ASTM D4192-03

Standard Test Method for Potassium in Water by Atomic Absorption Spectrophotometry

SIGNIFICANCE AND USE
Potassium occurs in rocks in a form that is not easily solubilized; therefore, the potassium content of natural waters is usually low. Most natural waters contain less than 20 mg/L of potassium, but waters containing several hundred milligrams per litre are occasionally found. Potassium is essential to animal nutrition, but a concentration of 1000 to 2000 mg/L in stock water is regarded as the extreme limit permissible.
SCOPE
1.1 This test method covers the determination of low amounts of potassium in waters having low solids content. The applicable range of this test method is 0.20 to 4.0 mg/L when using the 766.5-nm resonance line. The range may be extended upward by dilution of an appropriate aliquot of sample or by using the less-sensitive 404.4-nm resonance line. Many workers have found that this test method is reliable for potassium levels to 0.02 mg/L, but use of this test method at this low level is dependent on the configuration of the aspirator and nebulizer systems available in the atomic absorption spectrophotometer as well as the skill of the analyst. The precision and bias data presented are insufficient to justify use of this test method in the 0.02-mg/L range.
1.2 This test method has been used successfully with spiked reagent water. It is the analyst's responsibility to ensure the validity of this test method to other low dissolved solids matrices.
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. For a specific precautionary statement, see Note 3.

General Information

• Status: Historical
• Publication Date: 09-Jan-2003
• 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 D4192-97 - Standard Test Method for Potassium in Water by Atomic Absorption Spectrophotometry
• Effective Date: 10-Jan-2003
• Replaced By: ASTM D4192-08 - Standard Test Method for Potassium in Water by Atomic Absorption Spectrophotometry
• Effective Date: 01-Oct-2008
• Referred By: ASTM D5127-13(2018) - Standard Guide for Ultra-Pure Water Used in the Electronics and Semiconductor Industries
• Effective Date: 10-Jan-2003
• Referred By: ASTM D8006-16 - Standard Guide for Sampling and Analysis of Residential and Commercial Water Supply Wells in Areas of Exploration and Production (E&P) Operations
• Effective Date: 10-Jan-2003
• Referred By: ASTM D1971-16(2021)e1 - Standard Practices for Digestion of Water Samples for Determination of Metals by Flame Atomic Absorption, Graphite Furnace Atomic Absorption, Plasma Emission Spectroscopy, or Plasma Mass Spectrometry
• Effective Date: 10-Jan-2003

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:D4192–03
Standard Test Method for
Potassium in Water by Atomic Absorption
1
Spectrophotometry
This standard is issued under the fixed designation D 4192; 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* D 2777 Practice for Determination of Precision and Bias of
3
Applicable Methods of Committee D-19 on Water
1.1 This test method covers the determination of low
2
D 3370 Practices for Sampling Water from Closed Con-
amounts of potassium in waters having low solids content.
3
duits
The applicable range of this test method is 0.20 to 4.0 mg/L
3
D 5810 Guide for Spiking into Aqueous Samples
when using the 766.5-nm resonance line. The range may be
D 5847 Practice for the Writing Quality Control Specifica-
extended upward by dilution of an appropriate aliquot of
3
tions for Standard Test Methods for Water Analysis
sample or by using the less-sensitive 404.4-nm resonance line.
Many workers have found that this test method is reliable for
3. Terminology
potassium levels to 0.02 mg/L, but use of this test method at
3.1 Definitions—For definitions of terms used in this test
this low level is dependent on the configuration of the aspirator
method, refer to Terminology D 1129.
and nebulizer systems available in the atomic absorption
spectrophotometer as well as the skill of the analyst. The
4. Summary of Test Method
precision and bias data presented are insufficient to justify use
4.1 Potassium is determined by flame atomic absorption
of this test method in the 0.02-mg/L range.
spectrophotometry. The potassium content is determined by
1.2 This test method has been used successfully with spiked
aspirating the low solids sample directly with no sample
reagent water. It is the analyst’s responsibility to ensure the
pretreatment.
validity of this test method to other low dissolved solids
matrices.
5. Significance and Use
1.3 This standard does not purport to address all of the
5.1 Potassium occurs in rocks in a form that is not easily
safety concerns, if any, associated with its use. It is the
solubilized; therefore, the potassium content of natural waters
responsibility of the user of this standard to establish appro-
is usually low. Most natural waters contain less than 20 mg/L
priate safety and health practices and determine the applica-
of potassium, but waters containing several hundred milli-
bility of regulatory limitations prior to use. For a specific
gramsperlitreareoccasionallyfound.Potassiumisessentialto
precautionary statement, see Note 3.
animal nutrition, but a concentration of 1000 to 2000 mg/L in
stock water is regarded as the extreme limit permissible.
2. Referenced Documents
2.1 ASTM Standards:
6. Interferences
3
D 1066 Practice for Sampling Steam
6.1 In the analysis of low-solids water, interferences are
3
D 1129 Terminology Relating to Water
usually negligible.
D 1192 Specification for Equipment for Sampling Water
3
and Steam in Closed Conduits
7. Apparatus
3
D 1193 Specification for Reagent Water
7.1 Atomic Absorption Spectrophotometer for use at 766.5
nm.
1
This test method is under the jurisdiction of ASTM Committee D19 on Water
NOTE 1—The manufacturer’s instructions should be followed for all
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
instrumental parameters. Wavelengths other than 766.5 nm may be used
in Water.
only if they have been determined to be equally suitable.
Current edition approved Jan. 10, 2003. Published January 2003. Originally
approved in 1982. Last previous edition approved in 1997 as D 4192–97.
7.2 Potassium Hollow-Cathode Lamps—Multielement hol-
2
Platte, J.A., and Marcy,V. M., “ANewTool for theWater Chemist,” Industrial
low cathode lamps are available and also have been found
Water Engineering, May 1965.
3
Annual Book of ASTM Standards, Vol 11.01. satisfactory.
*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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D4192–03
TABLE 1 Determination of Bias for Potassium in Reagent Water
7.3 Pressure-Reducing Valves—The supplies of fuel and
by Atomic Absorption
oxidant shall be maintained at pressures somewhat higher than
Amount Amount
the operating pressure of the instrument by using suitable
Added, Found, S S Bias %
t o
valves.
mg/L mg/L
0.15 0.164 0.037 0.014 + 9.33
8. Reagents and Materials
1.50 1.62 0.085 0.044 + 8.00
3.00 3.03 0.179 0.062 + 1.13
8.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwis
...