ASTM D3866-92(1996)
(Test Method)Standard Test Methods for Silver in Water
Standard Test Methods for Silver in Water
SCOPE
1.1 These test methods cover the atomic absorption determination of silver in water. Three test methods are given as follows: ConcentrationRange SectionsTest Method A—Atomic Absorp-tion-Chelation-Extraction 1 to 10 μg/L7 to 15Test Method B—Atomic Absorp-tion-Direct0.1 to 10 mg/L16 to 24Test Method C—Atomic Absorp-tion-Graphite Furnace 1 to 25 μg/L25 to 33
ASimilar to that in Brown, E., Skougstad, M. W., and Fishman, M. J.," Methods for Collection and Analysis of Water Samples for Dissolved Minerals and Gases," Techniques of Water Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A1, 1970, p. 46.
1.2 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. Specific precautionary statements are given in Note 3, Note 5, Note 9, and Note 13.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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 3866 – 92 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Methods for
Silver in Water
This standard is issued under the fixed designation D 3866; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 total recoverable silver—an arbitrary analytical term
relating to forms of silver that are determinable by the
1.1 These test methods cover the atomic absorption deter-
digestion method that is included in the procedures.
mination of silver in water. Three test methods are given as
3.2 Definitions—For definition of terms used in these test
follows:
methods, refer to Terminology D 1129.
Concentration
Range Sections
4. Significance and Use
Test Method A—Atomic Absorp- 1 to 10 μg/L 7 to 15
A
4.1 The principal adverse effect of silver in the body is
tion—Chelation-Extraction
Test Method B—Atomic Absorp- 0.1 to 10 mg/L 16 to 24 cosmetic. It causes argyria, a permanent, blue-gray discolora-
tion—Direct
tion of the skin, eyes, and mucous membranes.
Test Method C—Atomic Absorp- 1 to 25 μg/L 25 to 33
4.2 Relatively small quantities of silver are bactericidal or
tion—Graphite Furnace
A
bacteriostatic and find limited use in both disinfection of
Similar to that in Brown, E., Skougstad, M. W., and Fishman, M. J.,“ Methods
for Collection and Analysis of Water Samples for Dissolved Minerals and Gases,”
swimming pool waters and point-of-use water filters.
Techniques of Water-Resources Investigations of the U.S. Geological Survey,
Book 5, Chapter A1, 1970, p. 46.
5. Purity of Reagents
1.2 This standard does not purport to address all of the
5.1 Reagent grade chemicals shall be used in all tests.
safety concerns, if any, associated with its use. It is the
Unless otherwise indicated, it is intended that all reagents shall
responsibility of the user of this standard to establish appro-
conform to the specifications of the Committee on Analytical
priate safety and health practices and determine the applica-
Reagents of the American Chemical Society, when such
bility of regulatory limitations prior to use. Specific precau-
specifications are available. Other grades may be used, pro-
tionary statements are given in Note 3, Note 5, Note 9, and
vided it is first ascertained that the reagent is of sufficiently
Note 13.
high purity to permit its use without lessening the accuracy of
2. Referenced Documents
the determination.
5.2 Purity of Water—Unless otherwise indicated, references
2.1 ASTM Standards:
to water shall be understood to mean reagent water conforming
D 1129 Terminology Relating to Water
to Specification D 1193, Type I, II, or III water. Type I is
D 1193 Specification for Reagent Water
preferred and more commonly used. Type II water was
D 2777 Practice for Determination of Precision and Bias of
specified at the time of round robin testing of these test
Applicable Test Methods of Committee D-19 on Water
methods.
D 3370 Practices for Sampling Water from Closed Con-
duits
NOTE 1—The user must ensure the type of reagent water chosen is
D 3919 Practice for Measuring Trace Elements in Water by
sufficiently free of interferences. The water should be analyzed using the
Graphite Furnace Atomic Absorption Spectrophotometry test method.
D 4691 Practice for Measuring Elements in Water by Flame
2 6. Sampling
Atomic Absorption Spectrophotometry
6.1 Collect the sample in accordance with Practices D 3370.
D 4841 Practice for Estimation of Holding Time for Water
The holding time for the samples may be calculated in
Samples Containing Organic and Inorganic Constituents
accordance with Practice D 4841.
3. Terminology
6.2 Preserve samples for Test Method A with HNO (sp gr
1.42) to a pH of 2 or less immediately at the time of collection;
3.1 Definition of Term Specific to These Test Methods:
1 3
These test methods are under the jurisdiction of ASTM Committee D-19 on Reagent Chemicals, American Chemical Society Specifications, American
Water and are the direct responsibility of Subcommittee D19.05 on Inorganic Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Constituents in Water. listed by the American Chemical Society, see Analar Standards for Laboratory
Current edition approved May 15, 1992. Published September 1992. Originally Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
published as D 3866 – 79. Last previous edition D 3866 – 82 (1987). and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 11.01. MD.
