ASTM D2331-80(2003)
(Practice)Standard Practices for Preparation and Preliminary Testing of Water-Formed Deposits
Standard Practices for Preparation and Preliminary Testing of Water-Formed Deposits
SIGNIFICANCE AND USE
Deposits in piping from aqueous process streams serve as an indicator of fouling, corrosion or scaling. Rapid techniques of analysis are useful in identifying the nature of the deposit so that the reason for deposition can be ascertained.
Possible treatment schemes can be devised to prevent deposition from reoccurring.
Deposits formed from or by water in all its phases may be further classified as scale, sludge, corrosion products or biological deposits. The overall composition of a deposit or some part of a deposit may be determined by chemical or spectrographic analysis; the constituents actually present as chemical substances may be identified by microscope or
X ray.
SCOPE
1.1 These practices provide directions for the preparation of the sample for analysis, the preliminary examination of the sample, and methods for dissolving the analytical sample or selectively separating constituents of concern.
1.2 The general practices given here can be applied to analysis of samples from a variety of surfaces that are subject to water-formed deposits. However, the investigator must resort to individual experience and judgement in applying these procedures to specific problems.
1.3 The practices include the following:SectionsPreparation of the Analytical Sample8Preliminary Testing of the Analytical Sample9Dissolving the Analytical Sample10
1.4 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 warning statement, see Note 2.
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Standards Content (Sample)
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Designation:D 2331–80 (Reapproved 2003)
Standard Practices for
Preparation and Preliminary Testing of Water-Formed
Deposits
This standard is issued under the fixed designation D 2331; 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 1128 Method for Identification of Types of Microorgan-
isms and Microscopic Matter in Water and Waste Water
1.1 These practices provide directions for the preparation of
D 1129 Terminology Relating to Water
the sample for analysis, the preliminary examination of the
D 1193 Specification for Reagent Water
sample, and methods for dissolving the analytical sample or
D1245 PracticeforExaminationofWater-FormedDeposits
selectively separating constituents of concern.
by Chemical Microscopy
1.2 The general practices given here can be applied to
D 2332 Practice forAnalysis of Water-Formed Deposits by
analysis of samples from a variety of surfaces that are subject
Wavelength-Dispersive X-Ray Fluorescence
to water-formed deposits. However, the investigator must
E11 Specification for Wire Cloth Sieves for Testing Pur-
resorttoindividualexperienceandjudgementinapplyingthese
poses
procedures to specific problems.
1.3 The practices include the following:
3. Terminology
Sections
3.1 Definitions—For definitions of terms used in these
Preparation of the Analytical Sample 8
Preliminary Testing of the Analytical Sample 9
practices, refer to Terminology D 1129.
Dissolving the Analytical Sample 10
4. Significance and Use
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.1 Deposits in piping from aqueous process streams serve
as an indicator of fouling, corrosion or scaling. Rapid tech-
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- niques of analysis are useful in identifying the nature of the
deposit so that the reason for deposition can be ascertained.
bility of regulatory limitations prior to use. For a specific
warning statement, see Note 2. 4.2 Possible treatment schemes can be devised to prevent
deposition from reoccurring.
2. Referenced Documents
4.3 Deposits formed from or by water in all its phases may
2.1 ASTM Standards: be further classified as scale, sludge, corrosion products or
D 887 Practices for Sampling Water-Formed Deposits biological deposits. The overall composition of a deposit or
D 932 Test Method for Iron Bacteria in Water and Water- some part of a deposit may be determined by chemical or
Formed Deposits spectrographic analysis; the constituents actually present as
D 933 Practice for Reporting Results of Examination and chemical substances may be identified by microscope or
Analysis of Water-Formed Deposits X ray.
D 934 Practices for Identification of Crystalline Com-
5. Reagents and Materials
pounds in Water-Formed Deposits by X-Ray Diffraction
5.1 Purity of Reagents—Reagent grade chemicals shall be
D 993 Test Method for Sulfate-Reducing Bacteria in Water
and Water-Formed Deposits used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to specifications of the Committee
on Analytical Reagents of the American Chemical Society,
1 4
These practices are under the jurisdiction of ASTM Committee D19 on Water
where such specifications are available. Other grades may be
and are the direct responsibility of Subcommittee D19.03 on Sampling ofWater and
used, provided it is first ascertained that the reagent is of
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
On-Line Water Analysis, and Surveillance of Water.
