ASTM D5513-99
(Practice)Standard Practice for Microwave Digestion of Industrial Furnace Feedstreams and Waste for Trace Element Analysis
Standard Practice for Microwave Digestion of Industrial Furnace Feedstreams and Waste for Trace Element Analysis
SCOPE
1.1 This practice describes the multi-stage microwave digestion of typical industrial furnace feedstream materials using nitric, hydrofluoric, hydrochloric, and boric acids for the subsequent determination of trace metals.
1.2 This practice has been used successfully on samples of coal, coke, cement raw feed materials, and waste-derived fuels composed primarily of waste paint-related material in preparation for measuring the following trace elements: Ag, As, Ba, Be, Cd, Cr, Hg, Pb, Sb, and Tl. This practice may be applicable to elements not previously listed.
1.3 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. Specific hazard statements are given in Section 7.
General Information
Relations
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.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: D 5513 – 99
Standard Practice for
Microwave Digestion of Industrial Furnace Feedstreams and
Waste for Trace Element Analysis
This standard is issued under the fixed designation D 5513; 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 cycle, the vessel is vented and specified quantities of hydrof-
luoric and hydrochloric acids are added, and the mixture
1.1 This practice describes the multi-stage microwave di-
undergoes further microwave heating. Following this heating
gestion of typical industrial furnace feedstream materials using
cycle, the vessel is vented and a specified quantity of boric acid
nitric, hydrofluoric, hydrochloric, and boric acids for the
solution is added, and the mixture undergoes a final microwave
subsequent determination of trace metals.
heating. Following this final heating cycle, the vessel is vented,
1.2 This practice has been used successfully on samples of
the contents are quantitatively transferred to a volumetric flask
coal, coke, cement raw feed materials, and waste-derived fuels
and brought to volume. Typically, the only undissolved mate-
composed primarily of waste paint-related material in prepa-
rial is particulate carbon. If particulate matter is observed,
ration for measuring the following trace elements: Ag, As, Ba,
filtration or centrifugation may be needed. The digested sample
Be, Cd, Cr, Hg, Pb, Sb, and Tl. This practice may be applicable
is ready for analysis.
to elements not previously listed.
1.3 This practice is also effective for other waste materials
4. Significance and Use
(for example, flyash, foundry sand, alum process residue,
4.1 The U.S. Environmental Protection Agency Regula-
cement kiln dust, etc.).
tions, 40 CFR, require that boilers, cement kilns, and other
1.4 This standard does not purport to address all of the
industrial furnaces utilizing waste-derived fuel adhere to spe-
safety concerns, if any, associated with its use. It is the
cific guidelines in assessing potential metals emissions. A
responsibility of the user of this standard to establish appro-
common approach for estimating potential emissions is per-
priate safety and health practices and determine the applica-
forming total metals analysis on all feedstream materials. This
bility of regulatory limitations prior to use. Specific hazard
practice describes a multi-stage microwave-assisted digestion
statements are given in Section 7.
procedure that solubilizes trace elements for spectroscopic
2. Referenced Documents analyses.
2.1 ASTM Standards:
5. Apparatus
D 1193 Specifications for Reagent Water
5.1 Microwave Digestion Unit—Equipped with an auto-
2.2 Other Document:
matic turntable, pressure and/or temperature controller, and
40 CFR 266, Subpart H, Hazardous Waste Burned in
3 closed perfluoroalkoxy (PFA)-lined digestion vessels equipped
Boilers and Industrial Furnaces, Latest Revision
with pressure relief/rupture membrane fittings or equivalent
3. Summary of Practice pressure relief device. The unit should comply with applicable
federal or state standards, or both, for microwave leakage. The
3.1 A weighed portion of the feedstream material is com-
user must follow specific manufacturer’s instructions for sys-
bined with concentrated nitric acid in a
tem installation.
polytetrafluoroethylene-lined digestion vessel, and heated in a
microwave digestion unit. Following a programmed heating
NOTE 1—The digestion unit used in developing this practice was
equipped with a pressure controller, automatic turntable, exhaust fan, and
programming capacity. The unit delivers 1000 W of power at 100 %
This practice is under the jurisdiction of ASTM Committee D34 on Waste
output. The lined digestion vessels consist of a high-strength polymeric
Management and is the direct responsibility of Subcommittee D34.01.06 on
vessel body and cap, inner PFA liner and rupture membrane housing, and
Analytical Methods.
PFA vent stem. These vessels have a maximum operating pressure of 200
Current edition approved March 10, 1999. Published May 1999. Originally
psig. There are a number of suitable lab grade microwave systems
published as D 5513 – 94. Last previous edition D 5513 – 94 (1998).
available to the user that meet these minimum specifications. The user
Annual Book of ASTM Standards, Vol 11.01.
3 must follow specific manufacturer’s instructions for using digestion
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
vessels.
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, 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.