D 3866
normally about 2 mL/L is required. If only dissolved silver is lution (1 g/100 mL)—Dissolve 1.0 g of APDC in 100 mL of
to be determined, filter the sample at time of collection through water. Prepare fresh before each use.
a 0.45-μm membrane filter before acidification.
11.2 Bromophenol Blue Indicator Solution (0.1 g/100
6.3 Do not preserve samples for Test Methods B and C at mL)—Dissolve 0.1 g of bromophenol blue in 100 mL of 50 %
the time of collection. If only dissolved silver is to be ethanol or isopropanol.
determined, filter the sample through a 0.45-μm membrane 11.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
filter at time of collection. Add cyanogen iodide (CNI) solution
chloric acid (HCl).
to the samples in the laboratory prior to analysis. For total 11.4 Hydrochloric Acid (1 + 49)—Add 1 volume of hydro-
recoverable silver it is preferable to add the cyanogen iodide to
chloric acid (HCl, sp gr 1.19) to 49 volumes of water.
the entire sample to avoid a nonhomogeneous solution; there- 11.5 Methyl Isobutyl Ketone (MIBK).
fore, it is advisable to collect a discrete sample for silver.
NOTE 3—Warning: Avoid inhalation and conduct all manipulation in
a well-ventilated hood.
TEST METHOD A—ATOMIC ABSORPTION—
CHELATION EXTRACTION
11.6 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
(HNO ).
7. Scope 3
7.1 This test method covers the determination of dissolved NOTE 4—If a high reagent blank is obtained, distill the HNO or use a
spectrograde acid.
and total recoverable silver in most water and wastewaters.
7.2 This test method is applicable in the range from 1 to 10
11.7 Silver Solution, Stock (1.0 mL 5 100 μg Ag)—Crush
μg/L of silver. The range may be extended by dilution of the
approximately2gof silver nitrate (AgNO ) crystals and dry to
original sample.
constant mass at 40°C. Dissolve 0.1575 g of AgNO in water
7.3 This test method has been used successfully with
containing 5 mL of concentrated HNO and dilute to 1000 mL.
reagent water, natural surface water, and drinking water. The
Store in an amber glass bottle.
information on precision and bias may not apply to other
11.8 Silver Solution, Intermediate (1.0 mL 5 1.00 μg Ag)—
waters. It is the user’s responsibility to ensure the validity of
Dilute 10.0 mL of silver stock solution and 5 mL of concen-
this test method for waters of untested matrices.
trated HNO to 1000 mL with water. Store in an amber glass
bottle.
8. Summary of Test Method
11.9 Silver Solution, Standard (1.0 mL 5 0.100 μg Ag)—
8.1 Silver is determined by atomic absorption spectrometry.
Dilute 100 mL of silver intermediate solution and 5 mL of
The element, either dissolved or total recoverable, is chelated
concentrated HNO to 1000 mL with water. Prepare fresh
with ammonium pyrrolidine dithiocarbamate (APDC) and
before use.
extracted with methyl isobutyl ketone (MIBK). The extract is
11.10 Sodium Hydroxide Solution (100 g/L)—Dissolve 100
aspirated into an air-acetylene flame of the spectrophotometer.
g of NaOH in water and dilute to 1000 mL.
Total recoverable silver is determined following nitric acid
11.11 Oxidant:
digestion and filtration.
11.11.1 Air, that has been passed through a suitable filter to
9. Interferences
remove oil, water, and other foreign substances is the usual
oxidant.
9.1 Concentrations of iron greater than 25 mg/L interfere by
11.12 Fuel:
suppressing the silver absorption.
11.12.1 Acetylene-Standard, commercially available acety-
10. Apparatus
lene is the usual fuel. Acetone, always present in acetylene
10.1 Atomic Absorption Spectrophotometer for use at 328.1
cylinders, can affect analytical results. The cylinder should be
nm. A general guide for the use of flame atomic absorption
replaced at 50 psig (345 kPa). (Warning, see Note 5.)
applications is given in Practice D 4691.
NOTE 5—Warning: “Purified” grade acetylene containing a special
NOTE 2—The manufacturer’s instructions should be followed for in- proprietary solvent rather than acetone must not be used with poly(vinyl
strumental parameters. Wave-lengths other than 328.1 nm may be used if chloride) tubing as weakening of the tubing walls causes a potentially
they have been determined to be equally suitable. hazardous situation.
10.2 Silver Hollow-Cathode Lamp.
12. Standardization
10.3 Pressure-Reducing Valves—The supplies of fuel and
12.1 Prepare a blank and sufficient standards containing
oxidant shall be maintained at pressures somewhat higher than
from 0.0 to 1.0 μg of silver by diluting 0.0 to 10.0-mL portions
the controlled operating pressure of the instrument by suitable
of silver standard solution to approximately 100 mL.
pressure-reducing valves.
