ASTM D3697-17

Standard Test Method for Antimony in Water

SIGNIFICANCE AND USE
5.1 Because of the association with lead and arsenic in industry, it is often difficult to assess the toxicity of antimony and its compounds. In humans, complaints referable to the nervous system have been reported. In assessing human cases, however, the possibility of lead or arsenic poisoning must always be borne in mind. Locally, antimony compounds are irritating to the skin and mucous membranes.  
5.2 ICP-MS may also be appropriate but at a higher instrument cost. See Test Method D5673.
SCOPE
1.1 This test method covers the determination of dissolved and total recoverable antimony in water by atomic absorption spectroscopy.2  
1.2 This test method is applicable in the range from 1 to 15 μg/L of antimony. The range may be extended by less scale expansion or by dilution of the sample.  
1.3 The precision and bias data were obtained on reagent water, tap water, salt water, and two untreated wastewaters. The information on precision and bias may not apply to other waters.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversion to inch-pound units that are provided for information only and are not considered 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.  
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.

General Information

• Status: Published
• Publication Date: 31-May-2017
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.05 - Inorganic Constituents in Water

Relations

• Replaces: ASTM D3697-12 - Standard Test Method for Antimony in Water
• Effective Date: 01-Jun-2017
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM D5673-15 - Standard Test Method for Elements in Water by Inductively Coupled Plasma—Mass Spectrometry
• Effective Date: 01-Jul-2015
• Refers: ASTM D4841-88(2013)e1 - Standard Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents
• Effective Date: 01-Jan-2013
• Refers: ASTM D4841-88(2013) - Standard Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents
• Effective Date: 01-Jan-2013
• Refers: ASTM D2777-12 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jun-2012
• Refers: ASTM D4691-11 - Standard Practice for Measuring Elements in Water by Flame Atomic Absorption Spectrophotometry
• Effective Date: 01-Sep-2011
• Refers: ASTM D5810-96(2011) - Standard Guide for Spiking into Aqueous Samples
• Effective Date: 01-May-2011
• Refers: ASTM D3370-10 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Dec-2010
• Refers: ASTM D5673-10 - Standard Test Method for Elements in Water by Inductively Coupled Plasma-Mass Spectrometry
• Effective Date: 01-Aug-2010
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D3370-08 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Oct-2008
• Refers: ASTM D4841-88(2008) - Standard Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents
• Effective Date: 15-Jul-2008
• Refers: ASTM D2777-08 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jan-2008
• Refers: ASTM D3370-07 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Dec-2007

Overview

ASTM D3697-17: Standard Test Method for Antimony in Water is an internationally recognized method established by ASTM International for the quantitative determination of dissolved and total recoverable antimony in water samples. This standard utilizes atomic absorption spectroscopy with vapor hydride generation, offering a sensitive and reliable approach to trace antimony analysis. Antimony detection in water is crucial due to its association with other industrial contaminants like lead and arsenic and its known toxicity. By following this standard, laboratories and water quality managers can ensure accurate monitoring of antimony concentrations in various water matrices, supporting regulatory compliance and safeguarding public health.

Key Topics

• Scope and Applicability:

  • The method covers quantification of antimony within the 1 to 15 μg/L range, addressing both dissolved and total recoverable forms.
  • It is applicable to water types such as reagent water, tap water, salt water, and untreated wastewaters.

• Significance and Use:

  • Provides a consistent approach for assessing toxicity risks associated with antimony exposure.
  • Addresses challenges of distinguishing antimony from lead and arsenic in industrial environments.
  • Suitable for routine environmental monitoring and regulatory reporting.

• Testing Procedure:

  • Water samples are preserved, digested with acids, and reacted chemically to convert antimony species into stibine gas for detection.
  • Determination is performed by atomic absorption spectroscopy at 217.6 nm, ensuring high sensitivity and specificity.

• Quality Control and Calibration:

  • Requires rigorous quality control measures, including calibration with blanks and standards, use of laboratory control samples, and regular verification of instrument performance.
  • Adherence to control limits and precision/bias evaluation is mandated for data reliability.

• Safety and Regulatory Considerations:

  • Emphasizes the user's responsibility for adhering to safety protocols and regulatory limits when handling reagents and samples.

Applications

• Drinking Water Analysis:

  • Ensures that drinking water supplies meet regulatory standards regarding antimony content, protecting consumer safety.

• Wastewater and Industrial Effluent Monitoring:

  • Facilitates the assessment of antimony in effluents from industries such as mining, metal processing, and chemical manufacturing.
  • Supports compliance with environmental discharge permits and local pollution control standards.