D5513–99
5.2 Analytical Balance—Capable of weighing to 0.001 g. 8. Sample
5.3 Labware—High-density volumetric polyethylene or
8.1 Although feedstream materials are generally pulverized
polypropylene flasks/sample containers are recommended for
powders or liquids, the homogeneity of some feedstream
this practice. The user should be mindful of the quality
materials can be uncertain. The laboratory sample should be
limitations associated with volumetric non-glass labware.
thoroughly mixed or homogenized prior to withdrawing a
portion for analysis. This practice assumes that non-liquid
6. Reagents and Materials
feedstreams are pulverized powders at the time of sample
6.1 Purity of Reagents—Reagent grade chemicals shall be
preparation.
used in all tests. Unless otherwise indicated, it is intended that
NOTE 2—If a non-liquid feedstream material is not in the form of a
all reagents conform to the specifications of the Committee on
pulverized powder, it may need to be reduced in particle size to pass
Analytical Reagents of the American Chemical Society where
4 through a No. 100 sieve.
such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
9. Calibration and Standardization
high purity to permit its use without lessening the accuracy of
9.1 Although equipment manufacturers specify general
the determination.
power output ratings for microwave digestion units, it is
6.2 Purity of Water—Unless otherwise indicated, references
important to verify the actual power output of a specific unit. It
to water shall be understood to mean meeting the numerical
is recommended that this microwave power check procedure
requirements of Type II water as defined by Specifications
be performed monthly.
D 1193.
9.1.1 Power Check Procedure at 100 % Instrument Power:
6.3 Boric Acid Solution (20 g/L)—Dissolve 20 g of boric
9.1.1.1 Remove from the instrument cavity the turntable,
acid (H BO ) in water and dilute to 1 L. It may be necessary
3 3
to place solution on a combination hot plate/magnetic stirrer drive lug, and all vessels.
and with the aid of a stir bar, allow the solution to mix under 9.1.1.2 Adjust the instrument cavity exhaust to minimum air
gentle heat until boric acid is fully in solution.
flow (refer to the manufacturer’s instructions).
6.4 Hydrochloric Acid, 37 %, (sp. gr. 1.200), HCl.
9.1.1.3 Program the instrument for 4-min time and 100 %
6.5 Hydrofluoric Acid, 48 %, (sp. gr. 1.150), HF.
power.
6.6 Nitric Acid, 70 %, (sp. gr. 1.400), HNO .
3 9.1.1.4 Transfer 2000 6 2 mL of room temperature (19 to
25°C) water into a 2-L polypropylene beaker.
7. Hazards
9.1.1.5 Measure and record the initial water temperature (T )
i
7.1 It is recommended that all operations involving concen-
to the nearest 0.1°C.
trated acids be performed in a laboratory fume hood.
9.1.1.6 Place the beaker in the right front corner of the
7.2 Hydrochloric acid is a highly corrosive chemical that is
instrument cavity (as you face the front of the instrument). This
reactive with metals and most alkaline chemicals. Impervious
position closely approximates the position of a digestion vessel
gloves and chemical goggles are required for handling. See
during processing.
material safety data sheet (MSDS) for additional information.
9.1.1.7 Heat the water for the programmed time.
7.3 Hydrofluoric acid is a highly corrosive chemical that is
9.1.1.8 When the heating cycle is complete, immediately
reactive with metals and water or steam. Additionally, HF
remove the beaker from the cavity, thoroughly stir the water to
specifically attacks silicate glass making certain fume hood
ensure even heat distribution, and measure the final tempera-
enclosures susceptible to damage. Impervious gloves and
ture (T ) to the nearest 0.1°C.
f
chemical goggles are required for handling. See MSDS for
9.1.1.9 Calculate the delivered power in accordance with
additional information.
the following equations:
7.4 Nitric acid is a highly corrosive chemical that is reactive
Power ~watts!5DT 3 ~35 W/°C! (1)
with metals and most organic materials. Impervious gloves and
chemical goggles are required for handling. See MSDS for
where:
additional information.
DT = T − T .
f i
7.5 Some samples undergoing microwave digestion can
W/°C = K 3 Cp 3 M
exhibit a rapid pressure rise within the digestion vessel. The
t
potential exists for this type of sample to rupture the rupture
membrane and liberate corrosive gases. Because of this, the
microwave unit must be vented to a fume hood for proper
where:
evacuation of vapors.
W = watts,
K = 4.2, the factor for converting thermo-chemical
calories/s to joules to watts.
Reagent Chemicals, American Chemical Society Specifications, American
−1 −1
Cp = 1.0, the heat capacity for water, cal g degree ,
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
M = mass of water, g (1 mL H O = 1 g), and
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
t = time, s.
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
9.1.1.10 If the calculated power is not within the specifica-
MD.
tions of the unit, do a second test beginning at 9.1.1.1 for
This information taken from the NIOSH Guide to Chemical Hazards, U.S.
Depart. of Health and Human Services, June 1990. confirmation before contacting the manufacturer.
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.
D5513–99
10. Procedure 10.1.9.1 Flush the pressure sensing tubing with water to
remove any trace of acid. This is an important step, because
NOTE 3—Many microwave digestion units are capable of handling up
damage will occ
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.