ASTM D1245-84(2003)
(Practice)Standard Practice for Examination of Water-Formed Deposits by Chemical Microscopy
Standard Practice for Examination of Water-Formed Deposits by Chemical Microscopy
SIGNIFICANCE AND USE
Chemical composition of water-formed deposits is a major indicator of proper or improper chemical treatment of process water, and is often an indicator of operational parameters as well, for example, temperature control. This practice allows for rapid determination of constituents present in these deposits, particularly those indications of improper water treatment, since they usually have very distinctive and easily recognized optical properties.
This practice, where applicable, eliminates the need for detailed chemical analysis, which is time-consuming, and which does not always reveal how cations and anions are mutually bound.
Qualitative use of this practice should be limited to those deposits whose control is generally known or predictable, based on treatment and feedwater mineral content, and whose constituents are crystalline, or in other ways optically or morphologically distinctive. If these criteria are not met, other techniques of analysis should be used, such as Practice D 2332 or Test Methods D 3483, or both.
Quantitative use of this practice should be limited to estimates only. For more precise quantitative results, other methods should be used (see 5.3).
SCOPE
1.1 This practice describes a procedure for the examination of water-formed deposits by means of chemical microscopy. This practice may be used to complement other methods of examination of water-formed deposits as recommended in Practices D2331 or it may be used alone when no other instrumentation is available or when the sample size is very small.
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.
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An American National Standard
Designation:D 1245–84 (Reapproved 2003)
Standard Practice for
Examination of Water-Formed Deposits by Chemical
Microscopy
This standard is issued under the fixed designation D 1245; 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 3.2 Descriptions of Terms Specific to This Standard
—Certain terms in this practice that relate specifically to
1.1 This practice describes a procedure for the examination
chemical microscopy are described as follows:
of water-formed deposits by means of chemical microscopy.
3.2.1 anisotropic—having different optical properties in
This practice may be used to complement other methods of
different optical planes. These planes are referred to as the
examination of water-formed deposits as recommended in
alpha, beta, and omega axes.
Practices D 2331 or it may be used alone when no other
3.2.2 Becke line—a faint, halo-like line that surrounds a
instrumentation is available or when the sample size is very
crystal when the crystal is mounted in an oil of different
small.
refractiveindex.Itincreasesinintensityasthedifferenceinthe
1.2 This standard does not purport to address all of the
refractive index between the crystal and the oil increases.
safety concerns, if any, associated with its use. It is the
3.2.3 dispersion—the variation of index of refraction with
responsibility of the user of this standard to establish appro-
wavelength.
priate safety and health practices and determine the applica-
3.2.4 dispersion staining—the color effects produced when
bility of regulatory limitations prior to use.
a transparent object, immersed in a liquid having a refractive
2. Referenced Documents
indexnearthatoftheobjectisviewedunderthemicroscopeby
transmitted white light and precise aperture control.
2.1 ASTM Standards:
3.2.5 extinction angle—the angle between the extinction
D 887 Practices for Sampling Water-Formed Deposits
position and some plane, edge, or line in a crystal.
D 1129 Terminology Relating to Water
3.2.6 extinction position—the position in which an aniso-
D 1193 Specification for Reagent Water
tropic crystal, between crossed polars, exhibits complete dark-
D 2331 Practices for Preparation and PreliminaryTesting of
ness.
Water-Formed Deposits
3.2.7 index of refraction—the numerical expression of the
D 2332 Practice for Analysis of Water-Formed Deposits by
ratio of the velocity of light in a vacuum to the velocity of light
Wavelength-Dispersive X-Ray Fluorescence
in a substance.
D 3483 Test Methods for Accumulated Deposition in a
3.2.8 isotropic—having the same optical properties in all
Steam Generator Tube
directions.
3. Terminology
3.2.9 petrographic—pertaining to the description of rocks
or rocklike substances. Such description is usually in terms of
3.1 Definitions—For definitions of terms in this practice
morphology and optical properties.
relating specifically to water and water-formed deposits, refer
3.2.10 solid solution—a homogeneous mixture of two or
to Terminology D 1129.
more components, in the solid state, retaining substantially the
structure of one of the components.
This practice is under the jurisdiction of ASTM Committee D19 on Water and
is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
On-Line Water Analysis, and Surveillance of Water.
Current edition approved Oct. 26, 1984. Published February 1985. Originally
approved in 1952. Last previous approved in 1984 as edition D 1245 – 84.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 1245–84 (2003)
4. Summary of Practice 7.6 Micro Gas Burner.
7.7 Micro Spatula.
4.1 The practice is essentially chemical microscopical,
7.8 Microscope Slides, of selected grade, 25.4 by 76.2 or
supplemented by optical data obtained by the petrographic
25.4 by 50.8 mm (1 by 3 or 1 by 2 in.).
method. The identification of compounds is made by observ-
7.9 Mortar and Pestle, of tool steel, mullite, or aluminum
ing, under the microscope, characteristic reactions and precipi-
oxide.
