ASTM D3868-04

Standard Test Method for Fluoride Ions in Brackish Water, Seawater, and Brines

SIGNIFICANCE AND USE
Identification of a brackish water, seawater, or brine is determined by comparison of the concentrations of their dissolved constituents. The results are used to evaluate the origin of the water, determine if it is a possible pollutant, or if it is related to a potential source of a valuable mineral. For example, in geochemical studies some correlation data indicate that fluoride is an indirect indicator of the presence of lithium.
SCOPE
1.1 This test method  covers the determination of soluble fluoride ions in brackish water, seawater and brines by use of a fluoride selective electrode.  
1.2 Samples containing from 1.0 to 25 mg/L can be analyzed by this test method.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 29-Feb-2004
• 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 D3868-95(1999) - Standard Test Method for Fluoride Ions in Brackish Water, Seawater, and Brines
• Effective Date: 01-Mar-2004
• Replaced By: ASTM D3868-09 - Standard Test Method for Fluoride Ions in Brackish Water, Seawater, and Brines
• Effective Date: 15-May-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 3868 – 04
Standard Test Method for
1
Fluoride Ions in Brackish Water, Seawater, and Brines
This standard is issued under the fixed designation D 3868; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope* 4. Summary of Test Method
2
1.1 This test method covers the determination of soluble 4.1 A fluoride selective electrode, reference electrode, and
fluoride ions in brackish water, seawater and brines by use of millivoltmeter are used to determine fluoride in brine samples
a fluoride selective electrode. by a standard addition method.
1.2 Samples containing from 1.0 to 25 mg/L can be ana- 4.2 The fluoride selective electrode consists of a lanthanum
lyzed by this test method. fluoride crystal that develops an electrode potential corre-
1.3 This standard does not purport to address all of the sponding to the level of fluoride ion in solution.
safety concerns, if any, associated with its use. It is the
5. Significance and Use
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 5.1 Identification of a brackish water, seawater, or brine is
determined by comparison of the concentrations of their
bility of regulatory limitations prior to use.
dissolved constituents. The results are used to evaluate the
2. Referenced Documents
origin of the water, determine if it is a possible pollutant, or if
3
2.1 ASTM Standards: it is related to a potential source of a valuable mineral. For
D1129 Terminology Relating to Water example,ingeochemicalstudiessomecorrelationdataindicate
D1193 Specification for Reagent Water that fluoride is an indirect indicator of the presence of lithium.
D2777 Practice for Determination of Precision and Bias of
6. Interferences
Applicable Methods of Committee D19 on Water
D3370 PracticesforSamplingWaterfromClosedConduits 6.1 Metal ions such as aluminum and iron (III) interfere
with the fluoride determination by forming complexes with
D5847 Practice for Writing Quality Control Specifications
for Standard Test Methods for Water Analysis fluoride ions. The buffer solution contains a complexing agent
that preferentially complexes these metal ions. This solution
3. Terminology
also contains a pH buffer to reduce electrode interference from
3.1 Definitions—For definitions of terms used in this test hydroxide ions and to prevent the formation of HF. Sodium
method, refer to Terminology D1129. chlorideisaddedasionicstrengthadjustor.Increasingamounts
of aluminum, iron (III), and borate ions were added to 1.5
mg/Lfluoridesolutionsandwerefoundnottointerfereupto5,
1
This test method is under the jurisdiction ofASTM Committee D19 on Water
350, and 250 mg/L (as boron), respectively.
andisthedirectresponsibilityofSubcommiteeD19.05onInorganicConstituentsin
Water.
7. Apparatus
Current edition approved March 1, 2004. Published April 2004. Originally
approved in 1979. Last previous edition approved in 1999 as D3868–95 (1999).
7.1 Millivoltmeter (accurate to 6 0.1 mV), specific ion
2
Additional information is contained in the following references: Hoke, S. H.,
meter.
Fletcher, G. E., and Collins, A. G., “Fluoride and Iodide Selective Electrodes
Applied to Oilfield Brine Analysis,” U.S. Department of Energy, Report of
NOTE 1—Aspecific ion meter that directly reads concentration may be
Investigations, BETC/RI-78/7.
used.
Rix, C. J., Bond,A. M., and Smith, J. D., “District Determination of Fluoride in
Sea Water with a Fluoride Selective Ion Electrode by a Method of Standard
7.2 Fluoride Selective Electrode, reference electrode.
Additions,” Analytical Chemistry, Vol 48, 1976, p. 1236.
7.3 Microlitre Pipets.
3
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.
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D 3868 – 04
8. Reagents
E = electrode potential of Solution A mV, and
A
E = electrode potential of Solution B,mV.
8.1 Purity of Reagents—Reagent grade chemicals shall be B
used in all tests. Unless otherwise indicated, it is intended that
NOTE 2—The slope of the electrode should meet the manufacturer’s
allreagentsshallconformtothespecificationoftheCommittee
specifications.
on Analytical Reagents of the American Chemical Society,
4 11.2 Calculatetheconcentrationoffluo
...