ASTM D7503-18

Standard Test Method for Measuring the Exchange Complex and Cation Exchange Capacity of Inorganic Fine-Grained Soils

SIGNIFICANCE AND USE
4.1 Fine-grained soils are used in waste containment systems as barriers to flow and contaminant transport. Liquids contained by these barriers can contain ions that may interact with the mineral surfaces in fine-grained soils.  
4.2 The liquid passing through the pores of fine-grained soil can interact with the mineral surface, and affect the physical and chemical characteristics of the soil. This method can be used as part of an evaluation of these interactions.
Note 1: The quality of the result produced by this standard depends on the competence of the personnel performing the test and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors. Practice D3740 provides a means of evaluating some of these factors.
SCOPE
1.1 This test method describes the procedures for measuring the soluble and bound cations as well as the cation exchange capacity (CEC) of fine-grained inorganic soils. Clay minerals in fine-grained soils carry a negative surface charge that is balanced by bound cations near the mineral surface. These bound cations can be exchanged by other cations in the pore water, which are referred to as soluble cations. The cation exchange capacity is a measure of the negative surface charge on the mineral surface. The CEC generally is satisfied by calcium (Ca), sodium (Na), magnesium (Mg), and potassium (K), although other cations may be present depending on the environment in which the soil exists. This test method was developed from concepts described previously in Lavkulich (1981) (1)2 and Rhoades (1982) (2). In soils with appreciable gypsum or calcite, dissolution of these minerals will release Ca in solution that may affect the measurement.  
1.2 In this test method, the soluble salts from the mineral surface are washed off with de-ionized water and then the concentration of soluble salts within the extract is measured. The bound cations of the clay are measured by using a solution containing an index ion that forces the existing cations in the bound layer into solution. The total concentrations of bound and soluble cations in this solution are measured. The CEC is measured by displacing the index ion with another salt solution and measuring the amount of the displaced index ion.  
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.  
1.4 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026. The procedures in Practice D6026 that are used to specify how data are collected, recorded, and calculated are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the objectives of the user. Increasing or reducing the significant digits of reported data to be commensurate with these considerations is common practice. Consideration of the significant digits to be used in analysis methods for engineering design is beyond the scope of this standard.  
1.5 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.  
1.6 This international standard was developed in accordance with internati...

General Information

• Status: Published
• Publication Date: 28-Feb-2018
• ICS: 23.060.10 - Globe valves
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.04 - Hydrologic Properties and Hydraulic Barriers

Relations

• Replaces: ASTM D7503-10 - Standard Test Method for Measuring the Exchange Complex and Cation Exchange Capacity of Inorganic Fine-Grained Soils
• Effective Date: 01-Mar-2018
• Refers: ASTM D4753-24 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-Feb-2024
• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM E145-19 - Standard Specification for Gravity-Convection and Forced-Ventilation Ovens
• Effective Date: 01-Mar-2019
• Refers: ASTM D2216-19 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Mar-2019
• Refers: ASTM D4753-15 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-May-2015
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012
• Refers: ASTM D3740-12 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2012
• Refers: ASTM E145-94(2011) - Standard Specification for Gravity-Convection and Forced-Ventilation Ovens
• Effective Date: 01-Dec-2011
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D3740-11 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Sep-2011
• Refers: ASTM D2216-10 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Jul-2010
• Refers: ASTM D3740-10 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2010

Overview

ASTM D7503-18 is a standardized test method developed by ASTM International for measuring the exchange complex and cation exchange capacity (CEC) of inorganic fine-grained soils. This test method is essential for assessing how fine-grained soils, such as clays, interact with various cations, particularly in applications where these soils serve as barriers to the flow of liquids and the transport of contaminants. Accurate measurement of CEC, as well as the concentrations of bound and soluble cations, provides insight into the soil’s capacity to retain and exchange nutrients and pollutants, which is especially significant in environmental and geotechnical engineering.

Key Topics

• Cation Exchange Capacity (CEC): Refers to the total negative charge on the mineral surface of the soil that is balanced by cations (positively charged ions). Common cations include calcium (Ca), sodium (Na), magnesium (Mg), and potassium (K).
• Bound and Soluble Cations: Bound cations are attached to the mineral surfaces, while soluble cations are present in the soil’s pore water and can freely interact with other ions in solution.
• Exchange Complex: The collection of cations that satisfy the soil’s CEC. Understanding the exchange complex is crucial for evaluating soil chemistry and predicting its interaction with contaminants.
• Test Procedure: Involves washing soluble salts from the soil surface, using an index ion solution to displace and measure bound cations, and determining CEC by quantifying the amount of index ion displaced by a subsequent salt solution.
• Significance for Soil Barriers: Results are particularly critical in waste containment and hydraulic barrier applications, where the retention capacity of clay barriers for various contaminants must be known.