tates resulting from the action of specific reagents on the solid
7.10 Petrographic Microscope—A microscope equipped
sample or solutions thereof, and by measuring the optical
with a circular rotating stage, graduated in degrees.The optical
properties.
system shall include two polarizing devices, one mounted
below the condenser and the other just above the objective;
5. Significance and Use
43,103, and 453 objectives; and 53 and 103 eyepieces
5.1 Chemical composition of water-formed deposits is a
fitted with crosshairs.The optic axis of the microscope shall be
major indicator of proper or improper chemical treatment of
adjustable so that it can be brought into coincidence with the
process water, and is often an indicator of operational param-
centerofrotationoftherevolvingstage.ABertrand-Amicilens
eters as well, for example, temperature control. This practice
equipped with an iris diaphragm, or a sliding stop ocular, shall
allows for rapid determination of constituents present in these
be used for viewing interference figures. A quartz wedge,
deposits, particularly those indications of improper water
gypsum plate, and standard mica plate are necessary external
treatment, since they usually have very distinctive and easily
accessories. Aperture stops are necessary for observing the
recognized optical properties.
color effects of dispersion, that is, dispersion staining. A
5.2 This practice, where applicable, eliminates the need for
cardboard “washer” in the objective and a cover glass with a
detailed chemical analysis, which is time-consuming, and
centered dried drop of India ink are sufficient; however, a
which does not always reveal how cations and anions are
device is available commercially.
mutually bound.
7.11 Porcelain Crucibles, No. 0.
5.3 Qualitative use of this practice should be limited to
7.12 Reagent Bottles for Immersion Liquids—Glass drop-
thosedepositswhosecontrolisgenerallyknownorpredictable,
ping bottles of 30-mLcapacity.These bottles shall be equipped
based on treatment and feedwater mineral content, and whose
with groundglass stoppers with dropping rods integral with the
constituents are crystalline, or in other ways optically or
stoppers. Inert plastic bulbs and caps may be used, but
morphologically distinctive. If these criteria are not met, other
dropping bottles with rubber bulbs are unsatisfactory because
techniques of analysis should be used, such as Practice D 2332
of the effect of some of the immersion liquids on the rubber. It
or Test Methods D 3483, or both.
is essential that the bottles be marked with the refractive index
5.4 Quantitative use of this practice should be limited to
of the contained liquid. Commercially available liquids come
estimates only. For more precise quantitative results, other
in dropping bottles which are acceptable.
methods should be used (see 5.3).
7.13 Refractometer, for measuring the refractive index of
immersion liquids.
6. Interferences
7.14 Sample Vials, 45 by 15-mm.
6.1 Organic material may interfere with both the petro-
7.15 Sieve, No. 100 (149 µm).
graphic and the chemical procedures. Organics can usually be
7.16 Small Alloy Magnet.
removed by solvent extraction as recommended in Practice
D 2331.
8. Reagents
6.2 Deposits containing solid solutions present a complica-
8.1 Purity of Reagents—Reagent grade chemicals shall be
tion in that optical data vary throughout such a system, and
used in all tests. Unless otherwise indicated, it is intended that
unlessthepresenceofthiscomplicationisknown,thedatamay
all reagents shall conform to the specifications of the Commit-
be misinterpreted.
tee onAnalytical Reagents of theAmerican Chemical Society,
6.3 Extremelyfinematerialandopaquematerialaredifficult 3
where such specifications are available. Other grades may be
to identify. When present in appreciable amounts they may
used, provided it is first ascertained that the reagent is of
cloud over and obscure details of otherwise recognizable
sufficiently high purity to permit its use without lessening the
particles.
accuracy of the determination.
6.4 Interference with the chemical tests will be discussed in
8.1.1 Unless otherwise indicated, references to water shall
the procedures.
be understood to mean reagent water conforming to Specifi-
cation D 1193, Type II.
7. Apparatus
8.2 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
7.1 Beakers, 30-mL, borosilicate glass.
monium hydroxide (NH OH).
7.2 Cover Glasses, No. 1 or No. 1 ⁄2 thickness, round or
square cover glasses.
7.3 Glass Rods, 150 by 5 mm for transferring drops, and 75
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
by 1 mm for stirring and leading reagent drops on the slides.
listed by the American Chemical Society, see Analar Standards for Laboratory
7.4 Hotplate.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
7.5 Light Source—Microscope lamp with concentrated fila-
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
ment bulb and a focusing lens. MD.