• Environmental Quality Assessments:

  • Helps in tracking the impact of anthropogenic activities on freshwater and marine ecosystems by monitoring antimony levels.

• Research and Method Validation:

  • Ideal for laboratory studies involving water chemistry, toxicity assessments, and method validation studies.

Related Standards

For a comprehensive and high-quality water analysis program, consider referencing these related ASTM standards:

• ASTM D5673 - Test Method for Elements in Water by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), an alternative technique suitable for multi-element analysis.
• ASTM D1193 - Specification for Reagent Water, ensures the purity of water used in analytical testing.
• ASTM D4691 - Practice for Measuring Elements in Water by Flame Atomic Absorption Spectrophotometry, offers guidance for elemental analysis by AAS.
• ASTM D4841 - Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents, crucial for sample preservation and integrity.
• ASTM D5810 - Guide for Spiking into Aqueous Samples, provides quality control procedures for verifying test method accuracy.
• ASTM D2777 - Practice for Determination of Precision and Bias of Applicable Test Methods, essential for method validation and performance assessment.

By following ASTM D3697-17 and associated standards, laboratories can achieve accurate, reproducible antimony measurements, supporting effective water quality management and regulatory compliance.

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: D3697 − 17
Standard Test Method for
Antimony in Water
This standard is issued under the fixed designation D3697; 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* D2777 Practice for Determination of Precision and Bias of
Applicable Test Methods of Committee D19 on Water
1.1 This test method covers the determination of dissolved
D3370 Practices for Sampling Water from Closed Conduits
and total recoverable antimony in water by atomic absorption
2 D4691 Practice for Measuring Elements in Water by Flame
spectroscopy.
Atomic Absorption Spectrophotometry
1.2 This test method is applicable in the range from 1 to 15
D4841 Practice for Estimation of Holding Time for Water
µg/L of antimony. The range may be extended by less scale
Samples Containing Organic and Inorganic Constituents
expansion or by dilution of the sample.
D5673 Test Method for Elements in Water by Inductively
1.3 The precision and bias data were obtained on reagent Coupled Plasma—Mass Spectrometry
D5810 Guide for Spiking into Aqueous Samples
water, tap water, salt water, and two untreated wastewaters.
The information on precision and bias may not apply to other D5847 Practice for Writing Quality Control Specifications
for Standard Test Methods for Water Analysis
waters.
1.4 The values stated in SI units are to be regarded as
3. Terminology
standard. The values given in parentheses are mathematical
conversion to inch-pound units that are provided for informa-
3.1 Definitions:
tion only and are not considered standard.
3.1.1 For definitions of terms used in this standard, refer to
Terminology D1129.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.2 Definitions of Terms Specific to This Standard:
responsibility of the user of this standard to establish appro-
3.2.1 continuing calibration blank, n—a solution contain-
priate safety and health practices and determine the applica-
ing no analytes (of interest) which is used to verify blank
bility of regulatory limitations prior to use.
response and freedom from carryover.
1.6 This international standard was developed in accor-
3.2.2 continuing calibration verification, n—a solution (or
dance with internationally recognized principles on standard-
setofsolutions)ofknownconcentrationusedtoverifyfreedom
ization established in the Decision on Principles for the
from excessive instrumental drift; the concentration is to cover
Development of International Standards, Guides and Recom-
the range of calibration curve.
mendations issued by the World Trade Organization Technical
3.2.3 laboratory control sample, n—a solution with a certi-
Barriers to Trade (TBT) Committee.
fied concentration of the antimony.
2. Referenced Documents
3.2.4 total recoverable antimony, n—a descriptive term
2.1 ASTM Standards: relating to forms of antimony that are determinable by the