12.2 To determine total recoverable silver, use 125-mL
11. Reagents and Materials
beakers or flasks, add 5.0 mL of HNO (sp gr 1.42), and
11.1 Ammonium Pyrrolidine Dithiocarbamate (APDC) So-
proceed as directed in 13.3 through 13.10. To determine
dissolved silver use 200-mL volumetric flasks and proceed as
directed in 13.5 through 13.10. Treat the blank and each
Similar to that in Brown, E., Skougstad, M. W., and Fishman, M. J.,“ Methods
standard in the same manner as the samples.
for Collection and Analysis of Water Samples for Dissolved Minerals and Gases,”
12.3 Construct an analytical curve by plotting the absor-
Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book
5, Chapter A1, 1970, p. 46. bances of standards versus micrograms of silver. Alternatively,
D 3866
TABLE 1 Determination of Bias and Precision for Test Method A
13.10 Atomize the ketone layer and record the scale reading
Statistically or concentration (Note 11). Aspirate water-saturated MIBK
Amount Amount
Significant, Overall
between each sample.
Added, Found, Bias, Degrees of
95 % Precision,
μg/L μg/L % Freedom
Confidence S
t
NOTE 11—It is necessary to reduce the acetylene flow when aspirating
Ag Ag
Level
an organic solvent (MIBK) to obtain a nonluminous flame. Also allow the
Reagent Water, Type II
flame conditions to come to equilibrium before aspirating samples.
2.0 2.18 + 9.0 no 0.77 7
5.0 5.15 + 3.0 no 1.34 7
14. Calculation
8.0 8.08 + 1.0 no 1.86 7
Natural Water of Choice 14.1 Determine the weight of silver in each sample by
2.0 2.37 + 18.5 yes 0.74 7
referring to 12.3. Calculate the concentration of silver in
5.0 4.99 −0.2 no 0.92 7
micrograms per litre as follows:
8.0 8.38 + 4.8 no 2.21 7
Silver, μg/L 5 ~1000/A! 3 B
where:
read directly in concentration if this capability is provided with
A 5 volume of original sample, mL, and
the instrument.
B 5 weight of silver in sample, μg.
13. Procedure
15. Precision and Bias
13.1 Measure a volume of a well-mixed acidified sample
15.1 The single-operator and overall precision of this test
containing less than 1.0 μg of silver (100-mL maximum) into
method within its designated range for four laboratories, which
a 125-mL beaker or flask and adjust the volume to 100 mL with
include a total of seven operators analyzing each sample on
water.
three different days varies with the quantity being tested, see
Table 1.
NOTE 6—If only dissolved silver is to be determined, measure a volume
of filtered and acidified sample containing less than 1.0 μg of silver (100
15.2 Recoveries of known amounts of silver (from silver
mL maximum) into a 200-mL volumetric flask and adjust the volume to
nitrate) in a series of prepared standards for the same
100 mL and start with 13.5.
laboratories and operators are shown in Table 1.
13.2 Add 5 mL of HNO (sp gr 1.42) to each sample. 15.3 The collaborative test data were obtained on reagent
13.3 Heat the samples on a steam bath or hot plate in a water, natural surface water, and drinking water. This data may
well-ventilated hood until the volume has been reduced to 15 not apply to untested matrices. It is the user’s responsibility to
to 20 mL making certain that the samples do not boil. ensure the validity of this test method for waters of untested
matrices.
NOTE 7—For brines and samples with a high concentration of sus-
15.4 This precision and bias statement conforms to Practice
pended matter, the amount of reduction in volume is left to the discretion
D 2777 – 77, which was in place at the time of round robin
of the analyst.
testing. It does not meet the requirements of Practice
13.4 Cool and filter each sample through a filter (such as a
D 2777 – 86.
fine-textured acid washed, ashless paper) into a 200-mL
volumetric flask. Wash the filter paper two or three times with
TEST METHOD B—ATOMIC ABSORPTION—
water and adjust the filtrate to about 100 mL.
DIRECT
13.5 Add 2 drops of bromophenol blue indicator solution
16. Scope
and mix.
13.6 Adjust the pH by addition of NaOH solution (100 g/L) 16.1 This test method covers the determination of dissolved
until a blue color persists. Add HCl (1 + 49) by drops until the
and total recoverable silver in most waters, and wastewaters.
blue color just disappears; then add 2.5 mL of HCl (1 + 49) in 16.2 This test method is applicable in the range from 0.1 to
excess. The pH at this point should be 2.3.
10 mg/L of silver. The range may be extended by dilution of
the original sample.
NOTE 8—The pH adjustment in 13.6 may be made with a pH meter
16.3 This test method has been used successfully with
instead of using indicator.
reagent water, natural surface water and ground waters, an
13.7 Add 2.5 mL of APDC solution and mix. The pH should
industrial outfall, and a brine. The information on precision and
be approximately 2.8.
bias may not apply to other waters. It is the user’s
13.8 Add 10.0 mL of MIBK and shake vigorously for 1 min.
responsibility to ensure the validity of this test method for
waters of untested matrices.
NOTE 9—Warning: Perform in a well ventilated hood (see Note 3).
13.9 Allow the layers to separate and add, carefully down
17. Summary of Test Method
the side of the flask, water unt
...
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