D 1245–84 (2003)
8.3 Ammonium Molybdate Solution (100 g/L)—Dissolve 1 8.25 Zinc Dust—Powdered zinc metal.
g of ammonium molybdate ((NH ) Mo O ·4H O) in water, 8.26 Zinc Uranyl Acetate Solution—Dissolve1gof uranyl
4 6 7 24 2
add 35 mL of nitric acid HNO (sp gr 1.42) and dilute to 1 L
acetate UO (C H O ) ·2H O and 0.1 mL of glacial acetic acid
3 2 2 3 2 2 2
with water. in 5 mL of water. Dissolve3gof zinc acetate
8.4 Ammonium Persulfate —((NH ) S O ), crystalline.
Zn(C H O ) ·2H O and 0.1 mL of glacial acetic acid in 5 mL
4 2 2 8
2 3 2 2 2
8.5 Barium Chloride Solution (100 g/L)—Dissolve 100 g of of water. Warm if necessary to complete solution. Mix the two
barium chloride (BaCl ·2H O) in water and dilute to 1 L.
solutions and store in a chemically resistant glass bottle. If
2 2
8.6 Cesium Sulfate—Cs SO crystals, 10 to 20-mesh. precipitation occurs, filter the solution before use.
2 4
8.7 Chloroform.
8.8 Chloroplatinic Acid Solution—Dissolve1gof chloro- 9. Sampling
platinic acid H PtCl ·6H O in 5 mL of water and add 0.5 mL
2 6 2
9.1 Collect the sample in accordance with Practice D 887.
of HCl (sp gr 1.19).
8.9 Diammonium Phosphate Solution (100 g/L)—Dissolve
10. Laboratory Preparation of Samples
100 g of diammonium phosphate (NH ) HPO in water and
4 2 4
10.1 Prepare the sample in accordance with Practice
dilute to 1 L.
D 2331.
8.10 Dimethylglyoxime, crystalline.
10.2 Place a portion of the ground sample (approximately
8.11 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
0.1 g or less) in a porcelain crucible, add 4 drops of HNO (sp
chloric acid (HCl). 3
gr 1.42), and evaporate to dryness over the microburner.Add 1
8.12 HydrochloricAcid(1+4)—Mix1volumeofHCl(spgr
mL of water, warm, and stir with a glass rod. Allow the
1.19) with 4 volumes of water.
insoluble material to settle. Withdraw portions of the superna-
8.13 Lead Acetate Test Paper.
tant liquid, henceforth referred to as the test solution, on the
8.14 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
endofaglassrodandtransfertoaslideforcarryingoutcertain
(HNO ).
of the tests described in Section 11.
8.15 Nitric Acid (1+19)—Mix 1 volume of HNO (sp gr
1.42) with 10 volumes of water.
11. Chemical Procedures
8.16 Phenolphthalein Indicator Solution.
8.17 Potassium Ferricyanide [K Fe(CN) ], crystalline.
11.1 The tests in this section are intended as an aid to the
3 6
8.18 Potassium Iodide (KI), crystalline.
petrographic section of this practice. The sensitivity of these
8.19 Potassium Mercuric Thiocyanate Solution (100 g/L)—
tests varies so that the operator should become familiar with
Prepare freshly precipitated mercuric thiocyanate Hg(CNS)
each test to be able to judge semiquantitatively the amount of
by adding a concentrated solution of mercuric nitrate each constituent present based on the amount of sample used
Hg(NO ) to a concentrated solution of potassium thiocyanate
and the strength of the reaction observed. Some of these tests
3 2
KCNS.Filterandair-drytheprecipitate.ToonepartHg(CNS) may not be necessary if spectrographic or X-ray diffraction
add three parts KCNS, dissolve in a minimum quantity of
equipmentorbothareavailable.Foramoredetaileddiscussion
water, and evaporate in a desiccator. Collect the first crop of
of these tests refer to Chamot and Mason (3) or to Feigl (6).
tabular crystals of potassium mercuric thiocyanate
11.2 Evolution of Gas with Dilute Acid—Place a portion of
K Hg(CNS) , wash with alcohol, and dry. Dissolve 10 g of the
the ground deposit on a slide and allow a drop of HCl (1+4) to
2 4
crystals in water and dilute to 100 mL.
flow into it. Observe macroscopically or under the 43 objec-
8.20 Refractive Index Standards—A set of liquids having
tive for evolution of gas bubbles which indicates that presence
refractive indices ranging from 1.40 to 1.74 in steps of 0.01. In
of carbonates, sulfites, sulfides, nitrites, or metals. Effereve-
the range from 1.45 to 1.65, it is desirable to have liquids
scense due to carbonates is usually violent and of short
available in steps of 0.005. Commercially available liquids are
duration.Thegasevolutionduetosulfites,nitrites,andsulfides
recommended; however directions for the preparation of suit-
is usually less vigorous and there is a characteristic odor of the
able liquids are given in U. S. Geological Survey Bulletin No.
gas. Evolution of hydrogen gas from a metal is usually of
848 (1) or Elements of Optical Mineralogy (2). The index of
considerable duration. Dry and examine the slide used for this
refractionoftheseliquidsmustbecheckedpriortotheiruse,as
test. If sodium salts are present, cubic crystals of sodium
they may change from loss of more volatile constituents.
chloride will be formed. If appreciable amounts of calcium and
8.21 Silver Nitrate Solution (50 g/L)—Dissolve 50 g of
sulfate ions were present, characteristic clumps of
silver nitrateAgNO in water, add 20 mLof HNO (sp gr 1.42),
CaSO ·2H O needles will be formed.
3 3
4 2
and dilute to 1 L with water.
11.3 Ma
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