Applications

• Environmental Engineering: Assessing the suitability of fine-grained soils as liners and barriers in landfills or containment systems, ensuring they can effectively retain contaminants and prevent environmental leakage.
• Soil and Agronomy Studies: Suitable for evaluating nutrient retention and release in agricultural soils, guiding the management of soil fertility and remediation strategies.
• Geotechnical Engineering: Used in design, evaluation, and quality control of soil structures and earthworks where cation exchange properties impact long-term soil stability.
• Waste Management: Supports the design of safe sewage and industrial waste containment by characterizing how barrier soils interact with different ionic species present in waste liquids.
• Research and Testing Laboratories: Provides a reliable, standardized approach for laboratories testing soil samples for regulatory compliance, environmental assessments, or academic research.

Related Standards

The following ASTM standards are often referenced together with ASTM D7503-18 for comprehensive testing and quality assurance in soil analysis:

• ASTM D653: Terminology Relating to Soil, Rock, and Contained Fluids
• ASTM D1193: Specification for Reagent Water
• ASTM D2216: Test Methods for Laboratory Determination of Water Content of Soil and Rock
• ASTM D3740: Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock
• ASTM D4753: Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• ASTM D6026: Practice for Using Significant Digits in Geotechnical Data
• ASTM E145: Specification for Ovens Used in Chemical Testing

Practical Value

Using ASTM D7503-18 ensures a consistent, scientifically validated approach for determining the exchange complex and cation exchange capacity of inorganic fine-grained soils. This supports more accurate characterization of soil properties, leading to better engineered barriers, more effective environmental protection, and improved risk management in both civil and environmental engineering projects. The method’s adherence to established international principles guarantees its broad acceptance and reliability.

Keywords: cation exchange capacity, CEC, fine-grained soils, exchange complex, bound cations, soluble cations, ASTM D7503-18, soil testing, environmental engineering, soil barrier, contaminant transport.

