ASTM D8404-21

Standard Practice for Preparation of Soil Samples by Ammonium Bifluoride-Nitric Acid Digestion for Subsequent Analysis for Metals and Metalloids

SIGNIFICANCE AND USE
5.1 There is a need to monitor the content of metals and metalloids in order to determine the presence of potential hazards. Hence, effective and efficient methods are required for the preparation of soil samples for determination of metals and metalloids present therein.  
5.2 This practice may be used for the digestion of soil samples that are collected during various construction and renovation and hazard survey activities in and around buildings and related structures. The practice is also suitable for the digestion of soil samples for metal and metalloid analyses collected from other locations, such as near roads and steel structures. For some other extraction procedures, see Practices D3974.  
5.3 This practice is intended to be used to prepare samples that have been collected for hazard assessment purposes but may be used for other applications such as, for example, monitoring the effectiveness of remediation activities.  
5.4 This practice may be capable of determining metals and metalloids bound within matrices, such as silica, that are not soluble in nitric acid alone.  
5.5 This practice includes drying and homogenization steps to help assure that reported results are representative of the sample and are independent of potential differences in soil moisture levels among different sampling locations or changing weather conditions.
SCOPE
1.1 This practice covers drying, homogenization, and ammonium bifluoride-nitric acid digestion of soil samples and associated quality control (QC) samples for the determination of metals and metalloids using laboratory atomic spectrometry analysis techniques such as inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES), flame atomic absorption spectrometry (FAAS), and graphite furnace atomic absorption spectrometry (GFAAS). For ammonium bifluoride-nitric acid digestion of airborne dust and dust-wipe samples for the determination of metals and metalloids, see Practice D8344.  
1.2 This practice is based on U.S. EPA SW 846, Test Method 3050, Test Method D7202, and Practice D8344.  
1.3 This practice contains notes that are explanatory and are not part of the mandatory requirements of this standard.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2021
• ICS: 13.040.30 - Workplace atmospheres
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.04 - Workplace Air Quality

Relations

• Refers: ASTM E1727-24 - Standard Practice for Field Collection of Soil Samples for Subsequent Lead Determination
• Effective Date: 01-Mar-2024
• Refers: ASTM D3974-09(2023) - Standard Practices for Extraction of Trace Elements from Sediments
• Effective Date: 15-Dec-2023
• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM E1605-18b - Standard Terminology Relating to Lead in Buildings
• Effective Date: 15-Dec-2018
• Refers: ASTM E1605-18a - Standard Terminology Relating to Lead in Buildings
• Effective Date: 01-Oct-2018
• Refers: ASTM E1605-18 - Standard Terminology Relating to Lead in Buildings
• Effective Date: 01-Sep-2018
• Refers: ASTM D4840-99(2018)e1 - Standard Guide for Sample Chain-of-Custody Procedures
• Effective Date: 15-Aug-2018
• Refers: ASTM E288-10(2017) - Standard Specification for Laboratory Glass Volumetric Flasks
• Effective Date: 01-Nov-2017
• Refers: ASTM E882-10(2016)e1 - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM E882-10(2016) - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM D3974-09(2015) - Standard Practices for Extraction of Trace Elements from Sediments
• Effective Date: 01-Jan-2015

Overview

ASTM D8404-21 provides a standardized practice for the preparation of soil samples using ammonium bifluoride-nitric acid digestion, specifically designed for the subsequent analysis of metals and metalloids. Developed by ASTM International, this standard is critical for laboratories and professionals involved in environmental monitoring, hazard assessment, and quality control regarding soil contamination. Its procedures ensure efficient and effective extraction of metals and metalloids from soil matrices, including those bound within silica and other non-nitric acid soluble materials.

Meeting international compliance expectations, ASTM D8404-21 aligns with recognized principles for the development of international standards, supporting consistent and reliable laboratory performance worldwide.

