ASTM D3230-19

Standard Test Method for Salts in Crude Oil (Electrometric Method)

SIGNIFICANCE AND USE
5.1 This test method is used to determine the approximate chloride content of crude oils, a knowledge of which is important in deciding whether or not the crude oil needs desalting. The efficiency of the process desalter can also be evaluated.  
5.2 Excessive chloride left in the crude oil frequently results in higher corrosion rates in refining units and also has detrimental effects on catalysts used in these units.  
5.3 This test method provides a rapid and convenient means of determining the approximate content of chlorides in crude oil and is useful to crude oil processors.
SCOPE
1.1 This test method covers the determination of the approximate chloride (salts) concentration in crude oil. The range of concentration covered is 3.5 mg/kg to 500 mg/kg or 1.0 lb/1000 bbl to 150 lb/1000 bbl (PTB) as chloride concentration/volume of crude oil.  
1.2 This test method measures conductivity in the crude oil due to the presence of common chlorides, such as sodium, calcium, and magnesium. Other conductive materials may also be present in the crude oil.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3.1 Exception—Acceptable concentration units are g/m3 or PTB (lb/1000 bbl).  
1.4 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. For specific warning statements, see 7.3, 7.4, and 7.11.  
1.5 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.

General Information

• Status: Published
• Publication Date: 30-Apr-2019
• ICS: 75.040 - Crude petroleum
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.03 - Elemental Analysis

Relations

• Refers: ASTM D5002-15 - Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
• Effective Date: 15-Dec-2015
• Refers: ASTM D5002-13 - Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
• Effective Date: 01-Oct-2013
• Refers: ASTM D4928-12 - Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
• Effective Date: 01-Dec-2012
• Refers: ASTM D4928-11 - Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
• Effective Date: 01-Jun-2011
• Refers: ASTM D5002-99(2010) - Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
• Effective Date: 15-Sep-2010
• Refers: ASTM D4928-00(2010) - Standard Test Methods for Water in Crude Oils by Coulometric Karl Fischer Titration
• Effective Date: 01-Jun-2010
• Refers: ASTM D381-09 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 15-Apr-2009
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D5002-99(2005) - Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
• Effective Date: 01-Nov-2005
• Refers: ASTM D4928-00(2005) - Standard Test Methods for Water in Crude Oils by Coulometric Karl Fischer Titration
• Effective Date: 01-Jun-2005
• Refers: ASTM D381-04e1 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 01-Nov-2004
• Refers: ASTM D381-04 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 01-Nov-2004
• Refers: ASTM D381-03 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 10-Jul-2003
• Refers: ASTM D381-01 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 10-Nov-2001
• Refers: ASTM D381-00 - Standard Test Method for Gum Content in Fuels by Jet Evaporation
• Effective Date: 10-Nov-2001

Overview

ASTM D3230-19 is the Standard Test Method for Salts in Crude Oil (Electrometric Method), developed by ASTM International. This standard provides a reliable approach for determining the approximate chloride (salt) content in crude oil over a wide concentration range, using an electrometric (conductivity-based) technique. Knowledge of the salt content in crude oil is pivotal for downstream operations, especially during refining, as it directly impacts corrosion rates and catalyst performance in refineries. Understanding whether crude oil requires desalting, and evaluating the effectiveness of desalter units, forms the core significance of this test.

Key Topics

• Chloride Concentration in Crude Oil: The method covers salt concentration ranges from 3.5 mg/kg to 500 mg/kg (or 1.0 to 150 pounds per 1000 barrels, PTB).
• Electrometric Measurement: The technique measures the conductivity of a crude oil sample dissolved in a mixed alcohol solvent when exposed to an electrical field. Increased conductivity indicates the presence of common inorganic chlorides such as sodium, calcium, and magnesium.
• Calibration and Equipment: The method requires an apparatus capable of applying various voltages to electrodes and measuring the resulting current. Calibration curves are established using standard solutions to relate current measurements to chloride concentrations.
• Reporting Units: Results are typically reported in mg/kg, g/m³, or PTB, with SI units being standard but other units permissible where relevant.
• Quality and Safety: Users must ensure sample homogenization, adhere to reagent specifications, and follow proper safety, health, and environmental protocols.

