ASTM D1691-02(2007)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D1691 − 02(Reapproved 2007)
Standard Test Methods for
Zinc in Water
This standard is issued under the fixed designation D1691; 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 Department of Defense.
´ NOTE—Practice D2777 – 98 was editorially changed throughout to D2777 – 06 in August 2007.
1. Scope in Closed Conduits (Withdrawn 2003)
D1193 Specification for Reagent Water
1.1 These test methods cover the determination of zinc in
D1687 Test Methods for Chromium in Water
water. Two test methods are given as follows:
D1688 Test Methods for Copper in Water
Test Method Concentration Sections
D1886 Test Methods for Nickel in Water
Range
D2777 Practice for Determination of Precision and Bias of
A—Atomic Absorption, Direct 0.05 to 2 mg/L 8-16
B—Atomic Absorption, 20 to 200 µg/L 17-25
Applicable Test Methods of Committee D19 on Water
Chelation-Extraction
D3370 Practices for Sampling Water from Closed Conduits
1.2 Either dissolved or total recoverable zinc may be deter-
D3557 Test Methods for Cadmium in Water
mined.
D3558 Test Methods for Cobalt in Water
D3559 Test Methods for Lead in Water
1.3 These test methods have been used successfully with
D4841 Practice for Estimation of Holding Time for Water
reagent grade water. See the specific test method for applica-
Samples Containing Organic and Inorganic Constituents
bility to other matrices. It is the user’s responsibility to assure
D5810 Guide for Spiking into Aqueous Samples
the validity of these test methods in other matrices.
D5847 Practice for Writing Quality Control Specifications
1.4 This standard does not purport to address all of the
for Standard Test Methods for Water Analysis
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Definitions—For definitions of terms used in these test
bility of regulatory limitations prior to use. For specific hazard
methods, refer to Terminology D1129.
statements, see Section 6 and Note 5, Note 8, and Note 13.
1.5 Two former colorimetric test methods were discontin-
3.2 Definitions:
ued. Refer to Appendix X1 for historical information. 3.2.1 total recoverable zinc—an arbitrary analytical term
relating to the recoverable form of zinc that is determinable by
2. Referenced Documents the digestion method which is included in the Procedure.
2.1 ASTM Standards:
4. Significance and Use
D858 Test Methods for Manganese in Water
4.1 Zinc is an essential and beneficial element in body
D1066 Practice for Sampling Steam
growth. Concentrations above 5 mg/L can cause a bitter
D1068 Test Methods for Iron in Water
astringent taste and opalescence in alkaline waters. The zinc
D1129 Terminology Relating to Water
concentration of U.S. drinking waters varies between 0.06 and
D1192 Guide for Equipment for Sampling Water and Steam
7.0 mg/L with a mean of 1.33 mg/L. Zinc most commonly
enters the domestic water supply from deterioration of galva-
nized iron and dezincification of brass. Zinc in water also may
These test methods are under the jurisdiction of ASTM Committee D19 on 4
result from industrial water pollution.
Water and are the direct responsibility of Subcommittee D19.05 on Inorganic
Constituents in Water.
5. Purity of Reagents
Current edition approved Aug. 1, 2007. Published August 2007. Originally
approved in 1959. Last previous edition approved in 2002 as D1691 – 02. DOI:
10.1520/D1691-02R07E01.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on “Standard Methods for the Examination of Water and Wastewater,” 16th
the ASTM website. edition, 1985, APHA, AWWA-WPCF.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D1691 − 02 (2007)
5.1 Reagent grade chemicals shall be used in all tests. ment. Total recoverable zinc is determined by aspirating the
Unless otherwise indicated, it is intended that all reagents shall sample following hydrochloric-nitric acid digestion and filtra-
conform to the specifications of the Committee on Analytical tion. The same digestion procedure is used to determine total
Reagents of the American Chemical Society, where such recoverable cadmium (Test Methods D3557), chromium, (Test
specifications are available. Other grades may be used, pro- Methods D1687), cobalt (Test Methods D3558), copper (Test
vided it is first ascertained that the reagent is of sufficiently Methods D1688), iron (Test Methods D1068), lead (Test
high purity to permit its use without lessening the accuracy of Methods D3559), manganese (Test Methods D858), and nickel
the determination. (Test Methods D1886).
