ASTM D3561-02(2007)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D3561 – 02 (Reapproved 2007)
Standard Test Method for
Lithium, Potassium, and Sodium Ions in Brackish Water,
Seawater, and Brines by Atomic Absorption
Spectrophotometry
This standard is issued under the fixed designation D3561; 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.
´ NOTE—Editorially updated Sections 10 and 12.4 in September 2007.
1. Scope 3. Terminology
1.1 This test method covers the determination of soluble 3.1 For definitions of terms used in this test method, refer to
lithium, potassium, and sodium ions in brackish water, seawa- Terminology D1129.
ter, and brines by atomic absorption spectrophotometry.
4. Summary of Test Method
1.2 Samplescontainingfrom0.1to70 000mg/Loflithium,
potassium, and sodium may be analyzed by this test method. 4.1 This test method is dependent on the fact that metallic
elements, in the ground state, will absorb light of the same
1.3 This test method has been used successfully with
artificial brine samples. It is the user’s responsibility to ensure wavelength they emit when excited. When radiation from a
given excited element is passed through a flame containing
the validity of this test method for waters of untested matrices.
1.4 This standard does not purport to address all of the ground state atoms of that element, the intensity of the
transmitted radiation will decrease in proportion to the amount
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- of ground state element in the flame. A hollow cathode lamp
whose cathode is made of the element to be determined
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. provides the radiation. The metal atoms to be measured are
placed in the beam of radiation by aspirating the specimen into
2. Referenced Documents
an oxidant fuel flame. A monochromator isolates the charac-
2.1 ASTM Standards: teristic radiation from the hollow cathode lamp, and a photo-
D1129 Terminology Relating to Water sensitive device measures the attenuated transmitted radiation,
D1193 Specification for Reagent Water which may be read as absorbance units or directly as concen-
D2777 Practice for Determination of Precision and Bias of tration on some instruments.
Applicable Test Methods of Committee D19 on Water 4.2 Sincethevariableandsometimeshighconcentrationsof
D3370 Practices for Sampling Water from Closed Conduits matrix materials in the waters and brines affect absorption
D5810 Guide for Spiking into Aqueous Samples differently,itisdifficulttopreparestandardssufficientlysimilar
D5847 Practice for Writing Quality Control Specifications to the waters and brines. To overcome this difficulty, the
for Standard Test Methods for Water Analysis method of additions is used in which three identical samples
are prepared and varying amounts of a standard added to two
of them. The three samples are then aspirated, the concentra-
This test method is under the jurisdiction of ASTM Committee D19 on Water
tion readings recorded, and the original sample concentration
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
calculated.
in Water.
Current edition approved Aug. 1, 2007. Published September 2007. Originally
approved in 1977. Last previous edition approved in 2002 as D3561 – 02. DOI: 5. Significance and Use
10.1520/D3561-02R07E01.
2 5.1 Identification of a brackish water, seawater, or brine is
Fletcher, G. F. and Collins, A. G., Atomic Absorption Methods of Analysis of
determined by comparison of the concentrations of their
Oilfield Brines: Barium, Calcium, Copper, Iron, Lead, Lithium, Magnesium,
Manganese, Potassium, Sodium, Strontium, and Zinc, U.S. Bureau of Mines, Report
of Investigations 7861, 1974, 14 pp. Collins,A. G. Geochemistry of OilfieldWaters,
Elsevier, New York, NY 1975.
3 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Angino, E. E., and Billings, G. K., Atomic Absorption Spectrophotometry in
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Geology, Elsevier Publishing Co., New York, NY 1967. Dean, J. A., and Rains, T.
Standards volume information, refer to the standard’s Document Summary page on C., Editors, Flame Emission and Atomic Absorption Spectrometry, Vol 1, Theory,
the ASTM website. Marcel Dekker, New York, NY 1969.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D3561 – 02 (2007)
dissolved constituents. The results are used to evaluate the 8.5 Potassium Solution, Standard (1 mL = 1 mg K)—
water as a possible pollutant, or as a commercial source of a Dissolve 1.907 g of potassium chloride (KCl) in water and
valuable constituent such as lithium. dilute to 1 Lwith water. One millilitre of this solution contains
1 mg of potassium. A purchased stock solution of adequate
6. Interferences
purity is also acceptable.
6.1 Ionization interference is controlled by adding large 8.6 Sodium Solution, Stock (1 mL = 100 mg Na)—Dissolve
254.2 g of sodium chloride (NaCl) in water and dilute to 1 L
excesses of an easily ionized element. Sodium ion is added in
the potassium and lithium determinations, and potassium ion is with water. A purchased stock solution of adequate purity is
also acceptable.
added in the sodium determinations.
