratories
which contain phosphonates are used as mineral scale and
Engaged in Analysis of Water
corrosion inhibitors in gas and oil drilling and production
operations; and other industrial applications. Often, the deci-
sion for treatment is based on the ability to measure low
1
This test method is under the jurisdiction of ASTM Committee D19 on Water
phosphonate concentration and not upon performance criteria.
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
in Water.
Phosphonate concentrations as low as 0.16 mg/L have been
Current edition approved March 15, 2015. Published April 2015. Originally
shown effective in carbonate scale treatment. This test method
approved in 1999. Last previous edition approved in 2009 as D6501 – 09. DOI:
enables the measurement of sub-mg/L phosphonate concentra-
10.1520/D6501-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or tion in brines containing interfering elements.
contactASTM Customer Service at [e-mail]. ForAnnual Book ofASTM
5.2 The procedure includes measuring total (see 12.3.8) and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. free orthophosphate (see 12.4.3) ions and the difference in
*A Summary of Changes sectio
...

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: D6501 − 09 D6501 − 15
Standard Test Method for
1
Phosphonate in Brines
This standard is issued under the fixed designation D6501; 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 colorimetric determination of phosphonate (PNA) in brines from gas and oil production
operations in the range from 0.1 to 5 mg/L.
1.2 This phosphonate method is intended for use to analyze low concentration of phosphonate in brine containing interfering
elements. This test method is most useful for analyzing phosphonate at 0.1 to 1 mg/L range in brines with interfering elements;
however, it requires personnel with good analytical skill.
1.3 This test method has been used successfully with reagent water and both field and synthetic brine. It is the user’s
responsibility to ensure the validity of this test method for waters of untested matrices.
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. For specific hazard statements, see 9.1.3.
2. Referenced Documents
2
2.1 ASTM Standards:
D1129 Terminology Relating to Water
D1193 Specification for Reagent Water
D2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
D3370 Practices for Sampling Water from Closed Conduits
D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water
D4375 Practice for Basic Statistics in Committee D19 on Water
D5810 Guide for Spiking into Aqueous Samples
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
E275 Practice for Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 phosphonate, n—a group of organophosphorus compounds typically used for mineral scale and corrosion control, as
cleaning agents, dispersants, and chelants.
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 in Water.
Current edition approved Oct. 1, 2009March 15, 2015. Published October 2009April 2015. Originally approved in 1999. Last previous edition approved in 20042009 as
D6501–04. DOI: 10.1520/D6501-09. – 09. DOI: 10.1520/D6501-15.
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.
3.2.1.1 Discussion—
Typical phosphonate compounds include, but are not limited to, the following phosphonic acid and their neutralized salts:
Aminotri(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic
acid), hexamethylenediaminetetra (methylenephosphonic acid), and diethylenetriaminepenta (methylenephosphonic acid).
*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

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D6501 − 15
4. Summary of Test Method
4.1 Phosphonate materials are converted to orthophosphate by potassium persulfate digestion. The orthophosphate is then
reacted with ammonium molybdate to form a phosphomolybdate complex. The complex is extracted with a methyl isobutyl
ketone/cyclohexane mixture and measured colorimetrically.
5. Significance and Use
5.1 This test method is useful for the determination of trace level phosphonate residues in brines. Chemical treatment which
contain phosphonates are used as mineral scale and corrosion inhibitors in gas and oil drilling and production operations; and other
industrial applications. Often, the decision for treatment is based on the ability to measure low ph
...