Applications

ASTM D3230-19 is widely used in the petroleum industry for quality control, process monitoring, and compliance:

• Crude Oil Desalting: Results help determine whether crude oil feedstock requires desalting before further refining, thereby optimizing the operation and maintenance of desalting units.
• Corrosion Control: By quantifying residual salts, refiners can reduce corrosion risks in pipelines, distillation columns, and heat exchangers, extending equipment life.
• Catalyst Protection: The method helps prevent detrimental effects of excessive chlorides on catalysts used in refining processes, ensuring efficient operation and longevity.
• Process Optimization: Quick and convenient measurement allows for real-time monitoring and adjustment during tanker unloading, storage, and blending, promoting efficient refinery workflows.

Related Standards

Professionals referencing ASTM D3230-19 may also consider the following related ASTM petroleum testing standards:

• ASTM D381 - Test Method for Gum Content in Fuels by Jet Evaporation
• ASTM D1193 - Specification for Reagent Water
• ASTM D4928 - Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
• ASTM D5002 - Test Method for Density, Relative Density, and API Gravity of Crude Oils by Digital Density Analyzer

These related benchmarks complement the electrometric method for salt determination, supporting a comprehensive approach to crude oil analysis and quality assurance across the petroleum supply chain.

---

By adhering to ASTM D3230-19, organizations enhance their capability to monitor and control salt content in crude oil, supporting safer and more efficient refining processes while maintaining compliance with international standards for petroleum product testing.