Current edition approved July 3, 1980. Published September 1980. Originally
approved in 1965. Last previous edition approved in 1980 as D 2331 – 80. Reagent Chemicals, American Chemical Society Specifications, American
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Chemical Society, Washington, DC. For suggestions on the testing of reagents not
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM listed by the American Chemical Society, see Analar Standards for Laboratory
Standards volume information, refer to the standard’s Document Summary page on Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
the ASTM website. and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
Withdrawn. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2331–80 (2003)
sufficiently high purity to permit its use without lessening the loss in weight of the thimble and contents, dried at 105°C, as
accuracy of the determination. chloroform-extracted matter. If important to the solution of the
5.2 Purity of Water—Unless otherwise indicated, references problem, evaporate the solvent, and examine the residue.
to water shall be understood to mean Type II reagent water 7.5.2 The extraction may be repeated with other volatile
conforming to Specification D 1193. organic solvents if exploratory tests warrant such procedure.
7.6 Pulverizing—Whether the sample is dry as received,
6. Sampling
air-dried or air-dried extracted, it must be pulverized to
6.1 Collect and preserve the sample in accordance with
adequate homogeneity. Grind the entire sample, or enough of it
Practices D 887.
to be representative of the whole, to pass a No. 100 (150-µm)
sieve, as specified in SpecificationE11. Continue the grinding
7. Preparation of Analytical Sample
until all the material passes through the sieve, except for
7.1 Preliminary Examination—Examine the sample as col-
fragments such as splinters of fiber, wood, and metal.
lected, using a microscope if available, for structure, color,
7.6.1 Identify fragments separated from the sample during
odor, oily matter, appearance of mother liquor if any, and other
grinding by standard methods if this information is valuable.
characteristics of note (for example, attraction to magnet).
7.6.2 Mix the sieved material thoroughly by tumbling in a
Record results for future reference.
closed dry container that is no more than two thirds full.
7.1.1 Filtration and other steps in the preparation of the
7.6.3 Transfer 5 to 10 g of the thoroughly mixed material to
analytical sample may frequently be bypassed; for example, a
a weighing bottle. This is the analytical sample. Unless the
moist sample that contains no separated water shall be started
determinations are to be made on an air-dried basis, dry at
in accordance with 7.3.1, and a dry sample shall be started in
105°C and store in a desiccator.
accordance with 7.4, 7.5,or 7.6. Partitioning, 7.4, is not always
practical or even desirable. Solvent extraction, 7.5, is unnec- 8. Preliminary Testing of Analytical Sample
essary if the sample contains no oily or greasy matter.
8.1 This section outlines methods for the preliminary ex-
7.2 Filtration of Sample (see Note 1)—If the sample in-
amination of samples of water-formed deposits. Use one or
cludes an appreciable quantity of separated water, remove the
more of these methods to disclose the component elements of
solid material by filtration. Save the filtrate, undiluted, pending
the sample and whether the concentrations are major, minor, or
decision as to whether or not its chemical examination is
trace, an essential guide to planning the analysis. This prelimi-
required. Transfer all of the solid portion to the filter, using the
nary testing frequently also provides important guidance to-
filtrate to rinse the sample container if necessary.Air-drying or
ward defining technological problems associated with the
partial air-drying of the filter is frequently helpful toward
occurrence of the deposits. The methods include spectrogra-
effecting a clean separation of the deposit.
phy, atomic absorption spectrophotometry, X-ray diffraction,
X-ray fluorescence, microscopy, and ordinary qualitative
NOTE 1—If the sample obviously contains oily matter, its extraction
analysis.
with a suitable solvent (see 7.5) is essential before filtration or air-drying
is attempted. Likewise, if the sample is suspected to contain easily 8.2 Spectrography—Make the spectrographic analysis by a
oxidizablematerials,suchassulfide,analysisforthesematerialsshouldbe
suitable method, for example, as outlined in 8.2.2 to 8.2.7.
completed before air-drying.
8.2.1 Although superior results are obtainable with a spec-
7.3 Air-Drying—Remove the drained solid sample from the trograph and associated equipment, data of lesser degree of
filter, being careful to avoid gross contamination with filter accuracy can frequently be obtained with less formal equip-
paper. ment such as a visual-arc spectroscope.
