ASTM E926-94

Standard Practices for Preparing Refuse-Derived Fuel (RDF) Samples for Analyses of Metals (Withdrawn 2002)

SCOPE
1.1 These practices described herein cover the preparation of milled refuse-derived fuel (RDF) sample for analyses of metals by atomic absorption spectroscopy or inductively coupled plasma spectroscopy (see Appendix X1), or both.  
1.2 These practices may be applicable to any waste material from which a laboratory analysis sample can be prepared.  
1.3 The following four practices are described in this standard:  
1.3.1 Practice A -Nitric-Hydrofluoric-Perchloric Acid Digestion.  
1.3.2 Practice B -Nitric-Sulfuric-Hydrofluoric Acid Digestion.  
1.3.3 Practice C -Bomb, Acid Digestion Method.  
1.3.4 Practice D -Oxygen Bomb Combustion Method.  
1.4 The four practices will cover the scope of preparing most RDF samples for subsequent analyses of most metals. Many times the nature of the sample and the metal in question will dictate the sample preparation technique. In such cases, modifications of these practices may be made with care as to not alter the integrity of the analyte in question.  
1.5 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 hazard statements, see Sections 9, 10.6, 14, 19, and 24.

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-1993
• ICS: 75.160.10 - Solid fuels
• Technical Committee: D34 - Waste Management
• Drafting Committee: D34.03 - Treatment, Recovery and Reuse

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 926 – 94
Standard Practices for
Preparing Refuse-Derived Fuel (RDF) Samples for Analyses
of Metals
This standard is issued under the fixed designation E 926; 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 Laboratory Samples for Analysis
1.1 These practices described herein cover the preparation
3. Summary of Practice
of milled refuse-derived fuel (RDF) sample for analyses of
3.1 The organic matter of the analysis sample is completely
metals by atomic absorption spectroscopy or inductively
destroyed by strong acid digestion and oxidation. The inor-
coupled plasma spectroscopy (see Appendix X1), or both.
ganic constituents are solubilized and the resulting solution
1.2 These practices may be applicable to any waste material
analyzed for metals by either atomic absorption spectroscopy
from which a laboratory analysis sample can be prepared.
or inductively coupled plasma spectroscopy.
1.3 The following four practices are described in this
standard:
4. Significance and Use
1.3.1 Practice A—Nitric-Hydrofluoric-Perchloric Acid Di-
4.1 These practices are available to producers and users of
gestion.
RDF for preparing RDF samples for subsequent analyses of
1.3.2 Practice B—Nitric-Sulfuric-Hydrofluoric Acid Diges-
metals.
tion.
1.3.3 Practice C—Bomb, Acid Digestion Method.
5. Apparatus
1.3.4 Practice D—Oxygen Bomb Combustion Method.
5.1 Analytical Balance, capable of weighing to 0.0001 g.
1.4 The four practices will cover the scope of preparing
5.2 TFE-fluorocarbon Beakers, 500-mL capacity.
most RDF samples for subsequent analyses of most metals.
5.3 Hot Plate, capable of heating to at least 510°C.
Many times the nature of the sample and the metal in question
5.4 Volumetric Flasks, 50, 100, and 250-mL.
will dictate the sample preparation technique. In such cases,
modifications of these practices may be made with care as to
6. Reagents and Materials
not alter the integrity of the analyte in question.
6.1 Purity of Reagents—Reagent grade chemicals shall be
1.5 This standard does not purport to address all of the
used in this test. Unless otherwise indicated, it is intended that
safety concerns, if any, associated with its use. It is the
all reagents shall conform to the specifications of the Commit-
responsibility of the user of this standard to establish appro-
tee on Analytical Reagents of the American Chemical Society
priate safety and health practices and determine the applica-
where such specifications are available. Other grades may be
bility of regulatory limitations prior to use. For hazard state-
used, provided it is first ascertained that the reagent is of
ments, see Sections 9, 10.6, 14, 19, and 24.
sufficiently high purity to permit its use without lessening the
accuracy of the determination.
2. Referenced Documents
6.2 Purity of Water—Unless otherwise indicated, reference
2.1 ASTM Standards:
to water shall be understood to mean at least Type III reagent
D 1193 Specification for Reagent Water
water conforming to Specification D 1193.
E 711 Test Method for Gross Calorific Value of Refuse-
6.3 Nitric Acid (HNO ), concentrated sp gr 1.42.
Derived Fuel by the Bomb Calorimeter
6.4 Hydrofluoric Acid (HF), 48 %.
E 829 Practice for Preparing Refuse-Derived Fuel (RDF)
1 4
These practices are under the jurisdiction of ASTM Committee D34 on Waste tTradename for tetrafluoroethylene (TFE) fluorocarbon polymer.