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: D3230 − 19
Standard Test Method for
Salts in Crude Oil (Electrometric Method)
This standard is issued under the fixed designation D3230; 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* D1193 Specification for Reagent Water
D4928 Test Method for Water in Crude Oils by Coulometric
1.1 This test method covers the determination of the
Karl Fischer Titration
approximate chloride (salts) concentration in crude oil. The
D5002 Test Method for Density, Relative Density, and API
range of concentration covered is 3.5 mg⁄kg to 500 mg⁄kg or
Gravity of Crude Oils by Digital Density Analyzer
1.0 lb⁄1000 bbl to 150 lb⁄1000 bbl (PTB) as chloride
concentration/volume of crude oil.
3. Terminology
1.2 This test method measures conductivity in the crude oil
3.1 Definitions of Terms Specific to This Standard:
due to the presence of common chlorides, such as sodium,
3.1.1 PTB—lb/1000 bbl.
calcium, and magnesium. Other conductive materials may also
be present in the crude oil.
3.1.2 salts in crude oil—commonly, chlorides of sodium,
calcium, and magnesium dissolved in crude oil. Other inor-
1.3 The values stated in SI units are to be regarded as
ganic chlorides may also be present.
standard. No other units of measurement are included in this
standard.
4. Summary of Test Method
1.3.1 Exception—Acceptable concentration units are g/m
or PTB (lb/1000 bbl).
4.1 Thistestmethodmeasurestheconductivityofasolution
1.4 This standard does not purport to address all of the
of crude oil in a mixed alcohol solvent when subjected to an
safety concerns, if any, associated with its use. It is the
electrical stress.This test method measures conductivity due to
responsibility of the user of this standard to establish appro-
the presence of inorganic chlorides, and other conductive
priate safety, health, and environmental practices and deter-
material, in the crude oil. A homogenized test specimen is
mine the applicability of regulatory limitations prior to use.
dissolved in a mixed alcohol solvent and placed in a test cell
For specific warning statements, see 7.3, 7.4, and 7.11.
consisting of a beaker and a set of electrodes. A voltage is
1.5 This international standard was developed in accor-
impressed on the electrodes, and the resulting current flow is
dance with internationally recognized principles on standard-
measured. The chloride (salt) content is obtained by reference
ization established in the Decision on Principles for the
to a calibration curve of current versus chloride concentration
Development of International Standards, Guides and Recom-
of known mixtures. Calibration curves are based on standards
mendations issued by the World Trade Organization Technical
prepared to approximate the type and concentration of chlo-
Barriers to Trade (TBT) Committee.
rides in the crude oils being tested.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 This test method is used to determine the approximate
D381 Test Method for Gum Content in Fuels by Jet Evapo-
chloride content of crude oils, a knowledge of which is
ration
important in deciding whether or not the crude oil needs
desalting. The efficiency of the process desalter can also be
This test method is under the jurisdiction of ASTM Committee D02 on
evaluated.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.03 on Elemental Analysis. 5.2 Excessivechlorideleftinthecrudeoilfrequentlyresults
Current edition approved May 1, 2019. Published May 2019. Originally
in higher corrosion rates in refining units and also has
approved in 1973. Last previous edition approved in 2018 as D3230 – 13 (2018).
detrimental effects on catalysts used in these units.
DOI: 10.1520/D3230-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.3 This test method provides a rapid and convenient means
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
of determining the approximate content of chlorides in crude
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. oil and is useful to crude oil processors.
*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
D3230 − 19
NOTE 3—Hexanes solvent is sometimes referred to or sold by other
6. Apparatus
names, such as petroleum naphtha, petroleum ether, ligroine, petroleum
6.1 The apparatus (see AnnexA1) shall consist of a control
benzin, and industrial naphtha. One should confirm that it meets the
unit capable of producing and displaying several voltage levels
requirements of 7.4.
for applying stress to a set of electrodes suspended in a test
7.5 Calcium Chloride (CaCl ) Solution (10 g⁄L)—Transfer
beaker containing a test solution. The apparatus shall be
1.00 g 6 0.01 g of CaCl , or the equivalent weight of a
capable of measuring and displaying the current (mA) con-
hydrated salt, into a 100 mL volumetric flask and dissolve in
ducted through the test solution between the electrodes at each
25 mLof water. Dilute to the mark with mixed alcohol solvent.
voltage level.
7.6 Magnesium Chloride (MgCl ) Solution (10 g ⁄L)—
NOTE 1—Some apparatus are capable of measuring voltage and current
Transfer 1.00 g 6 0.01 g of MgCl , or the equivalent weight of
internally and, after comparison to internal calibration curves, of display-
a hydrated salt, into 100 mL volumetric flask and dissolve in
ing the resultant concentration.
25 mLof water. Dilute to the mark with mixed alcohol solvent.
6.2 Test Beaker—See Annex A1.
7.7 Sodium Chloride (NaCl) Solution (10 g ⁄L)—Transfer
6.3 Pipet, 10 mL (total delivery), shall be used in 10.3 and
1.00 g 6 0.01 g of NaCl into a 100 mL volumetric flask and
11.1 when the viscosity of the crude oil material being
