ASTM D4691-96

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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 4691 – 96
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 Practice for
Measuring Elements in Water by Flame Atomic Absorption
1
Spectrophotometry
This standard is issued under the fixed designation D 4691; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers general considerations for the
2
D 1129 Terminology Relating to Water
quantitative determination of elements in water and waste
D 1192 Specification for Equipment for Sampling Water
water by flame atomic absorption spectrophotometry. Flame
2
and Steam in Closed Conduits
atomic absorption spectrophotometry is simple, rapid, and
2
D 1193 Specification for Reagent Water
applicable to a large number of elements in drinking water,
2
D 2972 Test Methods for Arsenic in Water
surface waters, and domestic and industrial wastes. While
2
D 3223 Test Method for Total Mercury in Water
some waters may be analyzed directly, others will require
D 3370 Practices for Sampling Water from Closed Con-
pretreatment.
2
duits
2
1.2 Detection limits, sensitivity, and optimum ranges of the
D 3859 Test Methods for Selenium in Water
elements will vary with the various makes and models of
D 3919 Practice for Measuring Trace Elements in Water by
2
satisfactory atomic absorption spectrometers. The actual con-
Graphite Furnace Atomic Absorption Spectrophotometry
centration ranges measurable by direct aspiration are given in D 4453 Practice for Handling of Ultra-Pure Water
2
the specific test method for each element of interest. In the Samples
3
E 178 Practice for Dealing with Outlying Observations
majority of instances the concentration range may be extended
E 520 Practice for Describing Detectors in Emission and
lower by use of electrothermal atomization and conversely
4
Absorption Spectroscopy
extended upwards by using a less sensitive wavelength or
E 863 Practice for Describing Flame Atomic Absorption
rotating the burner head. Detection limits by direct aspiration
4
Spectroscopy Equipment
may also be extended through sample concentration, solvent
extraction techniques, or both. Where direct aspiration atomic
3. Terminology
absorption techniques do not provide adequate sensitivity, the
3.1 Definitions:
analyst is referred to Practice D 3919 or specialized procedures
3.1.1 For definition of terms used in this practice, refer to
such as the gaseous hydride method for arsenic (Test Methods
Terminology D 1129.
D 2972) and selenium (Test Methods D 3859), and the cold
3.2 Definitions of Terms Specific to This Standard:
vapor technique for mercury (Test Method D 3223).
3.2.1 absorbance, , n—the logarithm to the base 10 of the
1.3 Because of the differences among various makes and
reciprocal of the transmittance (T). A 5 log (1/T) 5 −log T.
10 10
models of satisfactory instruments, no detailed operating in-
3.2.2 absorptivity, , n—the absorbance (A) divided by the
structions can be provided. Instead the analyst should follow
produce of the sample path length (b) and the concentration (c).
the instructions provided by the manufacturer of a particular
a 5 A/bc.
instrument.
3.2.3 atomic absorption, , n—the absorption of electromag-
netic radiation by an atom resulting in the elevation of
1.4 This standard does not purport to address all of the
electrons from their ground states to excited states. Atomic
safety concerns, if any, associated with its use. It is the
absorption spectrophotometry involves the measurement of
responsibility of the user of this standard to establish appro-
light absorbed by atoms of interest as a function of the
priate safety and health practices and determine the applica-
concentration of those atoms in a particular solution.
bility of regulatory limitations prior to use. For specific hazard
3.2.4 detection limit, , n—a function of the sensitivity and
statements see Section 9.
the signal to noise ratio in the analysis of a specific element for
a given set of parameters. The detection limit is determined
1
This practice is under the jurisdiction of ASTM Committee D-19 on Water and
is the direct responsibility of Subcommittee D 19.05 on Inorganic Constituents in
2
Water. Annual Book of ASTM Standards, Vol 11.01.
3
Current edition approved Aug. 10, 1996. Published October 1996. Originally Annual Book of ASTM Standards, Vol 14.02.
4
published as D 4691–87. Last previous edition D 4691–87 (1992). Annual Book of ASTM Standards, Vol 03.06.
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