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: D7503 − 18
Standard Test Method for
Measuring the Exchange Complex and Cation Exchange
Capacity of Inorganic Fine-Grained Soils
This standard is issued under the fixed designation D7503; 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* specify how data are collected, recorded, and calculated are
regarded as the industry standard. In addition, they are repre-
1.1 This test method describes the procedures for measuring
sentative of the significant digits that should generally be
the soluble and bound cations as well as the cation exchange
retained. The procedures do not consider material variation,
capacity (CEC) of fine-grained inorganic soils. Clay minerals
purpose for obtaining the data, special purpose studies, or any
in fine-grained soils carry a negative surface charge that is
considerations for the objectives of the user. Increasing or
balanced by bound cations near the mineral surface. These
reducing the significant digits of reported data to be commen-
bound cations can be exchanged by other cations in the pore
surate with these considerations is common practice. Consid-
water, which are referred to as soluble cations. The cation
eration of the significant digits to be used in analysis methods
exchange capacity is a measure of the negative surface charge
for engineering design is beyond the scope of this standard.
on the mineral surface. The CEC generally is satisfied by
calcium (Ca), sodium (Na), magnesium (Mg), and potassium 1.5 Units—The values stated in SI units are to be regarded
(K), although other cations may be present depending on the as standard. No other units of measurement are included in this
environment in which the soil exists. This test method was standard. Reporting of test results in units other than SI shall
developed from concepts described previously in Lavkulich not be regarded as nonconformance with this test method.
(1981) (1) and Rhoades (1982) (2). In soils with appreciable
1.6 This international standard was developed in accor-
gypsum or calcite, dissolution of these minerals will release Ca
dance with internationally recognized principles on standard-
in solution that may affect the measurement.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.2 In this test method, the soluble salts from the mineral
mendations issued by the World Trade Organization Technical
surface are washed off with de-ionized water and then the
Barriers to Trade (TBT) Committee.
concentration of soluble salts within the extract is measured.
The bound cations of the clay are measured by using a solution
2. Referenced Documents
containing an index ion that forces the existing cations in the
2.1 ASTM Standards:
bound layer into solution. The total concentrations of bound
D653 Terminology Relating to Soil, Rock, and Contained
and soluble cations in this solution are measured. The CEC is
Fluids
measured by displacing the index ion with another salt solution
D1193 Specification for Reagent Water
and measuring the amount of the displaced index ion.
D2216 Test Methods for Laboratory Determination of Water
1.3 This standard does not purport to address all of the
(Moisture) Content of Soil and Rock by Mass
safety concerns, if any, associated with its use. It is the
D3740 Practice for Minimum Requirements for Agencies
responsibility of the user of this standard to establish appro-
Engaged in Testing and/or Inspection of Soil and Rock as
priate safety, health, and environmental practices and deter-
Used in Engineering Design and Construction
mine the applicability of regulatory limitations prior to use.
D4753 Guide for Evaluating, Selecting, and Specifying Bal-
1.4 All observed and calculated values shall conform to the
ances and Standard Masses for Use in Soil, Rock, and
guide for significant digits and rounding established in Practice
Construction Materials Testing
D6026. The procedures in Practice D6026 that are used to
D6026 Practice for Using Significant Digits in Geotechnical
Data
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
E145 Specification for Gravity-Convection and Forced-
Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic
Ventilation Ovens
Properties and Hydraulic Barriers.
Current edition approved March 1, 2018. Published March 2018. Originally
apporved in 2010. Last previous edition approved in 2010 as D7503–10. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D7503–18. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
*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
D7503 − 18
