ASTM E1645-01(2007)
(Practice)Standard Practice for Preparation of Dried Paint Samples by Hotplate or Microwave Digestion for Subsequent Lead Analysis
Standard Practice for Preparation of Dried Paint Samples by Hotplate or Microwave Digestion for Subsequent Lead Analysis
SIGNIFICANCE AND USE
Paint in buildings and related structures needs to be monitored for lead content in order to determine the potential lead hazard. Hence, effective and efficient methods are required for the preparation of paint samples that may contain lead.
This practice may be used for the digestion of paint samples that are collected during various lead-hazard control and risk assessment activities associated with lead abatement in and around buildings and related structures. This practice is also suitable for the digestion of paint samples collected from locations such as commercial buildings.
This practice may be used to prepare samples that have been obtained in order to ensure compliance with laws that govern lead content in paints.
This practice may be used to prepare samples that have been collected for risk assessment purposes.
This practice is intended for use with paint samples that are prepared for subsequent analysis by laboratory-based quantitative analytical methods.
SCOPE
1.1 This practice covers the sample preparation procedures for paint samples that are collected during the assessment, management or control of lead hazards.
1.2 This practice describes the digestion procedures using a hot plate or microwave oven or apparatus for paint samples that are to be analyzed for lead content.
1.3 This practice covers the general considerations for quantitative sample extraction for total recoverable lead in dried paint samples (either bulk paint or paint powder) using hot plate or microwave heating techniques, or both.
1.4 The values stated in SI units are to be regarded as the standard.
1.5 This practice contains notes that are explanatory and not part of the mandatory requirements of the standard.
1.6 This practice is based on two NIOSH Methods, 7082 and 7105, and on an EPA standard operating procedure for lead in paint.
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 specific precautionary statements, see 6.2.4.4 and 7.2.1.
General Information
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Standards Content (Sample)
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: E1645 − 01(Reapproved 2007)
Standard Practice for
Preparation of Dried Paint Samples by Hotplate or
Microwave Digestion for Subsequent Lead Analysis
This standard is issued under the fixed designation E1645; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope E1729 Practice for Field Collection of Dried Paint Samples
for Subsequent Lead Determination
1.1 This practice covers the sample preparation procedures
2.2 Other Documents:
for paint samples that are collected during the assessment,
Environmental ProtectionAgency, Standard Operating Pro-
management or control of lead hazards.
cedures for Lead in Paint by Hotplate- or Microwave-
1.2 This practice describes the digestion procedures using a
based Acid Digestions and Atomic Absorption or Induc-
hotplateormicrowaveovenorapparatusforpaintsamplesthat
tively Coupled Plasma Emission Spectrometry ; U.S. EPA,
are to be analyzed for lead content.
Research Triangle Park, NC (1991). (NTIS No.
1.3 This practice covers the general considerations for PB92–114172)
NIOSH Manual of Analytical Methods, P.M. Eller and M.E.
quantitative sample extraction for total recoverable lead in
dried paint samples (either bulk paint or paint powder) using Cassinelli, Eds., 4th ed., Methods 7082 and 7105; Na-
tional Institute for Occupational Safety & Health,
hot plate or microwave heating techniques, or both.
Cincinnati, OH (1994).
1.4 The values stated in SI units are to be regarded as the
standard.
3. Terminology
1.5 This practice contains notes that are explanatory and not
3.1 Definitions—For definitions of terms relating to the
part of the mandatory requirements of the standard.
preparation of dried paint samples that are not given here, refer
to Terminology D1129, or Terminology E1605.
1.6 This practice is based on two NIOSH Methods, 7082
3.1.1 batch—a group of field or quality control samples that
and7105,andonanEPAstandardoperatingprocedureforlead
are processed together using the same reagents and equipment.
in paint.
3.1.2 digestate—an acidified aqueous solution that results
1.7 This standard does not purport to address all of the
from digestion of the sample.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1.3 digestion—the sample preparation process that solubi-
priate safety and health practices and determine the applica-
lizes (extracts) targeted analytes present in the sample, and
bility of regulatory limitations prior to use. For specific
results in an acidified aqueous solution called the digestate.
precautionary statements, see 6.2.4.4 and 7.2.1.
3.1.4 extraction—the dissolution of target analytes from a
solid matrix into a liquid form. During sample digestion, target
2. Referenced Documents
analytes are extracted (solubilized) into an acid solution.
2.1 ASTM Standards:
3.1.5 method blank—a sample, devoid of analyte, that is
D1129 Terminology Relating to Water
analyzed to determine its contribution to the total blank
D1193 Specification for Reagent Water
(background) reading.
E1605 Terminology Relating to Lead in Buildings
3.1.6 non-spiked sample—a sample, devoid of analyte, that
is targeted for addition of analyte but is not fortified with all
target analytes prior to sample preparation.
This practice is under the jurisdiction of ASTM Committee E06 on Perfor-
3.1.6.1 Discussion—Analysis results for this sample are
manceofBuildingsandisthedirectresponsibilityofSubcommitteeE06.23onLead
used to correct for background levels in the blank medium that
Hazards Associated with Buildings.