5.2 Purity of Water—Unless otherwise indicated, references
10. Interferences
towatershallbeunderstoodtomeanreagentwaterconforming
to Specification D1193, Type I. Other reagent water types may
10.1 Sodium, potassium, sulfate, and chloride (9000 mg/L
be used, provided it is first ascertained that the water is of each),calciumandmagnesium(4000mg/Leach),nitrate(2000
sufficiently high purity to permit its use without adversely
mg/L), and cadmium, lead, copper, nickel, cobalt, and chro-
affecting the bias and precision of the test method. Type II mium (10 mg/L each) do not interfere.
water was specified at the time of round-robin testing of this
10.2 Background correction or a chelation-extraction proce-
test method.
dure (see Test Method B) may be necessary to determine low
levels of zinc in some waters.
6. Hazards
NOTE 1—Instrument manufacturers’ instructions for use of the specific
6.1 Although zinc is nontoxic to man, these test methods
correction technique should be followed.
require the use of certain other toxic and hazardous reagents
and materials. Each should be used with care and exerting
11. Apparatus
proper precautions.
11.1 Atomic Absorption Spectrophotometer , for use at
7. Sampling
213.9 nm.
7.1 Collect the sample in accordance with Practice D1066,
NOTE 2—The manufacturer’s instructions should be followed for all
Specification D1192, and Practices D3370, as applicable.
instrumental parameters.Wavelengths other than 213.9 nm may be used if
they have been determined to be equally suitable.
7.2 Samples shall be preserved with nitric acid (HNO ) (sp
11.1.1 Zinc Light Source—Hollow-cathode lamps or elec-
gr 1.42) to a pH of 2 or less immediately at the time of
trodeless discharge lamps have been found satisfactory.
collection, normally about 2 mL/L of HNO . If only dissolved
zinc is to be determined, the sample, shall be filtered through
11.2 Oxidant—See 12.6.
a 0.45-µm membrane filter before acidification. The holding
11.3 Fuel—See 12.7.
timeforsamplesmaybecalculatedinaccordancewithPractice
11.4 Pressure-Reducing Valves—The supplies of fuel and
D4841.
oxidant shall be maintained at pressures somewhat higher than
TEST METHOD A—ATOMIC ABSORPTION, DIRECT
the controlled operating pressure of the instrument by suitable
valves.
8. Scope
8.1 This test method covers the determination of dissolved
12. Reagents and Materials
and total recoverable zinc in most waters and wastewaters.
12.1 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
8.2 This test method is applicable in the range from 0.05 to
chloric acid (HCl).
2.0 mg/Lof zinc.The range may be extended to concentrations
NOTE 3—If the reagent blank concentration is greater than the method
greater than 2.0 mg/L by dilution of the sample.
detection limit, distill the HCl or use a spectrograde acid. Warning—
When HCl is distilled an azeotropic mixture is obtained (approximately 6
8.3 This test method has been used successfully with
N HCl). Therefore, whenever concentrated HCl is specified in the
reagent grade water, river water, wastewater, ground water, tap
preparation of a reagent or in the procedure, use double the amount
water, lake water, refinery effluent. The information on preci-
specified if a distilled acid is used.
sion and bias may not apply to other waters.
12.2 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
(HNO ).
9. Summary of Test Method
NOTE 4—If the reagent blank concentration is greater than the method
9.1 Zinc is determined by atomic absorption spectropho-
detection limit, distill the HNO or use a trace metal grade acid.
tometry. Dissolved zinc is determined by aspirating a portion 3
of the filtered and preserved sample directly with no pretreat- 12.3 Nitric Acid (1 +499)—Add 1 volume of HNO (sp gr
1.42) to 499 volumes of water.
12.4 Zinc Solution, Stock (1 mL = 1.0 mg Zn)—Dissolve
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
1.245gofzincoxide(ZnO)inamixtureof10mLofHNO (sp
listed by the American Chemical Society, see Annual Standards for Laboratory
gr 1.42) and 10 mL of water. Dilute to 1 L with water. A
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
purchased stock solution of appropriate purity is also accept-
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. able.
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D1691 − 02 (2007)
TABLE 1 Determination of Precision and Bias for Zinc by Atomic
12.5 Zinc Solution, Standard (1 mL = 0.1 mg Zn)—Dilute
Absorption, Direct
100.0 mL of the zinc stock solution and 1 mL of HNO (sp gr
Amount Amount Statistically
1.42) to 1 L with water.
S , S , %,
T O
Added, Found, Significant,
mg/L mg/L Bias
mg/L mg/L 95 % Level
12.6 Oxidant:
Reagent Water
12.6.1 Air,whichhasbeenpassedthroughasuitablefilterto
0.16 0.172 0.052 0.038 + 7.5 No
remove oil, water, and other foreign substances, is the usual
0.80 0.798 0.068 0.034 −0.2 No
1.50 1.459 0.107 0.041 −2.7 Yes
oxidant.
