ASTM D4517-04

Standard Test Method for Low-Level Total Silica in High-Purity Water by Flameless Atomic Absorption Spectroscopy

SIGNIFICANCE AND USE
Control of silica in boiler feedwater and boiler water is necessary to minimize the formation of scale-forming silicates that decrease heat transfer in the boiler. Volatilization and carryover of silica with the steam may cause hard, glassy siliceous deposits to form on turbine blades that reduce turbine efficiency.
Colloidal silica that is not removed by boiler water pretreatment processes may be solubilized in the boiler and thus contribute to the dissolved silica concentration in the boiler. Both dissolved and total silica are of interest.
SCOPE
1.1 This test method covers the determination of total silica in water.  
1.2 This test method is applicable in the range from 25 to 250 [mu]g/L of silica as SiO . Higher concentrations may be determined by decreasing the aliquot volume (see Note 6). Concentration range should not be extended by dilution.  
1.3 This test method determines total silica, and does not distinguish between soluble and insoluble forms.  
1.4 This test method was tested on reagent water only. It is the user's responsibility to assure the validity of the test method for waters of other matrices.  
1.5 This standard does not purport to address 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.

General Information

• Status: Historical
• Publication Date: 30-Apr-2004
• ICS: 71.060.20 - Oxides
• Technical Committee: D19 - Water
• Drafting Committee: D19.03 - Sampling Water and Water-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water

Relations

• Replaces: ASTM D4517-85(1999) - Standard Test Method for Low-Level Total Silica in High-Purity Water by Flameless Atomic Absorption Spectroscopy
• Effective Date: 01-May-2004
• Replaced By: ASTM D4517-04(2009) - Standard Test Method for Low-Level Total Silica in High-Purity Water by Flameless Atomic Absorption Spectroscopy
• Effective Date: 01-Oct-2009
• Referred By: ASTM D1193-06(2018) - Standard Specification for Reagent Water
• Effective Date: 01-May-2004
• Referred By: ASTM G90-23 - Standard Practice for Performing Accelerated Outdoor Weathering of Materials Using Concentrated Natural Sunlight
• Effective Date: 01-May-2004
• Referred By: ASTM D4364-13(2022)e1 - Standard Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight
• Effective Date: 01-May-2004
• Referred By: ASTM D7869-17 - Standard Practice for Xenon Arc Exposure Test with Enhanced Light and Water Exposure for Transportation Coatings
• Effective Date: 01-May-2004
• Referred By: ASTM D7356/D7356M-19 - Standard Test Method for Accelerated Acid Etch Weathering of Automotive Clearcoats Using a Xenon-Arc Exposure Device
• Effective Date: 01-May-2004
• Referred By: ASTM D5127-13(2018) - Standard Guide for Ultra-Pure Water Used in the Electronics and Semiconductor Industries
• Effective Date: 01-May-2004

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:D4517– 04
Standard Test Method for
Low-Level Total Silica in High-Purity Water by Flameless
1
Atomic Absorption Spectroscopy
This standard is issued under the fixed designation D4517; 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.
1. Scope* D3919 Practice for Measuring Trace Elements in Water by
Graphite Furnace Atomic Absorption Spectrophotometry
1.1 This test method covers the determination of total silica
D4453 Practice for Handling of Ultra-Pure Water Samples
in water.
D5810 Guide for Spiking into Aqueous Samples
1.2 This test method is applicable in the range from 25 to
D5847 Practice for Writing Quality Control Specifications
250 µg/L of silica as SiO . Higher concentrations may be
2
for Standard Test Methods for Water Analysis
determined by decreasing the aliquot volume (see Note 6).
Concentration range should not be extended by dilution.
3. Terminology
1.3 This test method determines total silica, and does not
3.1 Definitions—For definitions of terms used in this test
distinguish between soluble and insoluble forms.
method, refer to Terminology D1129.
1.4 This test method was tested on reagent water only. It is
the user’s responsibility to assure the validity of the test
4. Summary of Test Method
method for waters of other matrices.
4.1 Total silica is determined using an atomic absorption
1.5 This standard does not purport to address the safety
spectrophotometer in conjunction with a graphite furnace. A
concerns, if any, associated with its use. It is the responsibility
sample is placed in a graphite tube, evaporated to dryness,
of the user of this standard to establish appropriate safety and
charred, and atomized. Since the graphite furnace uses the
health practices and determine the applicability of regulatory
sample much more efficiently than flame atomization, the
limitations prior to use.
detection of low concentrations of elements in small sample
2. Referenced Documents volumes is possible. Finally, the absorption signal during
2 atomization is recorded and compared to standards. A general
2.1 ASTM Standards:
guide for the application of the graphite furnace is given in
D859 Test Method for Silica in Water
Practice D3919. Pretreatment of the graphite tube may be used
D1066 Practice for Sampling Steam
5
3 toenhancethesensitivityandrepeatability,orboth,ofthetest.
D1129 Terminology Relating to Water
4.2 Total silica is determined using a freshly ultrasonically
D1192 Guide for Equipment for SamplingWater and Steam
4 treated and shaken aliquot of sample.
in Closed Conduits
4.3 This test method determines low-level total silica in
D1193 Specification for Reagent Water
high purity water. Refer to Test Method D859, Method B, for
D2777 Practice for Determination of Precision and Bias of
determination of molybdate-reactive silica.
Applicable Test Methods of Committee D19 on Water
D3370 Practices for Sampling Water from Closed Conduits
5. Significance and Use
5.1 Control of silica in boiler feedwater and boiler water is
necessary to minimize the formation of scale-forming silicates
1
This test method is under the jurisdiction of ASTM Committee D19 on Water
that decrease heat transfer in the boiler. Volatilization and
and is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
carryover of silica with the steam may cause hard, glassy
Water-Formed Deposits, Surveillance of Water, and Flow Measurement of Water.
siliceous deposits to form on turbine blades that reduce turbine
Current edition approved May 1, 2004. Published May 2004. Originally
approved in 1985. Last previous edition approved in 1985 as D4517 – 85 (1999). efficiency.
DOI: 10.1520/D4517-04.
5.2 Colloidal silica that is not removed by boiler water
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
pretreatment processes may be solubilized in the boiler and
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 5
Withdrawn. Rawa, JudithA. and Earl L. Henn, “Determination of Trace Silica in Industrial
4
Withdrawn. The last approved version of this historical standard is referenced Process Waters by Flameless Atomic Absorption Spectrometry,” Analytical Chem-
on www.astm.org. istry, Vol 51, March 1979.
*A Summary of Changes section appears at the end of this standard.
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D4517– 04
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