3. Terminology 5.10 Buchner Funnel, 55 mm or 90 mm diameter, acid
washed (See Fig. 1).
3.1 For definitions of other terms used in this standard, see
Terminology D653. 5.11 Wash Bottle, for dispensing solutions, new or acid
washed.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 acid wash, n—the process of initially rinsing equip- 5.12 Graduated Cylinder, for measuring solution portions,
ment with tap water, followed by a rinse with 10 % HNO acid washed.
solution, and then finally rinsing 3 times with DI water.
5.13 2.5 µm Ashless Filter Paper that covers the surface of
3.2.2 bound cations (BC), n—cations that are adsorbed
Buchner funnel.
(bound) to mineral surfaces that may be exchanged.
5.14 250 mL Volumetric Flasks, class A flask for precision
3.2.3 cation exchange capacity (CEC), n—the total negative
and accuracy.
charge on mineral surface to be satisfied by bound cations.
6. Reagents
3.2.4 exchange complex, n—the collection of bound cations
satisfying the CEC. 6.1 Reagent Water—Use only ASTM Type II water as
defined in Specification D1193.
3.2.5 fine-grained soils, n—any soil with more than 50 %
passing the sieve having an opening size of 0.075 mm.
6.2 Ammonium Acetate, 1M—Dissolve 77.08 g of 99.9 %
pure NH OAc in Type II DI water (See Specification D1193)
3.2.6 inorganic soils, n—any soil with a loss of ignition
andfilltovolumeina1000mLvolumetricflask.AdjustthepH
(LOI) less than 1 %.
of the solution to 7 with ammonium hydroxide or acetic acid.
3.2.7 soluble cations (SC), n—cations in the soil that are not
Approximately 1 L of NH OAc is needed per 6 samples.
bound to the mineral surface.
6.3 Isopropanol—Reagent grade.
4. Significance and Use
6.4 Potassium Chloride, 1M—Dissolve 74.6 g of 99 % pure
KCl in Type II DI water and fill to volume in a 1000 mL
4.1 Fine-grained soils are used in waste containment sys-
volumetric flask. Approximately 1 L of KCl is needed per 6
tems as barriers to flow and contaminant transport. Liquids
samples.
contained by these barriers can contain ions that may interact
with the mineral surfaces in fine-grained soils.
6.5 Ammonium Sulfate—Dry 238 mg of ACS Certified
(NH ) SO for4hat40°C. Make a 200 mg/L stock solution
4.2 The liquid passing through the pores of fine-grained soil
4 2 4
by dissolving the dried compound in 100 mL of Type II DI
can interact with the mineral surface, and affect the physical
water and fill to volume in a 250 mL volumetric flask. Prepare
and chemical characteristics of the soil. This method can be
calibration standards by diluting the stock solution into con-
used as part of an evaluation of these interactions.
centrations of 10, 20, 40, 50, and 80 mg/L.
NOTE1—Thequalityoftheresultproducedbythisstandarddependson
the competence of the personnel performing the test and the suitability of
6.6 Ca, Mg, K, and Na—Use ICP-grade or AA-grade
the equipment and facilities used. Agencies that meet the criteria of
elementstandardsinanHNO matrixtopreparequalitycontrol
Practice D3740 are generally considered capable of competent and 3
objective testing, sampling, inspection, etc. Users of this standard are
spikes in a NH OAc matrix.
cautioned that compliance with Practice D3740 does not in itself ensure
reliable results. Reliable results depend on many factors. Practice D3740
7. Hazards
provides a means of evaluating some of these factors.
7.1 This standard does not address all of the safety concerns
associated with its use. The user of this standard is responsible
5. Apparatus
for implementing proper safety precautions and should be
5.1 Drying Oven, capable of maintaining a uniform tem-
awareofanypossiblehealthconcernsandrisksrelatedwiththe
perature of 105 6 5 °C that meets the requirements of
materials and chemicals used while following this standard.
Specification E145.
8. Determination of Required Air-Dried Mass of Soil for
5.2 Sieve having an opening of 2.00 mm.
Analysis
5.3 Desiccator, containing silica gel.
8.1 Air-dry approximately 30 g of soil (12 g of solid is
5.4 Laboratory Balance, 20 g capacity, 60.001 g accuracy
required for testing) according to the procedures described in
and precision selected in accordance with Guide D4753.
Test Methods D2216.
5.5 Weighing Paper, or small weighing dish.
8.2 Oven-dry at least2goftheair-dry soil to determine the
5.6 End Over End Shaker, capable of 30 rpm. water content following Test Methods D2216.
5.7 Capped Containers should tightly fit in the end over end 8.3 Determine total mass of air-dry soil needed to have 2 g
shakerholdingcompartmentwithcapacitieslargerthan4
...