D1129 Terminology Relating to Water digestion method which is included in the procedure; some
D1193 Specification for Reagent Water organic compounds may not be completely recovered.
4. Summary of Test Method
This test method is under the jurisdiction of ASTM Committee D19 on Water
4.1 Organic antimony-containing compounds are decom-
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
in Water.
posed by adding sulfuric and nitric acids and repeatedly
Current edition approved June 1, 2017. Published June 2017. Originally
evaporating the sample to fumes of sulfur trioxide. The
approved in 1978. Last previous edition approved in 2012 as D3697 – 12. DOI:
antimony so produced, together with inorganic antimony
10.1520/D3697-17.
originally present, is subsequently reacted with potassium
Platte, J.A., and Marcy,V. M., “ANewTool for theWater Chemist,” Industrial
Water Engineering, IWEGA, May 1965.
iodide and stannous chloride, and finally with sodium borohy-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dride to form stibine. The stibine is removed from solution by
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
aeration and swept by a flow of nitrogen into a hydrogen flame
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. where it is determined by atomic absorption at 217.6 nm.
*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
D3697 − 17
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.
8.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean reagent water conforming
to Specification D1193, Type I, II, or III water. Type I is
preferred and more commonly used. Other reagent water types
FIG. 1 Stibine Vapor Analyzer
may be used provided it is first ascertained that the water is of
sufficiently high purity to permit its use without adversely
affecting the precision and bias of the test method. Type II
water was specified at the time of round robin testing of these
5. Significance and Use
test methods.
5.1 Because of the association with lead and arsenic in
NOTE 3—The user must ensure the type of reagent water chosen is
industry, it is often difficult to assess the toxicity of antimony
sufficiently free of interferences. The water should be analyzed using the
and its compounds. In humans, complaints referable to the
test method.
nervous system have been reported. In assessing human cases,
8.3 Antimony Solution, Stock (1.00 mL = 100 µg Sb)—
however, the possibility of lead or arsenic poisoning must
Dissolve 274.3 mg of antimony potassium tartrate,
always be borne in mind. Locally, antimony compounds are
KSbOC H O ·1/2H O, in water and dilute to 1000 mL with
4 4 6 2
irritating to the skin and mucous membranes.
water. A purchased antimony stock solution of appropriate
5.2 ICP-MS may also be appropriate but at a higher instru-
known purity is also acceptable.
ment cost. See Test Method D5673.
8.4 Antimony Solution, Intermediate (1.00 mL = 10 µg
Sb)—Dilute 50.0 mL of antimony stock solution to 500.0 mL
6. Interference
with water.
6.1 Since the stibine is freed from the original sample
8.5 Antimony Solution, Standard (1.0 mL = 0.10 µg Sb)—
matrix, interferences in the flame are minimized.
Dilute 5.0 mL of antimony intermediate solution to 500.0 mL
6.2 Selenium and arsenic, which also form hydrides, do not
with water. Prepare fresh before each use, or as determined by
interfere at concentrations of 100 µg/L. Higher concentrations
Practice D4841. This standard is used to prepare working
were not tested.
standards at the time of analysis, or as determined by Practice
D4841.
7. Apparatus
8.6 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
7.1 Atomic Absorption Spectrophotometer, for use at 217.6
chloric acid (HCl).
nm with a scale expansion of approximately 3.Ageneral guide
8.7 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
for the use of flame atomic absorption applications is given in
Practice D4691. (HNO ).
8.8 Nitric Acid(1+1)—Add 250 mL of concentrated nitric
NOTE 1—The manufacturer’s instructions should be followed for all
instrumental parameters.
acid (sp gr 1.42) to 250 mL of water.
7.1.1 Antimony Electrodeless Discharge Lamp.
8.9 Potassium Iodide Solution (15 g/100 mL)—Dissolve 15
g of potassium iodide (KI) in 100 mLof water.This solution is
7.2 Recorder or Digital Readout—Any multirange variable