Water of Choice
12.7 Fuel: 0.16 0.172 0.041 0.033 + 7.5 Yes
0.80 0.796 0.081 0.047 −0.5 No
12.7.1 Acetylene—Standard, commercially available acety-
1.50 1.446 0.098 0.060 −3.6 Yes
lene is the usual fuel. Acetone, always present in acetylene
cylinders, can affect analytical results. The cylinder should be
replaced at 50 psig (345 kPa).
14.5 Aspirate each filtered and acidified sample and stan-
dard and determine its absorbance or concentration at 213.9
NOTE 5—Warning: “Purified” grade acetylene containing a special
nm. Atomize HNO (1 +499) between each sample and stan-
proprietary solvent rather than acetone should not be used with poly(vinyl 3
chloride) tubing as weakening of the tubing walls can cause a potentially dard.
hazardous situation.
15. Calculation
13. Standardization
15.1 Calculate the concentration of zinc in each sample, in
milligrams per litre, using the analytical curve prepared in 13.4
13.1 Prepare 100 mL each of a blank and at least four
or read directly in concentration.
standard solutions to bracket the expected zinc concentration
range of the samples to be analyzed by diluting the standard
16. Precision and Bias
zincsolution(12.5)withHNO (1 +499).Preparethestandards
16.1 The overall precision and bias of this test method,
each time the test is to be performed and select so as to give
within its designated range, is shown in Table 1.
zero, middle, and maximum points for an analytical curve.
16.2 These collaborative test data were obtained from
13.2 When determining total recoverable zinc, add 0.5 mL
eleven laboratories on reagent grade, river, lake, ground and
of HNO (sp gr 1.42) to each blank and standard solution and
effluent waters. For other waters these data may not apply.
proceed as directed in 14.2-14.4. After the digestion of the
blankandstandardsolutionshasbeencompletedin14.4,return 16.3 Precision and bias for this test method conform to
to 13.3 to complete the standardization for total recoverable Practice D2777 – 77, which was in place at the time of
determinations. To determine dissolved zinc, proceed with collaborative testing. Under the allowances made in 1.4 of
13.3. Practice D2777 – 06, these precision and bias data do meet
existing requirements for interlaboratory studies of Committee
13.3 Aspirate the blank and standards, and record the
D19 test methods.
absorbance of each at 213.9 nm. Aspirate HNO (1 +499)
between each standard.
TEST METHOD B—ATOMIC ABSORPTION,
CHELATION–EXTRACTION
13.4 Prepare an analytical curve by plotting the absorbance
versus concentration for each standard. Alternatively, read
17. Scope
directly in concentration from the instrument.
17.1 This test method covers the determination of dissolved
and total recoverable zinc in most waters and brines.
14. Procedure
17.2 This test method is applicable in the range from 20 to
14.1 Measure 100.0 mL of a well-mixed acidified sample
200 µg/L of zinc.
into a 125-mL beaker or flask.
17.3 This test method has been used successfully with
NOTE 6—If only dissolved zinc is to be determined, start with 14.5.
reagent grade water, river water, wastewater, ground water, tap
14.2 Add 5 mL of HCl (sp gr 1.19) to each sample. water, lake water, refinery effluent. The information on preci-
sion and bias may not apply to other waters.
14.3 Heat the samples on a steam bath or hotplate in a
well-ventilated hood until the volume has been reduced to 15
18. Summary of Test Method
to 20 mL, making certain that the samples do not boil.
18.1 Zinc is determined by atomic absorption spectropho-
tometry. The element, either dissolved or total recoverable, is
NOTE 7—For samples with appreciable amounts of suspended matter or
dissolved solids, the amount of reduction in the volume is left to the
chelated with pyrrolidine dithiocarbamic acid and extracted
discretion of the analyst.
with chloroform. The extract is evaporated to dryness, treated
with hot nitric acid to destroy organic matter, dissolved in
14.4 Cool and filter the samples through a suitable filter,
such as fine-textured, acid-washed, ashless paper, into 100-mL
volumetric flasks.Wash the filter paper two or three times with
SupportingdataareavailablefromASTMInternationalHeadquarters,100Barr
water and adjust to volume. Harbor Dr., West Conshohocken, PA 19428-2959. Request RR:D19-1039.
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D1691 − 02 (2007)
hydrochloricacid,anddilutedtoaspecifiedvolumewithwater. 22.2 When determining total recoverable zinc
...