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: D7503 − 10 D7503 − 18
Standard Test Method for
Measuring the Exchange Complex and Cation Exchange
Capacity of Inorganic Fine-Grained Soils
This standard is issued under the fixed designation D7503; 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 Scope*
1.1 This test method describes the procedures for measuring the soluble and bound cations as well as the cation exchange
capacity (CEC) of fine-grained inorganic soils. Clay minerals in fine-grained soils carry a negative surface charge that is balanced
by bound cations near the mineral surface. These bound cations can be exchanged by other cations in the pore water, which are
referred to as soluble cations. The cation exchange capacity is a measure of the negative surface charge on the mineral surface.
The CEC generally is satisfied by calcium (Ca), sodium (Na), magnesium (Mg), and potassium (K), although other cations may
be present depending on the environment in which the soil exists. This test method was developed from concepts described
previously in Lavkulich (1981) (1) and Rhoades (1982) (2). In soils with appreciable gypsum or calcite, dissolution of these
minerals will release Ca in solution that may affect the measurement.
1.2 In this test method, the soluble salts from the mineral surface are washed off with de-ionized water and then the
concentration of soluble salts within the extract is measured. The bound cations of the clay are measured by using a solution
containing an index ion that forces the existing cations in the bound layer into solution. The total concentrations of bound and
soluble cations in this solution are measured. The CEC is measured by displacing the index ion with another salt solution and
measuring the amount of the displaced index ion.
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.
1.4 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice
D6026. The procedures in Practice D6026 that are used to specify how data are collected, recorded, and calculated are regarded
as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The
procedures do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for
the objectives of the user. Increasing or reducing the significant digits of reported data to be commensurate with these
considerations is common practice. Consideration of the significant digits to be used in analysis methods for engineering design
is beyond the scope of this standard.
1.5 Units—The values stated in SI units are to be regarded as the standard, unless standard. No other units are specifically
given.of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as
nonconformance with this test method.
1.6 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
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D1193 Specification for Reagent Water
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic Properties
and Hydraulic Barriers.
Current edition approved July 1, 2010March 1, 2018. Published August 2010March 2018. Originally apporved in 2010. Last previous edition approved in 2010 as
D7503–10. DOI: 10.1520/D7503-1010.1520/D7503–18.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
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.
*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
D7503 − 18
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction
Materials Testing
D6026 Practice for Using Significant Digits in Geotechnical Data
E145 Specification for Gravity-Convection and Forced-Ventilation Ovens
3. Terminology
3.1 For definitions of other terms used in this standard, see Terminology D653.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 acid wash, n—the process of initially rinsing equipment with tap water, followed by a rinse with 10 % HNO solution,
and then finally rinsing 3 times with DI water.
3.2.2 bound cations (BC), n—cations that are adsorbed (bound) to mineral surfaces that may be exchanged.
3.2.3 cation exchange capacity (CEC), n—the total negative charge on mineral surface to be satisfied by bound cations.
3.2.4 exchange complex, n—the collection of bound cations satisfying the CEC.
3.2.5 fine-grained soils, n—any soil with more than 50 % passing the No. 200 US standard sieve.sieve having an opening size
of 0.075 mm.
3.2.6 inorganic soils, n—any soil with a loss of ignition (LOI) less than 1 %.
3.2.7 soluble cations (SC), n—cations in the soil that are not bound to the mineral surface.
4. Significance and Use
4.1 Fine-grained soils are used in waste containment systems as barriers to flow and contaminant transport. Liquids contained
by these barriers can contain ions that may interact with the mineral surfaces in fine-grained soils.
4.2 The liquid passing through the pores of fine-grained soil can interact with the mineral surface, and affect the physical and
chemical characteristics of the soil. This method can be used as part of an evaluation of these interactions.
NOTE 1—The quality of the result produced by this standard depends on the competence of the personnel performing the test and the suitability of the
equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing,
sampling, inspection, etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable
results depend on many factors. Practice D3740 provides a means of evaluating some of these factors.
5. Apparatus
5.1 Drying Oven, capable of maintaining a uniform temperature of 105 6 5 °C that meets the requirements of Specification
E145.
5.2 No. 10 U.S. Standard Sieve having an opening of 2.00 mm.
5.3 Desiccator, containing silica gel.
5.4 Laboratory Balance, 20 g capacity, 60.001 g accuracy and precision.precision selected in accordance with Guide D4753.
5.5 Weighing Paper, or small weighing dish.
5.6 End Over End Shaker, capable of 30 rpm.
5.7 Capped Containers should tightly fit in the end over end shaker holding compartment with capacities larger than 40 mL.
5.8 500 mL Filtering Flask, connectable to low-pressure vacuum line, acid washed (See Fig. 1).
5.9 Flexible Tubing, appropriate size to connect filtering flask to the low-pressure vacuum line (See Fig. 1).
5.10 Buchner Funnel, 55 mm or 90 mm diameter, acid washed (See Fig. 1).
5.11 Wash Bottle, for dispensing solutions, new or acid washed.
5.12 Graduated Cylinder, for measuring solution portions, acid washed.
5.13 2.5 μm Ashless Filter Paper that covers the surface of Buchner funnel.
5.14 250 mL Volumetric Flasks, class A flask for precision and accuracy.
6. Reagents
6.1 Reagent Water: Water—Use only ASTM Type II water as defined in Specification D1193.
D7503 − 18
FIG. 1 Experimental Setup for Vacuum Filtration
6.2 Ammonium Acetate, 1M: 1M—Dissolve 77.08 g of 99.9 % pure NH OAc in Type II DI water (See Specification D1193) and
fill to volume in a 1000 mL volumetric flask. Adjust the pH of the solution to 7 with ammonium hydroxide or acetic acid.
Approximately 1 L of NH OAc is needed per 6 samples.
6.3 Isopropanol: Isopropanol—Reagent grade.
6.4 Potassium Chloride, 1M: 1M—Dissolve 74.6 g of 99 % pure KCl in Type II DI water and fill to volume in a 1000 mL
volumetric flask. Approximately 1 L of KCl is needed per 6 samples.
6.5 Ammonium Sulfate: Sulfate—Dry 238 mg of ACS Certified (NH ) SO for 4 h at 40 °C. Make a 200 mg/L stock solution
4 2 4
by dissolving the dried compound in 100 mL of Type II DI water and fill to volume in a 250 mL volumetric flask. Prepare
calibration standards by diluting the stock solution into concentrations of 10, 20, 40, 50, and 80 mg/L.
6.6 Ca, Mg, K, and Na: Na—Use ICP-grade or AA-grade element standards in an HNO matrix to prepare quality control spikes
in a NH OAc matrix.
7. Hazards
7.1 This standard does not address all of the safety concerns associated with its use. The user of this standard is responsible for
implementing proper safety precautions and should be aware of any possible health concerns and risks related with the materials
and chemicals used while following t
...