8.7 Sodium Solution, Standard (1 mL = 10 mg Na)—
7. Apparatus
Dissolve25.42gofsodiumchloride(NaCl)inwateranddilute
to 1 L with water. One millilitre of this solution contains 1 mg
7.1 Atomic Absorption Spectrophotometer—The instrument
of sodium. A purchased stock solution of adequate purity is
shall consist of an atomizer and burner, suitable pressure-
regulating devices capable of maintaining constant oxidant and also acceptable.
fuelpressureforthedurationofthetest,ahollowcathodelamp 8.8 Oxidant:
for each metal to be tested, an optical system capable of 8.8.1 Air that has been cleaned and dried through a suitable
isolating the desired line of radiation, an adjustable slit, a filter to remove oil, water, and other foreign substances, is the
photomultiplier tube or other photosensitive device as a light usual oxidant.
measuring and amplifying device, and a readout mechanism 8.9 Fuel:
for indicating the amount of absorbed radiation.
8.9.1 Acetylene—Standard, commercially available acety-
7.1.1 Multielement Hollow-Cathode Lamps. lene is the usual fuel. Acetone, always present in acetylene
7.2 Pressure-Reducing Valves—The supplies of fuel and
cylinders, can be prevented from entering and damaging the
oxidant shall be maintained at pressures somewhat higher than burner head by replacing a cylinder that has only 100 psig (690
the controlled operating pressure of the instrument by suitable
kPa) of acetylene remaining.
valves.
9. Sampling
8. Reagents and Materials
9.1 Collect the sample in accordance with the applicable
8.1 Purity of Reagents—Reagent grade chemicals shall be
ASTM standard (see Practices D3370).
used in all tests. Unless otherwise indicated, it is intended that
allreagentsshallconformtothespecificationoftheCommittee
10. Procedure
on Analytical Reagents of the American Chemical Society,
10.1 Potassium is determined at the 766.5-nm wavelength,
where such specifications are available. Other grades may be
lithiumatthe670.8-nmwavelength,andsodiumatthe330.2to
used, provided it is first ascertained that the reagent is of
330.3-nm wavelength with an air-acetylene flame. For much
sufficiently high purity to permit its use without lessening the
greater sensitivity, sodium is determined at the 589.0 to
accuracy of the determination.
589.6-nm wavelength.
8.2 Purity of Water—Unless otherwise indicated, reference
10.2 Preliminary Calibration—Using micropipets prepare
towatershallbeunderstoodtomeanreagentwaterconforming
lithium standards containing 1 to 5 mg/Lof lithium, potassium
to Specification D1193, Type I. Other reagent water types may
standards containing 1 to 5 mg/L of potassium, and sodium
be used provided it is first ascertained that the water is of
standards containing 100 to 500 mg/L of sodium using the
sufficiently high purity to permit its use without adversely
standard lithium (8.3), potassium (8.5), and sodium (8.7)
affecting the precision and bias of the test method. Type III
solutions to 50-mL volumetric flasks. Before making up to
water was specified at the time of round robin testing of this
volume, add 0.5 mL of the sodium stock (8.6) solution to the
test method.
potassium and lithium standards, and to a blank. Before
8.3 Lithium Solution, Standard (1 mL = 1 mg Li)—Dissolve
making up to volume, add 0.5 mLof the potassium stock (8.4)
5.324goflithiumcarbonate(Li CO )inaminimumvolumeof
2 3
solution to the sodium standards and to a blank.Aspirate these
HCl (1 + 1). Dilute to 1 L with water. One millilitre of this
standards and the appropriate blank (for background setting)
solution contains 1 mg of lithium. A purchased stock solution
andadjustthecurvaturecontrols,ifnecessary,toobtainalinear
of adequate purity is also acceptable.
relationship between absorbance and the actual concentration
8.4 Potassium Solution, Stock (1 mL = 100 mg K)—
of the standards.
Dissolve 190.7 g of potassium chloride (KCl) in water and
10.3 Transfer an aliquot of water or brine (previously
diluteto1Lwithwater.Apurchasedstocksolutionofadequate
filtered through a 0.45-µm filter) to a 50-mL volumetric flask.
purity is also acceptable.