7.3.1 Air-dry the entire quantity of solid, spread in a thin 8.2.2 For best results use a spectrograph having a suitable
layer on a nonreactive, impervious surface.Arecord of the loss reciprocal linear dispersion, associated adjuncts and optics, a
of weight during air-drying is often used. microphotometer for measuring the transmittances of spectra-
7.4 Partitioning the Sample—Many samples are obviously line images, and associated equipment for determining inten-
heterogeneous. If useful to explain the occurrence of the sity ratios.
water-formed deposit, separate clearly defined layers or com- 8.2.3 Mix 50 mg of the pulverized sample, obtained in
ponents, and approximate the relative percentages. accordance with 7.6.2, with 900 mg of graphite powder and
7.4.1 Retain the individual air-dried fractions for separate 250 mg of lithium carbonate. Pack the mixture into graphite-
analysis, preferably storing over an effective desiccant such as cup electrodes.
anhydrite. 8.2.4 Record the spectra obtained upon excitation with a d-c
7.5 Solvent Extraction—This step is essential only if the arc.
air-dried sample smears or agglomerates when tested for 8.2.5 Measure the transmittances of the analytical and
pulverization (smears caused by graphite are possible but rare lithium lines (internal standards other than lithium are pre-
with water-formed deposits). ferred by some operators). Determine intensity ratios from
7.5.1 Weighnomorethan10gofair-driedsampleandplace these data.
this, wrapped in fine-textured filter paper, in a prepared 8.2.6 Use the intensity ratios to estimate concentrations
(extractedanddried)Soxhletthimble.Paperclipsareusefulfor from standard analytical curves.
preventing unfolding of the paper. Weigh the thimble and its 8.2.7 The metallic constituents can frequently be deter-
contents and extract in a Soxhlet apparatus until the solvent mined within 20 % of their content in the deposit, which is
(chloroform) in the extraction chamber is colorless. Record the sufficiently close for classification as major, minor, or trace.
D 2331–80 (2003)
8.3 Atomic Absorption—Make the atomic absorption analy- 8.4 X-Ray Diffraction—PerformtheX-raydiffractionanaly-
sis in accordance with appropriate method. sis in accordance with Practices D 934.
8.3.1 The required apparatus shall include an atomizer and
8.4.1 The required apparatus shall include a radiation
burner, suitable pressure-regulating devices, a multielement source, of which more than one may be needed, a camera or
hollow-cathode lamp (alternatively, a hollow-cathode lamp for
other device for sensing or recording radiation intensity, and
each metal to be tested), an optical system capable of isolating
adjuncts for interpreting the recorded data.
the desired wavelengths of radiation as lines, and adjuncts for
8.4.2 Regrind a portion of the pulverized sample, obtained
obtaining amplified measurements and readout.
in accordance with 7.6.2, to pass a No. 270 (53-µm) sieve (or
8.3.2 Prepare standards as in the selected or multiple stan-
as directed by a specific manufacturer). Mount the powdered
dards if a multielement is used. Follow the manufacturer’s
material in the shape or form required for the sensing device
recommendations for instrument start-up and optimization of
that is used.
test conditions. Calibrate the instrument for each element to be
8.4.3 Record the diffraction pattern on photographic film, or
determined by aspirating prepared standard solutions and
its equivalent while the mounted sample is exposed to the
noting the corresponding instrument read out.Aspirate a blank
X-ray beam for the required interval.
solution between each standard to assure instrument stability.
8.4.4 The radiation pattern shall be translated into lines and
Each element absorbs energy from the line source at a
intensities, using the adjuncts available for this purpose, and
characteristic wavelength which results in a decrease in energy
these shall be compared with standard diffraction patterns for
noted at the detector. Record the instrument readings, and plot
known compounds.
against the occurrence of the absorbing atom in milligrams per
8.4.5 Identification of a substance is made when sufficient
litre of the aspirated solution.
characteristic lines of a standard pattern occur in the pattern
8.3.3 Prepare the solubilized sample (9.2, 9.3,or 9.4,
derived from the sample, in essentially the same relative
depending on the solubility of the water-formed deposit).
intensity. However, owing to the poor crystallization charac-
Using volumetric flasks, make 100 mL each of the two
teristic of many water-formed deposits, the sensitivity of this
dilutions, 1 + 9 and 1 + 99, by adding enough water to 10 and
evaluation is often much poorer than the 1 percent usually
1 mL of the solubilized sample, respectively.
cited.
8.3.4 Aspirate the solubilized sample and the two dilutions
8.5 X-Ray Fluorescence—Perform the X-ray fluorescence
prepared from it, aspirating water before going from one
analysis in accordance with Practice D 2332.
dilution to another. Record the instrument readings for the
8.5.1 The required apparatus shall include sample prepara-
wavelengths of interest.
tion equipment, excitation source, devices for housing the
8.3.5 Determine the concentration of each metal tested in
sample, a spectrometer assembly, and adjuncts for obtaining
each dilution of the solubilized sample by referring the
and interpreting data.
absorbance obtained to a prepared calibration curve that relates
8.5.2 Regrind the pulverized sample obtained in accordance
the concentration of prepared standard solutions and their
corresponding absorbances. Alternatively, when direct readout with 7.6.2 to pass a No. 270 (53-µm) sieve. For order of
in terms of concentrati
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