stable when stored in an amber bottle or in the dark.
speed recorder or digital readout accessory, or both, that is
compatible with the atomic absorption spectrophotometer is
8.10 Sodium Borohydride Solution (4 g/100 mL)—Dissolve
suitable.
4 g of sodium borohydride (NaBH)and2gof sodium
7.3 Stibine Vapor Analyzer, assembled as shown in Fig. 1. hydroxide (NaOH) in 100 mL water. Prepare weekly.
NOTE 2—A static system, such as one using a balloon, has been found 8.11 Stannous Chloride Solution (4.6 g/100 mL of concen-
to be satisfactory. See McFarren (1979).
trated HCl)—Dissolve5gof stannous chloride (SnCl ·H O) in
2 2
100 mL of concentrated HCl (sp gr 1.19). This solution is
8. Reagents and Materials
stable if a few small pieces of mossy tin are added to prevent
oxidation.
8.1 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 for the Com-
mittee on Analytical Reagents of the American Chemical 5
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
McFarren, E. F., “New, Simplified Method for Metal Analysis,” Journal of and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
American Water Works Association, JAWWA, Vol 64, 1972, p. 28. MD.
D3697 − 17
NOTE 5—If only dissolved antimony is to be determined, use a filtered
8.12 Sulfuric Acid (1 + 1)—Cautiously, and with constant
and acidified sample (9.2).
stirring and cooling, add 250 mL of concentrated sulfuric acid
(H SO , sp gr 1.84) to 250 mL of water.
11.3 To each container, add 7 mL of H SO (1+1)(8.12)
2 4 2 4
and5mLofconcentratedHNO (8.7).Addasmallboilingchip
8.13 Hydrogen, commercially available. Set pressure on
and carefully heat the samples (between 65°C to 95°C) on a
burner control box to 55 KPa (8 psi) and adjust flowmeter to
steam bath or hot plate below boiling in a well-ventilated hood
approximately 6 L/min.
to evaporate to fumes of SO . Maintain an excess of HNO
3 3
8.14 Nitrogen, commercially available. Set pressure on
untilallorganicmatterisdestroyed.Thispreventsdarkeningof
burner control box to 206.8 KPa (30 psi) and adjust flowmeter
the solution and possible reduction and loss of antimony. Cool,
for maximum sensitivity by volatilizing standards. A flow of
add 25 mL of water, and again evaporate to fumes of SO to
approximately 9 L/min has been found satisfactory. This will
expel oxides to nitrogen.
vary depending on the burner used.
NOTE 6—Many laboratories have found block digestion systems a
8.15 Filter Paper—Purchase suitable filter paper. Typically
useful way to digest samples for trace metals analysis. Systems typically
the filter papers have a pore size of 0.45-µm membrane.
consist of either a metal or graphite block with wells to hold digestion
Material such as fine-textured, acid-washed, ashless paper, or
tubes. The block temperature controller must be able to maintain unifor-
mity of temperature across all positions of the block. The digestion block
glass fiber paper are acceptable. The user must first ascertain
must be capable of maintaining a consistent temperature between 65°C
that the filter paper is of sufficient purity to use without
and 95°C. For trace metals analysis, the digestion tubes should be
adversely affecting the bias and precision of the test method.
constructed of polypropylene and have a volume accuracy of at least 0.5
%. All lots of tubes should come with a certificate of analysis to
9. Sampling
demonstrate suitability for their intended purpose.
9.1 Collect the sample in accordance with Practices D3370.
11.4 Cool, and adjust the volume of each container to
The holding time for the samples may be calculated in
approximately 100 mL with water.
accordance with Practice D4841.
11.5 To each container, add successively, with thorough
9.2 Immediately preserve samples with HNO (sp gr 1.42)
mixing after each addition, 8 mL of concentrated HCl (8.6), 1
to a pH of 2 or less at the time of collection; normally about 2
mL of KI solution (8.9), and 0.5 mL of SnCl (8.11) solution.
mL/L is required. If only dissolved antimony is to be
Allow about 15 min for reaction.
determined, filter the sample through a (No. 325) 0.45-µm
membrane filter before acidification. 11.6 Attach one container at a time to the rubber stopper
containing the gas dispersion tube.
NOTE 4—Alternatively, the pH may be adjusted in the laboratory within
14 days of
...

