ASTM D5987-96(2007)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5987 − 96(Reapproved 2007)
Standard Test Method for
Total Fluorine in Coal and Coke by Pyrohydrolytic
Extraction and Ion Selective Electrode or Ion
Chromatograph Methods
This standard is issued under the fixed designation D5987; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope from As-Determined to Different Bases
D4621Guide for Quality Management in an Organization
1.1 This test method covers the analysis of total fluorine in
That Samples or Tests Coal and Coke (Withdrawn 2010)
coal and coke.
D5142Test Methods for ProximateAnalysis of theAnalysis
1.2 This analysis was successfully tested on coals contain-
Sample of Coal and Coke by Instrumental Procedures
ing 37% ash or less (see AS 1038.10.4 and Conrad ).
(Withdrawn 2010)
1.3 The values stated in SI units shall be regarded as 2.2 Australian Standard:
standard. The values given in parentheses are for information AS 1038.10.4Determination of Trace Elements—Coal,
only. Coke and Fly-Ash-Determination of Fluorine Content—
Pyrohydrolysis Method
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Summary of Test Method
responsibility of the user of this standard to establish appro-
3.1 Total fluorine is determined in this test method by first
priate safety and health practices and determine the applica-
subjecting the weighed test portion to pyrohydrolytic condi-
bility of regulatory limitations prior to use. For specific hazard
tions which separate fluorine from the coal/coke matrix. The
statements see Note 4.
pyrohydrolysate is then gravimetrically processed and final
1.5 All accountability and quality control aspects of Guide
determinations are made by either ion-selective electrode or
D4621 apply to this test method.
ion chromatographic techniques.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 This test method permits measurement of the fluorine
D346Practice for Collection and Preparation of Coke
contentofcoalandcokefortheevaluationofpotentialfluorine
Samples for Laboratory Analysis
emissionfromcoalcombustionorconversionprocesses.When
D1193Specification for Reagent Water
coal samples are combusted in accordance with this test
D2013Practice for Preparing Coal Samples for Analysis
method, the fluorine is quantitatively released from the coal
D2234/D2234MPractice for Collection of a Gross Sample
and retained in the pyrohydrolysate so that it is representative
of Coal
of the total fluorine concentration in coal.
D3174Test Method forAsh in theAnalysis Sample of Coal
and Coke from Coal
5. Apparatus
D3180Practice for Calculating Coal and Coke Analyses
5.1 Laboratory Ware—Except as noted, all laboratory ware,
for example, volumetric flasks, beakers, bottles, etc., used for
This test method is under the jurisdiction of ASTM Committee D05 on Coal
solutions containing fluoride ions must be made of
and Coke and is the direct responsibility of Subcommittee D05.29 on Major
polyethylene, polystyrene, or a heat-resistant polymer such as
Elements in Ash and Trace Elements of Coal.
polypropylene.
Current edition approved Oct. 1, 2007. Published October 2007. Originally
published approved in 1996. Last previous edition approved in 2002 as
5.2 Vials—Glass or polystyrene, 10 to 30-mLcapacity with
D5987–96(2002). DOI: 10.1520/D5987-96R07.
2 tightly fitting snap-on plastic lids.
Conrad, V. B., and Brownlee, W. D., “Hydropyrolytic—Ion Chromatographic
DeterminationofFluorideinCoalandGeologicalMaterials,” Analytical Chemistry,
Vol 60, No. 4, 1988, pp. 365–369.
3 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5987 − 96 (2007)
5.3 Bottles—Polypropylene, 125-mL capacity, wide-mouth, 5.8 Balance—Analytical, with a sensitivity of 0.1 mg. The
with liner-less leakproof polyethylene screw cap, for tube- balanceshallbecheckedperiodicallytodetermineitsaccuracy.
furnace pyrohydrolysate processing.
5.9 Apparatus for Tube-Furnace Pyrohydrolysis (see Fig.
1):
5.4 Vials—Polystyrene, 70-mL capacity, with liner-less
5.9.1 Silica Tube-Furnace and Accessories:
leakproof polyethylene screw cap.
5.9.1.1 Quartz Combustion Tube—Translucent, pure silica
5.5 Dispensing Bottles—Polyethylene,250-mLcapacity,for
(25-mm outside diameter, 20-mm inside diameter) of length
the standard fluorine solution (6.3.1) and of 600-mL capacity
appropriate to the particular furnace used. Preferably, the gas
for the absorption solution (6.3.3) and buffer (6.3.5).
outlet end should be narrowed to a tubulure of approximately
5.6 Micropipettes—Polypropylene or other suitable
7 mm in diameter.
polymer, variable volumes ranging from 0.1 mLto at least 2.0
NOTE 1—Combustion tubes of alternative refractory compositions do
mL.This is a satisfactory alternative to the 250-mLdispensing
nothaveadequatethermalstresscharacteristicsforoperationwiththistest
bottle (5.5), for the delivery of small volumes of the standard
method.
fluorine solution.