dissolve in 25 mL of water. Dilute to the mark with mixed
analyzed is suitable to transfer the required volume for use in
alcohol solvent.
the test (see 6.3.1). The type of pipet to use is one that is able
7.8 Oil, Refined Neutral—Any refined chloride-free oil of
to be rinsed to ensure the entire volume of the material is
approximately 20 mm /sec (cSt) viscosity at 40 °C and free of
contained in the intended volume.
additive.
6.3.1 In some cases, the viscosity of the crude oil makes it
difficult and impractical to transfer 10 mL of sample using a 7.9 Salts, Mixed Solution (Concentrated Solution)—
pipet. In such cases, it is permissible to use a 10 mLgraduated Combine10.0 mLoftheCaCl solution,20.0 mLoftheMgCl
2 2
cylinder in place of the pipet to transfer the neutral oil (10.3) solution, and 70.0 mL of the NaCl solution, and mix thor-
and crude oil sample (11.1) to ensure consistency. The current oughly.
precision statements are based on the use of 10 mLpipets only.
NOTE 4—The 10:20:70 proportions are representative of the chlorides
present in a number of common crude oils. When the relative proportions
6.4 Cylinders, 100 mL, stoppered.
ofcalcium,magnesium,andsodiumchloridesareknownforagivencrude
6.5 Other volumetric and graduated pipets and volumetric
oil, such proportions should be used for most the accurate results.
flasks.
7.10 Salts, Mixed Solution (Dilute Solution)—Transfer 10
mL of the concentrated mixed chlorides solution into a
7. Reagents and Materials
1000 mL volumetric flask, and dilute to the mark with mixed
7.1 Purity of Reagents—Reagent grade chemicals shall be
alcohol solvent.
used in all tests. Unless otherwise indicated, it is intended that
7.11 Xylene, reagent grade, minimum purity. (Warning—
all reagents shall conform to the specifications of theAmerican
Flammable. Vapor harmful.)
Chemical Society, where such specifications are available.
Other grades may be used, provided it is first ascertained that
8. Sampling
the reagent is of sufficiently high purity to permit its use
8.1 Obtain a sample and test specimen in accordance with
without lessening the accuracy of the determination.
Test Method D4928. Ensure that the sample is completely
7.2 Purity of Water—Unless otherwise indicated, references
homogenized with a suitable mixer. See Test Method D4928
to water shall be understood to mean reagent water as defined
for suitable apparatus and proving.
by Type II in Specification D1193.
8.2 Samples of very viscous materials may be warmed until
7.3 Mixed Alcohol Solvent—Mix 63 volumes of 1-butanol
they are reasonably fluid before they are sampled; however, no
and 37 volumes of absolute methyl alcohol (anhydrous). To
sample shall be heated more than is necessary to lower the
each litre of this mixture, add 3 mL of water. (Warning—
viscosity to a manageable level.
Flammable. Liquid causes eye burns. Vapor harmful. May be
8.3 Samplesofcrudeoilcontainwaterandsedimentandare
fatal or cause blindness if swallowed or inhaled.)
inhomogeneous by nature.The presence of water and sediment
NOTE 2—The mixed alcohol solvent is suitable for use if its conduc-
will influence the conductivity of the sample. The utmost care
tivity is less than 0.25 mA at 125 V ac (or 2 microsiemens). High
shall be taken in obtaining homogenized representative
conductivitycanbeduetoexcesswaterinthesolventandcanindicatethat
the methyl alcohol used is not anhydrous. samples.
7.4 Hexanes, Reagent Grade, (Warning—Extremely
9. Preparation of Apparatus
flammable, harmful if inhaled.)
9.1 Support the apparatus on a level, steady surface, such as
a table.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
9.2 Prepare the apparatus for operation in accordance with
listed by the American Chemical Society, see Annual Standards for Laboratory
the manufacturer’s instructions for calibrating, checking, and
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
operating the equipment. (Warning—The voltage applied to
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. the electrodes can be as great as 250 V ac, and hazardous.)
D3230 − 19
since the electronics are built-in for auto-ranging. Determination of the
9.3 Thoroughly clean and dry all parts of the test beaker, the
blank and the calibration standard responses are the same.
electrodes, and its accessories before starting the test, being
sure to remove any solvent that had been used to clean the 10.5 Repeat the procedure in 10.3, using other volumes of
apparatus. mixed salts solution (dilute solution) as needed to cover the
range of chloride contents of interest.
10. Calibration
10.6 Subtract the value obtained for the blank measurement
10.1 The conductivity of solutions is affected by the tem-
from the indicated current readings of each standard sample,
perature of the specimen when measurements are made. The
and plot the chloride content (ordinate) against net current
temperature of the test specimen at the time of measurement
(mA) readings (abscissa) for each voltage on 3 by 3 cycle
shall be within 3 °C of the temperature at which the calibration
log-log paper, or other suitable format.
curves were made.
NOTE6—Someapparatusarecapableofinternallyrecordingthecurrent
10.2 Establish a blank measurement by following the pro-
readings, standard concentration, and blank, and they provide an output in
cedure in 10.3 and 10.4, omitting the mixed salts solution. direct concentration units. Alternatively, some apparatus are also capable
of internally converting and displaying the measured currents into
Whentheindicatedelectrodecurrentisgreaterthan0.25 mAat
conductivity units of microsiemens, µS, although
...