Current edition approved Aug. 1, 2007. Published August 2007. Originally
is used for spiked and spiked duplicate samples.
approved in 1994. Last previous edition approved in 2001 as E1465 – 01 DOI:
10.1520/E1645-01R07.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from National Technical Information Service (NTIS), 5285 Port
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Royal Rd., Springfield, VA 22161, http://www.ntis.gov.
Standards volume information, refer to the standard’s Document Summary page on Available from NIOSH Publications, 4676 Columbia Parkway, Cincinnati, OH
the ASTM website. 45226; (800)35–NIOSH.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1645 − 01 (2007)
3.1.7 reagent blank—a digestate that reflects the maximum silicate glass container (on the hot plate) filled with digestion
treatment given any one sample within a batch of samples, solution, should be attainable. (See Note 1.)
except that it has no sample placed initially into the digestion
NOTE 1—Provided that the hot plate is capable of handling the extra
vessel. (The same reagents and processing conditions that are
heating required, use of a 12 to 25-mm (approximately 0.5 to 1-in.) thick
applied to field samples within a batch are also applied to the
aluminum plate placed on the burner head can help reduce the presence of
hot spots common to electric hot plates.
reagent blank.)
3.1.7.1 Discussion—Analysis results from this sample pro-
6.1.2 Microwave Extraction Apparatus
vide information on the level of potential contamination
Caution: Ensure that manufacturer’s safety recommenda-
resulting from only laboratory sources that are experienced by
tions are followed.
samples processed within the batch.
NOTE 2—The procedure described is for microwave digestion systems
3.1.8 reference material (certified reference material)
with a temperature control system. Microwave digestion systems that are
(CRM)—a material of known composition where the lead level
equipped only with a pressure control system or lower pressure vessels, or
is certified by the manufacturer. both, may be used, provided that a prior assessment of the dissolution
efficiency is carried out.
3.1.9 sample set—a group of samples (one or more).
6.1.2.1 Microwave Digestion System—designed for closed
3.1.10 spiked sample or spiked duplicate sample—a blank
vessel digestion, with power output regulation, fitted with a
medium that contains no purposely added analyte to which a
temperature control system capable of sensing the temperature
known amount of analyte is added before preparation.
to within 62°C, and automatically adjusting the microwave
3.1.10.1 Discussion—Analysis results for these samples are
power output within 2 s. The microwave cavity shall be
used to provide information on the precision and accuracy of
resistant to chemical attack, and equipped with exhaust venti-
the overall process.
lation for acid vapor protection of the unit and operator. All
electronics shall be protected against corrosion to ensure safe
4. Summary of Practice
operation. Safety interlocks, to shut off magnetron power
4.1 Lead in dried paint samples (chips, powder, etc.) is
output, shall be contained within the oven door opening
solubilized (extracted) by digestion with nitric acid and hydro-
mechanism.
gen peroxide facilitated by heat, or by a mixture of nitric acid
Caution: Domestic (kitchen) microwave ovens shall not be
and hydrochloric acid facilitated by microwave energy. (It is
used, since there are very significant hazards associated with
assumed that the paint samples were collected in accordance
their use for the procedure described in this standard. For
withPracticeE1729;however,thispracticecanbeusedforany
example, acid vapors released into the cavity can corrode
collected paint sample.) The lead content of the digested
safety devices that prevent the magnetron from shutting off
sample is then in a form ready for measurement.
when the door is opened, potentially exposing the operator to
microwaveenergy.Also,thefumesgeneratedcanbeextremely
5. Significance and Use
hazardous.
5.1 Paint in buildings and related structures needs to be
NOTE3—Apressurecontrolsystemisalsoveryuseful,sinceitprovides
monitored for lead content in order to determine the potential
asafeguardagainstthepossibilityofsamplelossduetoexcessivepressure
leadhazard.Hence,effectiveandefficientmethodsarerequired
buildup and partial venting of the sample vessels.
for the preparation of paint samples that may contain lead.
6.1.2.2 Lined Sample Vessels—closed, designed for carrying
5.2 This practice may be used for the digestion of paint
out microwave digestions, capable of withstanding a tempera-
samples that are collected during various lead-hazard control
tureofatleast180°Candwithaninternalvolumeofatleast50
andriskassessmentactivitiesassociatedwithleadabatementin
mL.The vessels must be transparent to microwave energy, and
and around buildings and related structures. This practice is
vessel liners shall be chemically inert. The vessels must be
also suitable for the digestion of paint samples collected from
capable of withstanding high internal pressures (up to at least
locations such as commercial buildings.
3000 kPa) and temperatures (up to at least 180°C). Vessels
shallalsobeequippedwithasafetyreliefvalveordiscthatwill
5.3 This practice may be used to prepare samples that have
prevent vessel rupture or ejection of the vessel cap. Such
been obtained in order to ensure compliance with laws that
vessels consist of an inner liner and cover made of a micro-
govern lead content in paints.
wave transparent and chemically resistant material (usually a
5.4 This practice may be used to prepare samples that have
fluorocarbon polymer such as tetra-fluoromethoxil polymer
been collected for risk assessment purposes.