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: D3697 − 12 D3697 − 17
Standard Test Method for
Antimony in Water
This standard is issued under the fixed designation D3697; 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 determination of dissolved and total recoverable antimony in water by atomic absorption
spectroscopy.
1.2 This test method is applicable in the range from 1 to 15 μg/L of antimony. The range may be extended by less scale
expansion or by dilution of the sample.
1.3 The precision and bias data were obtained on reagent water, tap water, salt water, and two untreated wastewaters. The
information on precision and bias may not apply to other waters.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values statedgiven
in each system are mathematical conversions and may not be exact equivalents; therefore, each system shall be used independently
of the other.parentheses are mathematical conversion to inch-pound units that are provided for information only and are not
considered 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.
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:
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
D4691 Practice for Measuring Elements in Water by Flame Atomic Absorption Spectrophotometry
D4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents
D5673 Test Method for Elements in Water by Inductively Coupled Plasma—Mass Spectrometry
D5810 Guide for Spiking into Aqueous Samples
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
3. Terminology
3.1 Definitions:For definitions of terms used in this test method, refer to Terminology D1129.
3.1 Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 continuing calibration blank, n—a solution containing no analytes (of interest) which is used to verify blank response and
freedom from carryover.
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 Sept. 1, 2012June 1, 2017. Published September 2012June 2017. Originally approved in 1978. Last previous edition approved in 20072012 as
D3697 – 07.D3697 – 12. DOI: 10.1520/D3697-12.10.1520/D3697-17.
Platte, J. A., and Marcy, V. M., “A New Tool for the Water Chemist,” Industrial Water Engineering, IWEGA, May 1965.
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
D3697 − 17
FIG. 1 Stibine Vapor Analyzer
3.2.2 continuing calibration verification, n—a solution (or set of solutions) of known concentration used to verify freedom from
excessive instrumental drift; the concentration is to cover the range of calibration curve.
3.2.3 laboratory control sample, n—a solution with a certified concentration of the antimony.
3.2.4 total recoverable antimony, n—an arbitrary analytical a descriptive term relating to forms of antimony that are
determinable by the digestion method which is included in the procedure; some organic compounds may not be completely
recovered.
3.2.2 laboratory control sample, n—a solution with a certified concentration of the antimony.
4. Summary of Test Method
4.1 Organic antimony-containing compounds are decomposed by adding sulfuric and nitric acids and repeatedly evaporating the
sample to fumes of sulfur trioxide. The antimony so produced, together with inorganic antimony originally present, is subsequently
reacted with potassium iodide and stannous chloride, and finally with sodium borohydride to form stibine. The stibine is removed
from solution by aeration and swept by a flow of nitrogen into a hydrogen flame where it is determined by atomic absorption at
217.6 nm.
5. Significance and Use
5.1 Because of the association with lead and arsenic in industry, it is often difficult to assess the toxicity of antimony and its
compounds. In humans, complaints referable to the nervous system have been reported. In assessing human cases, however, the
possibility of lead or arsenic poisoning must always be borne in mind. Locally, antimony compounds are irritating to the skin and
mucous membranes.
5.2 ICP-MS may also be appropriate but at a higher instrument cost. See Test Method D5673.
6. Interference
6.1 Since the stibine is freed from the original sample matrix, interferences in the flame are minimized.
6.2 Selenium and arsenic, which also form hydrides, do not interfere at concentrations of 100 μg/L. Higher concentrations were
not tested.
7. Apparatus
7.1 Atomic Absorption Spectrophotometer, for use at 217.6 nm with a scale expansion of approximately 3. A general guide for
the use of flame atomic absorption applications is given in Practice D4691.
NOTE 1—The manufacturer’s instructions should be followed for all instrumental parameters.
7.1.1 Antimony Electrodeless Discharge Lamp.
7.2 Recorder or Digital Readout—Any multirange variable speed recorder or digital readout accessory, or both, that is
compatible with the atomic absorption spectrophotometer is suitable.
7.3 Stibine Vapor Analyzer, assembled as shown in Fig. 1.
NOTE 2—A static system, such as one using a balloon, has been found to be satisfactory. See McFarren, E. McFarren (1979).F., “New, Simplified
Method for Metal Analysis,” Journal of American Water Works Assoc., JAWWA, Vol 64, 1972, p. 28.
8. Reagents and Materials
8.1 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 for the Committee on Analytical Reagents of the American Chemical Society, where
McFarren, E. F., “New, Simplified Method for Metal Analysis,” Journal of American Water Works Association, JAWWA, Vol 64, 1972, p. 28.
D3697 − 17
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.
8.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Specification D1193, Type I, II, or III water. Type I is preferred and more commonly used. Other reagent water types may be used