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: D3230 − 13 (Reapproved 2018) D3230 − 19
Standard Test Method for
Salts in Crude Oil (Electrometric Method)
This standard is issued under the fixed designation D3230; 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 Scope*
1.1 This test method covers the determination of the approximate chloride (salts) concentration in crude oil. The range of
concentration covered is 0 mg3.5 mg ⁄kg to 500 mg ⁄kg or 0 lb1.0 lb ⁄1000 bbl ⁄1000 bbl to 150 lb ⁄1000 bbl ⁄1000 bbl (PTB) as
chloride concentration/volume of crude oil.
1.2 This test method measures conductivity in the crude oil due to the presence of common chlorides, such as sodium, calcium,
and magnesium. Other conductive materials may also be present in the crude oil.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 Exception—Acceptable concentration units are g/m or PTB (lb/1000 bbl).
1.4 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. For specific warning statements, see 7.3, 7.4, and 7.11.
1.5 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:
D381 Test Method for Gum Content in Fuels by Jet Evaporation
D1193 Specification for Reagent Water
D4928 Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
D5002 Test Method for Density, Relative Density, and API Gravity of Crude Oils by Digital Density Analyzer
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 PTB—lb/1000 bbl.
3.1.2 salts in crude oil—commonly, chlorides of sodium, calcium, and magnesium dissolved in crude oil. Other inorganic
chlorides may also be present.
4. Summary of Test Method
4.1 This test method measures the conductivity of a solution of crude oil in a mixed alcohol solvent when subjected to an
electrical stress. This test method measures conductivity due to the presence of inorganic chlorides, and other conductive material,
in the crude oil. A homogenized test specimen is dissolved in a mixed alcohol solvent and placed in a test cell consisting of a beaker
and a set of electrodes. A voltage is impressed on the electrodes, and the resulting current flow is measured. The chloride (salt)
content is obtained by reference to a calibration curve of current versus chloride concentration of known mixtures. Calibration
curves are based on standards prepared to approximate the type and concentration of chlorides in the crude oils being tested.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.03 on Elemental Analysis.
Current edition approved July 1, 2018May 1, 2019. Published August 2018May 2019. Originally approved in 1973. Last previous edition approved in 20132018 as
D3230 – 13.D3230 – 13 (2018). DOI: 10.1520/D3230-13R18.10.1520/D3230-19.
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
D3230 − 19
5. Significance and Use
5.1 This test method is used to determine the approximate chloride content of crude oils, a knowledge of which is important
in deciding whether or not the crude oil needs desalting. The efficiency of the process desalter can also be evaluated.
5.2 Excessive chloride left in the crude oil frequently results in higher corrosion rates in refining units and also has detrimental
effects on catalysts used in these units.
5.3 This test method provides a rapid and convenient means of determining the approximate content of chlorides in crude oil
and is useful to crude oil processors.
6. Apparatus
6.1 The apparatus (see Annex A1) shall consist of a control unit capable of producing and displaying several voltage levels for
applying stress to a set of electrodes suspended in a test beaker containing a test solution. The apparatus shall be capable of
measuring and displaying the current (mA) conducted through the test solution between the electrodes at each voltage level.
NOTE 1—Some apparatus are capable of measuring voltage and current internally and, after comparison to internal calibration curves, of displaying
the resultant concentration.
6.2 Test Beaker—See Annex A1.
6.3 Pipet, 10 mL (total delivery), shall be used in 10.3 and 11.1 when the viscosity of the crude oil material being analyzed is
suitable to transfer the required volume for use in the test (see 6.3.1). The type of pipet to use is one that is able to be rinsed to
ensure the entire volume of the material is contained in the intended volume.
6.3.1 In some cases, the viscosity of the crude oil makes it difficult and impractical to transfer 10 mL of sample using a pipet.
In such cases, it is permissible to use a 10 mL graduated cylinder in place of the pipet to transfer the neutral oil (10.3) and crude
oil sample (11.1) to ensure consistency. The current precision statements are based on the use of 10 mL pipets only.
6.4 Cylinders, 100 mL, stoppered.
6.5 Other volumetric and graduated pipets and volumetric flasks.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the American Chemical Society, where such specifications are available. Other
grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening
the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by
Type II in Specification D1193.