Management and is the direct responsibility of Subcommittee D34.06 on Recovery Reagent Chemicals, American Chemical Society Specifications, American
and Reuse. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Current edition approved Aug. 15, 1994. Published October 1994. Originally listed by the American Chemical Society, see Analar Standards for Laboratory
published as E 926 – 83. Last previous edition E 926 – 88. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Annual Book of ASTM Standards, Vol 11.01. and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 11.04. MD.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 926
6.5 Perchloric Acid (HClO ), concentrated 70 to 72 %. walls of the beaker with deionized water to ensure that all
6.6 Hydrochloric Acid (HCl), concentrated sp gr 1.19. material is in contact and can react with the acid mixtures.
10.5 Continue digesting until the solution becomes clear.
7. Hazards
Add additional HNO as needed.
7.1 Due to the origins of RDF in municipal waste, common
NOTE 2—Some samples will require several days for complete diges-
sense dictates that precautions should be observed when
tion to occur.
conducting tests on samples. Recommended hygienic practices
10.6 In a perchlorate hood add 10 mL of HClO to the
include use of gloves when handling RDF; wearing dust masks
digestion mixture, cover, and continue digestion on low heat
(NIOSH-approved type), especially while milling RDF
for several hours. At frequent intervals rinse the inside walls of
samples; conducting tests under a negative pressure hood when
the beaker with HF. Approximately 20 to 25 mL of additional
possible; and washing hands before eating or smoking.
HF can be added during this digestion (see Appendix X2).
7.2 The hot acidic solutions in these procedures pose a
significant potential hazard. Proper laboratory safety practices
NOTE 3—Warning: An excessively high temperature may cause an
and equipment should be employed throughout these proce- explosion if carbonaceous material is present. The addition of a cold
solution to hot acid solutions may cause splattering.
dures.
7.3 All wet ashing must be performed in a fume hood.
10.7 Remove the cover, elevate the hot plate temperature,
Where perchloric acid is used a perchlorate hood must be used.
and slowly evaporate to dryness.
10.8 Cool the contents and beaker to room temperature.
8. Sampling
10.9 Dissolve the solids in 35 to 50 mL of 10 % V/V
8.1 RDF products are frequently non-homogeneous. For
solution of HCl using moderate heat. If all material is not
this reason significant care should be exercised to obtain a
soluble, add 20 to 25 mL of HF and digest on low heat for an
representative laboratory sample from the RDF lot to be
additional hour. Continue as described in 10.7, 10.8, and 10.9.
characterized.
10.10 Quantitatively transfer the sample solution to a
8.2 The sampling method for these procedures should be
100-mL volumetric flask and dilute to mark with 1 % HCl
based upon agreement between involved parties.
solution.
8.3 The laboratory sample is prepared in accordance with
10.11 This solution will contain those metals as contained in
Practice E 829.
5 g of sample RDF in 100 mL of solution. Should a more
concentrated or a more dilute solution be required, the sample
PRACTICE A—NITRIC-HYDROFLUORIC-
size or the final dilution, or both, can be adjusted accordingly.
PERCHLORIC ACID DIGESTION
This adjustment will be a function of the magnitude of
9. Hazards
concentration of the metal in question and the sensitivity of the
method of analysis.
9.1 Hot acidic solutions in this procedure pose a significant
10.12 Prepare a reagent blank in the same manner as
potential hazard. Proper laboratory safety practices and equip-
described in 10.2-10.10 using the same volumes of acids used
ment should be employed throughout.
for the digestion of the sample.
9.2 All wet ashing must be performed in a perchlorate fume
hood.
PRACTICE B—NITRIC-SULFURIC-HYDROFLUORIC
9.3 Perchloric acid is a colorless, hygroscopic, strong oxi-
ACID DIGESTION
dizing agent. It can explode in contact with organic materials,
11. Summary of Practice
or by shock or heat. Controlled redox potential of perchloric
11.1 The organic matter of the analysis sample is com-
acid is imperative when used for oxidation of organic material
pletely destroyed by strong acid digestion and oxidation. The
(see Appendix X2).
inorganic constituents are solubilized and the resulting solution
10. Procedure
analyzed for metals by either atomic absorption spectroscopy
10.1 Weigh accurately approximately5gofthe analysis or inductively coupled plasma spectroscopy.
RDF sample into a 500-mL TFE-fluorocarbon beaker.
12. Apparatus
10.2 Add 50 mL of concentrated HNO . Cover the beaker
12.1 Analytical Balance, capable of weighing to 0.0001 g.
with a loose fitting cover.
12.2 Berzelius Beakers, 600-mL capacity.
10.3 Heat on low heat for several hours. Add HNO as
12.3 Hot Plate, capable of heating to at least 510°C.
needed. Continue heating until most of the organic matter is
12.4 Volumetric Flasks, 50, 100, and 250-mL.
decomposed.
13. Reagents and Materials
NOTE 1—Additions of HNO may be made to hot solutions without fear
13.1 Purity of Reagents—See 6.1.
of violent splattering if the acid is added by dropwise additions, or as a
13.2 Purity of Water—See 6.2.
thin stream from a wash bottle down the sides of the beaker.