provided it is first ascertained that the water is of sufficiently high purity to permit its use without adversely affecting the precision
and bias of the test method. Type II water was specified at the time of round robin testing of these test methods.
NOTE 3—The user must ensure the type of reagent water chosen is sufficiently free of interferences. The water should be analyzed using the test method.
8.3 Antimony Solution, Stock (1.00 mL = 100 μg Sb)—Dissolve 274.3 mg of antimony potassium tartrate, KSbOC H O ·1/
4 4 6
2H O, in water and dilute to 1000 mL with water. A purchased antimony stock solution of appropriate known purity is also
acceptable.
8.4 Antimony Solution, Intermediate (1.00 mL = 10 μg Sb)—Dilute 50.0 mL of antimony stock solution to 500.0 mL with water.
8.5 Antimony Solution, Standard (1.0 mL = 0.10 μg Sb)—Dilute 5.0 mL of antimony intermediate solution to 500.0 mL with
water. Prepare fresh before each use. use, or as determined by Practice D4841. This standard is used to prepare working standards
at the time of analysis.analysis, or as determined by Practice D4841.
8.6 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
8.7 Nitric Acid (sp gr 1.42)—Concentrated nitric acid (HNO ).
8.8 Nitric Acid (1 + 1)—Add 250 mL of concentrated nitric acid (sp gr 1.42) to 250 mL of water.
8.9 Potassium Iodide Solution (15 g/100 mL)—Dissolve 15 g of potassium iodide (KI) in 100 mL of water. This solution is
stable when stored in an amber bottle or in the dark.
8.10 Sodium Borohydride Solution (4 g/100 mL)—Dissolve 4 g of sodium borohydride (NaBH ) and 2 g of sodium hydroxide
(NaOH) in 100 mL water. Prepare weekly.
8.11 Stannous Chloride Solution (4.6 g/100 mL of concentrated HCl)—Dissolve 5 g of stannous chloride (SnCl ·H O) in 100
2 2
mL of concentrated HCl (sp gr 1.19). This solution is stable if a few small pieces of mossy tin are added to prevent oxidation.
8.12 Sulfuric Acid (1 + 1) (1 + 1)—Cautiously, and with constant stirring and cooling, add 250 mL of concentrated sulfuric acid
(H SO , sp gr 1.84) to 250 mL of water.
2 4
8.13 Hydrogen, commercially available. Set pressure on burner control box to 55 KPa (8 psi) and adjust flowmeter to
approximately 6 L/min.
8.14 Nitrogen, commercially available. Set pressure on burner control box to 206.8 KPa (30 psi) and adjust flowmeter for
maximum sensitivity by volatilizing standards. A flow of approximately 9 L/min has been found satisfactory. This will vary
depending on the burner used.
8.15 Filter Paper—Purchase suitable filter paper. Typically the filter papers have a pore size of 0.45-μm membrane. Material
such as fine-textured, acid-washed, ashless paper, or glass fiber paper are acceptable. The user must first ascertain that the filter
paper is of sufficient purity to use without adversely affecting the bias and precision of the test method.
9. Sampling
9.1 Collect the sample in accordance with Practices D3370. The holding time for the samples may be calculated in accordance
with Practice D4841.
9.2 Immediately preserve samples with HNO (sp gr 1.42) to a pH of 2 or less at the time of collection; normally about 2 mL/L
is required. If only dissolved antimony is to be determined, filter the sample through a (No. 325) 0.45-μm membrane filter before
acidification.
NOTE 4—Alternatively, the pH may be adjusted in the laboratory if the sample is returned within 14 days. within 14 days of collection. However, acid
must be added at least 24 hours before analysis to dissolve any metals that adsorb to the container walls. This could reduce hazards of working with acids
in the field when appropriate.
10. Standardization
10.1 Clean all glassware before use An effective way to clean all glassware to be used for preparation of standard solutions
or in the digestion step, or both, is by rinsing first with HNO (1 + 1) (8.8) and then with water.
10.2 Prepare, in 200 to 300-mL wide-mouth glass containers, a blank and sufficient standards that contain from 0.0 to 1.5 μg
of antimony by diluting 0.0 to 15.0-mL portions of the antimony standard solution to 100 mL with water.
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.
D3697 − 17
10.3 Proceed as directed in 11.3 to 11.8.
10.4 Prepare Read directly in concentration if this capability is provided with the instrument or prepare an analytical curve by
plotting recorder scale readings versus micrograms of antimony on linear graph paper or calculate a standard curve. Alternatively,
read directly in concentration if a concentration readout is provided with the instrument.
11. Procedure
11.1 Clean all glassware before use An effective way to clean all glassware to be used for preparation of standard solutions or
in the digestion step, or both, is by rinsing first with HNO (1 + 1) (8.8)(8.8) and then with water.reagent.
11.2 Pipet a volume of well-mixed acidified sample containing less than 1.5 μg of antimony (100-mL max) into a 200 to 300-mL
wide-mouth glass container, and dilute to 100 mL with water (see Fig. 1).
NOTE 5—If only dissolved antimony is to be determined, use a filtered and acidified sample (9.2).
11.3 To each container, add 7 mL of H SO (1 + 1) (8.12)(8.12) and 5 mL of concentrated HNO (8.7).(8.7). Add a small
2 4 3
boiling chip and carefully heat the samples (between 65°C to 95°C) on a steam bath or hot plate below boiling in a well-ventilated
hood to evaporate to fumes of SO . Maintain an excess of HNO until all organic matter is destroyed. This prevents darkening of
3 3
the solution and possible reduction and loss of antimony. Cool, add 25 mL of water, and again evaporate to fumes of SO to expel
oxides to nitrogen.
NOTE 6—Many laboratories have found block
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