7.3 Mixed Alcohol Solvent—Mix 63 volumes of 1-butanol and 37 volumes of absolute methyl alcohol (anhydrous). To each litre
of this mixture, add 3 mL of water. (Warning—Flammable. Liquid causes eye burns. Vapor harmful. May be fatal or cause
blindness if swallowed or inhaled.)
NOTE 2—The mixed alcohol solvent is suitable for use if its conductivity is less than 0.25 mA at 125 V ac (or 2 microsiemens). High conductivity can
be due to excess water in the solvent and can indicate that the methyl alcohol used is not anhydrous.
7.4 Hexanes, Reagent Grade, (Warning—Extremely flammable, harmful if inhaled.)
NOTE 3—Hexanes solvent is sometimes referred to or sold by other names, such as petroleum naphtha, petroleum ether, ligroine, petroleum benzin,
and industrial naphtha. One should confirm that it meets the requirements of 7.4.
7.5 Calcium Chloride (CaCl ) Solution (10 g ⁄L)—Transfer 1.00 g 6 0.01 g of CaCl , or the equivalent weight of a hydrated salt,
2 2
into a 100 mL volumetric flask and dissolve in 25 mL of water. Dilute to the mark with mixed alcohol solvent.
7.6 Magnesium Chloride (MgCl ) Solution (10 g ⁄L)—Transfer 1.00 g 6 0.01 g of MgCl , or the equivalent weight of a hydrated
2 2
salt, into 100 mL volumetric flask and dissolve in 25 mL of water. Dilute to the mark with mixed alcohol solvent.
7.7 Sodium Chloride (NaCl) Solution (10 g ⁄L)—Transfer 1.00 g 6 0.01 g of NaCl into a 100 mL volumetric flask and dissolve
in 25 mL of water. Dilute to the mark with mixed alcohol solvent.
7.8 Oil, Refined Neutral—Any refined chloride-free oil of approximately 20 mm /sec (cSt) viscosity at 40 °C and free of
additive.
7.9 Salts, Mixed Solution (Concentrated Solution)—Combine 10.0 mL of the CaCl solution, 20.0 mL of the MgCl solution,
2 2
and 70.0 mL of the NaCl solution, and mix thoroughly.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed by
the American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D3230 − 19
NOTE 4—The 10:20:70 proportions are representative of the chlorides present in a number of common crude oils. When the relative proportions of
calcium, magnesium, and sodium chlorides are known for a given crude oil, such proportions should be used for most the accurate results.
7.10 Salts, Mixed Solution (Dilute Solution)—Transfer 10 mL of the concentrated mixed chlorides solution into a 1000 mL
volumetric flask, and dilute to the mark with mixed alcohol solvent.
7.11 Xylene, reagent grade, minimum purity. (Warning—Flammable. Vapor harmful.)
8. Sampling
8.1 Obtain a sample and test specimen in accordance with Test Method D4928. Ensure that the sample is completely
homogenized with a suitable mixer. See Test Method D4928 for suitable apparatus and proving.
8.2 Samples of very viscous materials may be warmed until they are reasonably fluid before they are sampled; however, no
sample shall be heated more than is necessary to lower the viscosity to a manageable level.
8.3 Samples of crude oil contain water and sediment and are inhomogeneous by nature. The presence of water and sediment
will influence the conductivity of the sample. The utmost care shall be taken in obtaining homogenized representative samples.
9. Preparation of Apparatus
9.1 Support the apparatus on a level, steady surface, such as a table.
9.2 Prepare the apparatus for operation in accordance with the manufacturer’s instructions for calibrating, checking, and
operating the equipment. (Warning—The voltage applied to the electrodes can be as great as 250 V ac, and hazardous.)
9.3 Thoroughly clean and dry all parts of the test beaker, the electrodes, and its accessories before starting the test, being sure
to remove any solvent that had been used to clean the apparatus.
10. Calibration
10.1 The conductivity of solutions is affected by the temperature of the specimen when measurements are made. The
temperature of the test specimen at the time of measurement shall be within 3 °C of the temperature at which the calibration curves
were made.
10.2 Establish a blank measurement by following the procedure in 10.3 and 10.4, omitting the mixed salts solution. When the
indicated electrode current is greater than 0.25 mA at 125 V ac, water or another conductive impurity is present and its source must
be found and eliminated before calibration can be completed. Determine a blank measurement each time fresh xylene or mixed
solvent is used.
10.3 Into a dry, 100 mL graduated, glass-stoppered mixing cylinder, add 15 mL of xylene. From a 10 mL pipet (total delivery,
see 6.3), or 10 mL graduated cylinder (see 6.3.1) when applicable, add 10 mL of neutral oil. Rinse the 10 mL pipet or 10 mL
graduated cylinder with xylene until free of oil. Make up to 50 mL with xylene. Stopper and shake the cylinder vigorously for
approximately 60 s to effect solution. Add a quantity of dilute mixed salts solution, in accordance with Table 1, that is appropriate
to the range of salt contents to be measured. Dilute to 100 mL with mixed alcohol solvent. Again shake the cylinder vigorously
for approximately
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