5.9.1.2 Silicone Stoppers—20mmindiameter,positionedat
5.7 Glass Dropper Bottle—30-mL capacity for dispensing inlet end and outlet, if applicable, of silica combustion tube
glacial acetic acid. (5.9.1.1).
FIG. 1 Pyrohydrolysis Furnace and Fluorine Absorption Assembly
D5987 − 96 (2007)
5.9.1.3 Combustion Boats—Unglazed porcelain, high alu- 6. Reagents
mina content, approximately 97 mm by 16 mm by 12 mm,
6.1 Purity of Reagents—Reagent grade chemicals shall be
preheated at 1000°C for 1 h.
used in all tests. Unless otherwise indicated, it is intended that
5.9.1.4 Silica Pusher and T-Tube—A silica push rod of
all chemicals shall conform to the specifications of the com-
dimensions 5 mm in diameter by 50 cm long, fused at one end
mittee on Analytical Reagents of the American Chemical
to provide a flat disk surface of 10 to 12 mm in diameter and
Society, where such specifications are available. Other grades
having a piece of magnetic steel affixed to the other end by
may be used, provided it is first ascertained that the reagent is
epoxy resin. The T-tube, 50 cm long, is composed of borosili-
of sufficiently high purity to permit its use without lessening
cate glass and protrudes 10 mm into the silica tube (5.9.1.1)
the accuracy of the determination.
through a stopper (5.9.1.2). A magnet is used to move the
6.2 Reagent Water—Reagent water conforming to type IV
pusher inside the T-tube.
of Specification D1193, shall be used in all cases unless
5.9.1.5 Combustion Furnace—Capable of reaching a maxi-
otherwise indicated. (Warning— Some reagents used in this
mum temperature of at least 1100°C.
test method are hazardous. Follow the precautions listed in the
5.9.1.6 Heating Tape and Power Regulator—To prevent
Material Safety Data Sheets of the manufacturer for each
condensationfromformingintheoutletendofthecombustion
reagent. )
train.
6.3 Solutions for ISE Test Method:
5.9.2 Steam Generator (Fig. 1):
5.9.2.1 Round Bottom Flask—Glass, 2-L capacity. 6.3.1 Standard Fluoride Solution (1 g=200 µg fluoride)—
The following standard fluoride solutions are required:
5.9.2.2 Heating Mantle—Ofsizesufficienttoheattheround
bottom flask (5.9.1.1). 6.3.1.1 For Direct Comparison Method—Dissolve 0.2210
6 0.0002 g of dry (110°C for 1 h) sodium fluoride in
5.9.2.3 Y-piece—Glass, 10 mm in diameter.
approximately 400 mL of water in a 500-mL polypropylene
5.9.2.4 Gas Distribution Tube—Zero porosity.
beaker. Transfer by thorough rinsing with water to a 500-mL
5.9.2.5 Stopcocks—One three-way and one two-way.
polypropylene volumetric flask. Dilute to mark with water and
5.9.2.6 Flowmeter—Capable of regulating and delivering at
mix. Discard after one month.
least 1000 mL/min of the oxygen.
5.9.3 Absorption Vessel Components: NOTE 3—There will not be a classic meniscus in polypropylene
volumetrics. The solution will correctly appear to have a flat surface.
5.9.3.1 Separatory Funnel—Glass, 125-mL capacity for
rinsing Graham Condenser into receiving flask, with stopcock
6.3.1.2 For Analyte-Addition Test Method—Dissolve0.2210
and 24/40 joint with drip tip.
60.0002gofdry(110°Cfor1h)sodiumfluorideina500-mL
5.9.3.2 Graham Condenser—For condensing polypropylenebeakercontaining150mLofwaterand250mL
hydropyrolysate, with 24/40 outer joint at top. Water jacket of an unspiked buffered absorption solution (see 6.3.3).
Transfer, by thorough rinsing with water, to a 500-mL poly-
length should be 300 mm.
propylene volumetric flask. Dilute with water to the mark and
5.9.3.3 Receiving Flask—250-mL capacity, flat bottom,
mix. Discard after one month (see Note 3).
wide neck, and tooled mouth, for collection of pyrohydroly-
sate. 6.3.2 Absorption Solution(0.025 MNaOH)—Dissolve2.0g
of sodium hydroxide in about 500 mL of water. Transfer to a
5.10 Ion-specific Electrode (ISE) Measurement Apparatus:
2.0-Lpolypropylene flask, dilute to mark with water, and mix.
5.10.1 Specific Ion Meter—ApH meter with an expandable
6.3.3 Unspiked Buffered Absorption (pH 6.5)—Dissolve
millivolt scale sensitive to 0.1 mV, specific-ion meter or
10.0gofpotassiumnitrate,2.0gofsodiumhydroxide,and115
equivalent, suitable for method of standard addition determi-
g of ammonium acetate in 1700 mLof water.Adjust pH to 6.5
nations.
with a small amount of glacial acetic acid. Transfer to a 2.0-L
5.10.2 Electrodes—Solid-state fluoride sensing, with the
polypropylene flask, dilute to mark with water, and mix.
appropriate reference-type electrode as recommended by the
6.3.4 Buffer Added After Tube-Furnace Hydrolysis (pH
manufacturer.