The specific gravity of the water or brine can be used to
estimate the lithium, potassium, or sodium content of the
sample and, thereby, serve as a basis for selecting the aliquot
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
sizes that will contain about 0.05 mg of lithium, 0.05 mg of
listed by the American Chemical Society, see Annual Standards for Laboratory
potassium, or 5 mg of sodium. Fig. 1 shows the relationship
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
betweensodiumconcentrationandspecificgravityforsomeoil
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. field brines from the Smackover formation.The concentrations
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D3561 – 02 (2007)
FIG. 1 Relationship of the Concentration of Sodium in Some Oilfield Brines to Specific Gravity
of sodium and also of lithium and potassium will not neces- 0.1 mg to the third. For sodium, add no standard to the first
sarily correlate with the concentrations found in other forma- flask, 5 mg to the second, and 10 mg to the third.
tions. Therefore, the user of this test method may find it
10.5 Add 0.5 mL of the sodium stock (8.6) solution to the
necessary to draw similar curves for brine samples taken from
potassium and lithium samples and 0.5 mL of the potassium
other formations. Add 0.5 mL of the sodium stock (8.6)
stock (8.4) solution to the sodium samples, dilute to volume,
solution to the lithium and potassium samples and 0.5 mL of
aspirate, and record the absorbance readings for each sample.
thepotassiumstock(8.4)solutiontothesodiumsamples,dilute
to volume, and aspirate. Calculate the approximate sample
11. Calculation
concentration from the preliminary calibration readings, and
11.1 Calculate the concentration of potassium, lithium, or
determine the aliquot sizes that will contain about 0.05 mg of
sodium ion in the original sample in milligrams per litre as
lithium, 0.05 mg of potassium, or 5 mg of sodium.
follows:
10.4 Transfer equal aliquots containing about 0.05 mg of
11.2
potassium or lithium, or 5 mg of sodium to three 50-mL
volumetric flasks.Add no potassium or lithium standard to the V ~A 3 C !
1 s std
Concentration, mg/L 5 (1)
first flask, using a micropipet add 0.05 mg to the second, and V ~A 2 A !
2 std s
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D3561 – 02 (2007)
TABLE 1 Compositions of Artificial Brine Samples
where:
g/L
V = volume of the dilute sample, mL,
V = volume of the original sample, mL,
Sample No. 1 2 3 4
A = absorbance of dilute sample, A
s
Na 9.14 62.5 29.0 66.2
B
A = absorbance of one of the standard additions, and
K 0.591 1.670 1.650 1.921
std
2 C
Li 0.0210 0.0523 0.0741 0.164
C = concentration of the same standard addition as A
std std
CaCl 1.47 2.86 1.93 4.67
in mg/L.
MgCl ·6H O 9.40 10.19 4.12 1.99
2 2
Sincetherearetwostandardadditions,calculateforeachand
BaCl 0.05 0.95 0.48 0.47
average the two results. A
Added to the aqueous solution as NaCl.
B
Added to the aqueous solution as KCl, KBr, and Kl: Sample No. 1 contained
0.470 g/L of KCl, 0.979 g/L of KBr, and 0.098 g/L of Kl; Sample No. 2 contained
12. Precision and Bias
1.774 g/L of KCl, 1.909 g/L of KBr, and 0.477 g/L of Kl; Sample No. 3 contained
12.1 The precision of this test method within its designated
1.721g/LofKCl,1.928g/LofKBr,and0.482g/LofKl;andSampleNo.4contained
2.072 g/L of KCl, 1.870 g/L of KBr, and 0.934 g/L of Kl.
range may be expressed as follows:
C
Added to the aqueous solution as LiCl.
Lithium,
S 5 0.0677X 1 3.127
t
12.4 Precision and bias for this test method conforms to
S 5 0.0486X 1 1.936
o
Practice D2777 – 77, which was in place at the time of
Potassium,
collaborative testing. Under the allowances made in 1.4 of
D2777 – 06, these precision and bias data do meet existing
S 5 0.1443X 2 2.317
t
requirements for interlaboratory studies of Committee D19 test
S 5 0.0847X 2 61.15
o
methods.
Sodium,
13. Quality Control
S 5 0.08905X 1 729
t
13.1 In order to be certain that analytical values obtained
S 5 0.0295X 1 195
o
using these test methods are valid and accurate within the
confidencelimitsofthetest,thefollowingQCproceduresmust
where:
be followed when analyzing lithium, potassium, and sodium.
S = overall precision,
t
13.2 Calibration and Calibration Verification:
S = single-operator precision, and
o
13.2.1 Analyze at least three working standards containing
X = concentration of lithium, potassium, or sodium deter-
concentrations of lithium, potassium, and sodium that bracket
mined, mg/L.
the expected sample concentration prior to analysis of samples
12.2 The bias of this test method determined from recover-
to calibrate the instrument.
ies of known amounts of lithium, potassium, and sodium in a
13.2.2 Verify instrument calibration after standardization by
series of prepared standards were as follows:
analyzing a standard at the concentration of one of the
Lithium, Amount Added,
...