(TFM), which contains and isolates the sample solution from a
5.5 This practice is intended for use with paint samples that
high strength, outer pressure structure. Other types of sample
are prepared for subsequent analysis by laboratory-based
vessels designed to operate at equivalent or higher tempera-
quantitative analytical methods.
tures or pressures, or both, may be used.
Caution: For closed vessel designs, the material from which
6. Apparatus
the outer vessels are made is usually not as chemically inert as
6.1 Heating Equipment: the liner material. Since the outer vessels provide the strength
6.1.1 Electric Hot Plate—suitable for operation at surface required to withstand the high pressures within the inner liners,
temperatures up to at least 140°C. A temperature of at least they must be inspected regularly to check for any chemical or
100°C, as measured by a thermometer placed inside a boro- physical degradation.
E1645 − 01 (2007)
6.2 Reagents, Glassware and Supplies: 7.1.2.2 Remove any large amounts of substrate present in
6.2.1 Apparatus-Hot Plate Digestion: the sample. Exercise care when removing substrate to avoid
any losses of paint. If required, use a clean safety razor blade
6.2.1.1 Borosilicate glass beakers, 125-mL or 50-mL with
or equivalent tool to aid in substrate removal.
watchglass covers,
7.1.2.3 Determination of Total Collected Sample Mass—
6.2.1.2 Class A borosilicate volumetric flasks, 100–mL and
Accurate determination of the collected sample mass is re-
200–mL,
quired to report lead analysis results in terms of area concen-
6.2.1.3 Class A borosilicate volumetric pipets, volume as
tration (mass per unit area of paint sample). A complete
needed,
transfer of the sample is required to whatever preweighed
6.2.1.4 Linear polyethylene bottles with caps, 100–mL,
container is used to hold the sample during mass determination
6.2.1.5 Analytical balance, accurate to 60.1 mg,
(for example, weighing boat or weighing paper). Total mass
6.2.1.6 Glass funnels, and
shall be made to the nearest 0.1 mg.
6.2.1.7 Filter paper,
The following precautions shall be observed during deter-
6.2.1.8 Weighing Paper or Weighing Boat.
mination of total mass:
6.2.2 Apparatus-Microwave Digestion:
(1) Total sample mass can be determined either before or
6.2.2.1 Centrifuge, with 30 mLpolysulfone centrifuge tubes
after sample homogenization. Determination of total sample
and polypropylene screw closure,
mass is generally advisable prior to homogenization when
6.2.2.2 Class A volumetric and graduated pipets,
samples consist of large intact chips that can be easily
6.2.2.3 Mechanical shaker, and
transferred without incurring losses. Determination of total
6.2.2.4 Analytical balance, accurate to 60.1 mg.
sample mass is generally advisable after homogenization when
6.2.3 Reagents-Hot Plate Digestion:
samples can be homogenized in the original sample collection
6.2.3.1 Concentrated nitric acid, ACS reagent grade or
container and the samples are not large intact chips.
spectrographic grade 16.0 M HNO ,
NOTE 4—In this case, the sample container should be weighed after
6.2.3.2 Nitric acid, 10 % (w/v): Add 100 mL concentrated
homogenization.
HNO to 500 mL ASTM Type I water (see Specification
(2)Anyvisibletracesofpaintleftintheoriginalcontaineror
D1193). Dilute to 1 L with ASTM Type I water,
container used for homogenization (if different from original
6.2.3.3 Hydrogen peroxide, 30 % H O (w/w);ACS reagent
2 2
container) may result in bias of the final lead analysis results.
grade, and
Therefore,suchtracesshallbeminimized.Anyvisiblematerial
6.2.3.4 ASTM Type I water (see Specification D1193).
that cannot be transferred shall be documented in sample
6.2.4 Reagents-Microwave Digestion:
preparation records.
6.2.4.1 Concentrated nitric acid, ACS reagent grade or
(3) For sample transfers following homogenization, most
spectrographic grade 16.0 M HNO ,
losses caused by the presence of fine powder remaining in the
6.2.4.2 Concentrated hydrochloric acid, ACS reagent grade
original container or container used for homogenization (if
12.3 M HCl,
different from original container) will not result in any signifi-
6.2.4.3 ASTM Type I water (see Specification D1193), and
cant bias (particularly with respect to the large sampling
6.2.4.4 ExtractionSolution—Ina1-Lvolumetricflask,com-
variability that normally accompanies the field collection
bine the following in order and mix well: 500 mLASTM Type
practice.)
I water, 60 mL concentrated HNO and 180 mL concentrated
(4) For sample transfers prior to homogenization (that is,
HCl. Cool to room temperature and dilute to 1 L with ASTM
when homogenization cannot be performed in the original
Type I water. Caution: Nitric and hydrochloric acid fumes are
container used in sample collection), any losses caused by fine
toxic. Prepare in a well-ventilated fume hood.
powder remaining in the original container may result in a
significant bias. Therefore, sample transfers co
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