6.5)—Dissolve 10.0 g of potassium nitrate and 115 g of
NOTE 2—The fluoride sensing element should be polished frequently ammonium acetate in 350 mL of water.Adjust pH to 6.5 with
and in accordance with the manufacturer’s suggestions to prolong its
a small amount of glacial acetic acid. Transfer to a 500-mL
optimal performance.
polypropylene volumetric flask, dilute to mark with water, and
5.10.3 Magnetic Stirrer—Complete with polytetrafluoroeth- mix.
ylene (PTFE) stirring bars and magnet for convenient removal
6.3.5 Solution for Conditioning Fluoride ISE—Using a
of bars from vials.
pipette, transfer 20.0 mL of water, 20.0 mL of absorbing
5.11 Ion-Chromatograph (IC)—Equipped with three, 3 by
250-mmAS-3anionseparatorcolumnsandafibersuppressor.
Reagent Chemicals, American Chemical Society Specifications , American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Midgley, D., and Torrance, K., “Potentiometric Water Analysis,” John Wiley Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and Sons, 1978. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Rice, T. D., Analytica Chimica Acta, 1983, 151, pp. 383–389. MD.
D5987 − 96 (2007)
solution (6.3.2), and 10.0 mL of buffer (6.3.4) into a polysty- (5.9.2.1) containing 1600 mL of water. Allow the steam
rene vial (5.2). Add 200 µL of standard fluoride solution generator to achieve a gentle boil. Place an empty receiving
(6.3.1.1) and mix. flask (5.9.3.3) under the Graham condenser. With the furnace
set at an operational temperature of 1100°C, pass oxygen
6.4 Solutions for Ion-Chromatographic Measurement:
through the steam generator into the furnace at approximately
6.4.1 Standard Fluoride Solution (1000 µg/mL fluoride)—
1000 mL/min for 15 min.
Dissolve 2.2110 6 0.0002 g of dry (105°C for 1 h) sodium
8.2.2 Pyrohydrolysis:
fluorideina250-mLpolypropylenebeakercontainingapproxi-
8.2.2.1 Add 50 6 1 mL of the appropriate absorption
mately150mLofwater.Transferwiththoroughrinsesofwater
solution (6.3.2) for ISE finish or 65 6 1 mL of the absorption
toa1.0-Lpolypropylenevolumetricflask.Dilutewithwaterto
solution (6.4.5) for the IC finish to a clean receiving flask
the mark and mix (see Note 3).
(5.9.3). Place the flask underneath the condenser. Ensure that
6.4.2 Standard Fluoride Solution (1.0 µg/mL fluoride)—
cooling water is passing through the condenser.
Transfer, by means of polypropylene pipette, 1.0 mL of
8.2.2.2 Allow oxygen to flow, bypassing the steam
standard fluoride solution (6.4.1) to a 1.0-L polypropylene
generator, at 750 mL/min into the furnace. Place the analysis
volumetric flask; dilute to mark with water and mix (see Note
sampleboatintoazoneatwhichthetemperatureofthesample
3). Prepare fresh solution daily.
will not exceed 300°C. Redirect the oxygen flow through the
6.4.3 Sulfuric Acid, Standard (2.5 N)—Cautiously dilute 71
steam generator and into the furnace. At subsequent intervals
mL of sulfuric acid (H SO , sp gr 1.834 to 1.836) to 1 L with
2 4
of approximately 30 s, push the analysis sample boat into
water. Mix well.
hotterzoneswiththetemperaturenotexceeding400,500,750,
6.4.4 Sulfuric Acid, Standard (0.025 N)—For use as sup-
and 1000°C, with a final push into the hottest zone.
pressor regenerator. Using a pipette, cautiously dilute 10.0 mL
8.2.2.3 Continue the pyrohydrolysis for a further 15 min,
of 2.5 N H SO (6.4.3) to 1 L with water. Mix well.
2 4
while monitoring the flow of oxygen and the level of water in
6.4.5 Sodium Bicarbonate Solution (0.0015 M)—Weak
the round bottom flask.
eluent, for use as the absorbing solution and the Graham
8.2.3 Pyrohydrolysate Processing for ISE Finish:
condenser rinsing solution. Dissolve 0.2520 g of dry (105°C
8.2.3.1 At the completion of the pyrohydrolysis time, redi-
for 1 h) NaHCO in water and dilute to 2.0 L. Mix well.
rect the oxygen flow around the steam generator and allow
6.4.6 Sodium Bicarbonate Solution (0.02 M)—Strong elu-
excess steam to escape.
ent.Dissolve1.6801gofdry(105°Cfor1h)NaHCO inwater
and dilute to 1.0-L. Mix well.
NOTE 4—Caution should be exercised as to the direction in which the
steam is vented. Preferably it should be allowed to escape into a sink or
6.5 Oxygen—Free of combustible matter and guaranteed to
similar facility.
be 99.5% pure.
8.2.3.2 Rinsethecondenserwithtwo5-mLaliquotsofwater
6.6 Helium—Refer to ion chromatograph manu
...