13.3 Nitric Acid (NHO ), concentrated sp gr 1.42.
10.4 Slowly add 10 mL of 48 % HF, cover, and continue
13.4 Sulfuric Acid (H SO ), concentrated sp gr 1.84.
2 4
digesting the sample over low heat. Frequently rinse the inside
13.5 Hydrofluoric Acid (HF), 48 %.
14. Hazards
ASTM Subcommittee E38.01 is currently in the process of developing
procedures for sampling RDF. 14.1 Hot acidic solutions in this procedure pose a significant
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 926
of this final volume nearly impossible. In such instances, evaporate the
potential hazard. Proper laboratory safety practices and equip-
H SO to the lowest liquid volume discernible, then cease fuming when
ment should be employed throughout. 4
salts form a wet sludge.
14.2 All wet ashing must be performed in a fume hood.
15.12 Remove from heat and cool to room temperature.
15. Procedure
15.13 Transfer the solution quantitatively to a 100-mL
15.1 Weigh a suitable amount of RDF analysis sample and
volumetric flask, and dilute to mark with water.
place into a 600-mL Berzelius beaker. 15.14 This solution will contain those metals as contained in
the given amount of sample of RDF used in 100 mL of
NOTE 4—Should very low or high concentrations of the element in
solution. Should a more concentrated or a more dilute solution
question be anticipated, the amount of sample used and the dilution of the
be required, the sample size or the final dilution, or both, can
final solution can be adjusted accordingly.
NOTE 5—Recommended acid additions are given in Table 1. be adjusted accordingly. This adjustment will be a function of
the magnitude of concentration of the metal in question and the
15.2 Add a suitable volume of concentrated HNO and
sensitivity of the method of analysis.
cautiously digest over low to medium heat (see Note 6).
15.15 Prepare a reagent blank in the same manner as
NOTE 6—Warning: On prolonged digestion with nitric acid, some
described in 15.2-15.13, using the same volumes of acids used
materials from highly reactive compounds that erupt violently, result in
for the digestion of the sample.
critical loss of sample and possible danger to the operator.
15.3 When the initial vigorous reaction ceases, gradually PRACTICE C—BOMB, ACID DIGESTION METHOD
increase the temperature and evaporate to a 10 to 15-mL
16. Summary of Practice
volume.
15.4 Cool slightly and add H SO slowly in small incre- The organic matter of the analysis sample is completely
2 4
ments (5 to 10 mL). destroyed by strong acid digestion and oxidation in a closed
15.5 Return the beaker to high heat and evaporate to dense acid digestion bomb at low temperature. The inorganic con-
white fumes of sulfur trioxide (SO ). stituents are solubilized and the resulting solution analyzed for
15.6 Allow to fume until the solution in the beaker darkens, metals by either atomic absorption spectroscopy or inductively
then fume for 10 min more. coupled plasma spectroscopy.
15.7 Remove from the heat, cool until SO fumes are no
17. Apparatus
longer observed, then add HNO slowly and cautiously down
the inside of the beaker. 17.1 Analytical Balance, capable of weighing to 0.0001 g.
17.2 Bomb, Acid Digestion, TFE-fluorocarbon-lined, 25-mL
NOTE 7—Additions of HNO may be made to hot (not fuming) H SO
3 2 4
capacity, designed for high pressure decompositions.
without fear of violent splattering if the acid is added by dropwise
17.3 Oven, circulating air capable of maintaining a tempera-
additions, or as a thin stream from a wash bottle down the sides of the
ture of 110 6 0.5°C.
beaker.
17.4 Volumetric Flasks, 50, 100, and 250-mL.
15.8 Repeat 15.5, 15.6, and 15.7 until no further darkening
of the solution is noted on subsequent fumings.
18. Reagents and Materials
15.9 If the solution contains gelatinious silica (SiO ) pre-
18.1 Purity of Reagents—See 6.1.
cipitate, transfer the solution quantitatively to a 250-mL
18.2 Purity of Water—See 6.2.
TFE-fluorocarbon beaker with a minimum amount of water.
18.3 Nitric Acid (HNO ), concentrated sp gr 1.42.
15.10 Add 5 mL of HF and evaporate to fumes of SO .
NOTE 8—When any additions of HF or HCl are to be made to an H SO 19. Hazards
2 4
solution, the H SO solution must first be diluted with water and be near
2 4
19.1 Acid digestion bombs must be used according to the
room temperature. If highly accurate metals analysis (particularly Si, Al,
manufacturers’ specifications. That is, the limits on the
and Fe) is not required, the HF may be added directly to the sample in the
amounts of material that can be safely digested, the volume of
glass beaker.
acid added, and the temperatures of digestion cannot be
15.11 Allow the solution to cool to room temperature, add 5
exceeded.
mL of water and 5 mL of HCl, and again fume until a volume
of approximately 2 mL is reached.
20. Procedure
NOTE 9—Samples with appreciable salt content will render judgement 20.1 Weigh accurately about 0.1 g of RDF analysis sample
into the TFE-fluorocarbon cup of the acid digestion bomb.
TABLE 1 Recommended Acid Additions
20.2 Add no less than 2.5 nor more than 3.0 mL of
Initial Additions Subse-
concentrated HNO to the sample in the TFE-fluorocarbon cup.
Second Third
quent
20.3 Without de
...