Key Topics

• Sample Preparation: Involves drying, homogenizing, and sieving soil samples to ensure representativeness and reduce variability caused by moisture or particle size differences.
• Digestion Process: Utilizes a combination of ammonium bifluoride and nitric acid to break down soil matrices, enabling the release and detection of metals and metalloids.
• Analysis Methods: Prepared samples are suitable for laboratory analyses using:
  • Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
  • Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
  • Flame Atomic Absorption Spectrometry (FAAS)
  • Graphite Furnace Atomic Absorption Spectrometry (GFAAS)
• Quality Control: Emphasizes the use of certified reference materials, blanks, spiked samples, and control charts to assess method accuracy and reduce contamination risk.
• Compliance and Safety: Users are responsible for implementing appropriate safety, health, and environmental protocols in line with regulatory requirements.

Applications

ASTM D8404-21 is widely applicable in various scenarios where monitoring of metals and metalloids in soil is necessary:

• Hazard Assessment: Preparation of soil samples from construction, renovation, and hazard survey activities in and around buildings to determine potential contamination threats.
• Environmental Monitoring: Evaluation of soils near transportation infrastructure, steel structures, and other potentially contaminated sites.
• Remediation Effectiveness: Supports monitoring strategies for assessing the success of soil remediation and cleanup activities.
• Regulatory Compliance: Aids laboratories in meeting federal, state, and international guidelines for reporting and controlling environmental pollutants in soil.
• Broader Industrial Use: Suitable for geotechnical, agricultural, and waste management studies where metals and metalloids analysis is essential.

Related Standards

To ensure robust, reliable results, ASTM D8404-21 references and complements several key standards and methods:

• ASTM D3974: Practices for Extraction of Trace Elements from Sediments
• ASTM D4840: Guide for Sample Chain-of-Custody Procedures
• ASTM D7202: Test Method for Determination of Beryllium in the Workplace
• ASTM D8344: Practice for Ammonium Bifluoride and Nitric Acid Digestion of Airborne Dust and Dust-Wipe Samples
• U.S. EPA SW 846, Test Method 3050: Test Methods for Evaluating Solid Waste
• ISO/IEC 17025: General requirements for the competence of testing and calibration laboratories
• ISO Guide 30: Terms and Definitions Used in Connection with Reference Materials

By utilizing ASTM D8404-21 and ensuring compatibility with related standards, laboratories can achieve accurate, reproducible, and internationally recognized soil sample preparation and analysis for metals and metalloids.

Keywords: ASTM D8404-21, soil sample preparation, ammonium bifluoride-nitric acid digestion, metals and metalloids analysis, environmental hazard assessment, soil contamination, quality control, ICP-MS, ICP-AES, FAAS, GFAAS, laboratory standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D8404 −21
Standard Practice for
Preparation of Soil Samples by Ammonium Bifluoride-Nitric
Acid Digestion for Subsequent Analysis for Metals and
Metalloids
This standard is issued under the fixed designation D8404; 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 2. Referenced Documents
1.1 This practice covers drying, homogenization, and am- 2.1 ASTM Standards:
monium bifluoride-nitric acid digestion of soil samples and D653Terminology Relating to Soil, Rock, and Contained
associated quality control (QC) samples for the determination Fluids
of metals and metalloids using laboratory atomic spectrometry D1129Terminology Relating to Water
analysis techniques such as inductively coupled plasma mass D1193Specification for Reagent Water
spectrometry (ICP-MS), inductively coupled plasma atomic D1356Terminology Relating to Sampling and Analysis of
emission spectrometry (ICP-AES), flame atomic absorption Atmospheres
spectrometry (FAAS), and graphite furnace atomic absorption D3974Practices for Extraction of Trace Elements from
spectrometry (GFAAS). For ammonium bifluoride-nitric acid Sediments
digestion of airborne dust and dust-wipe samples for the D4840Guide for Sample Chain-of-Custody Procedures
determination of metals and metalloids, see Practice D8344. D7202Test Method for Determination of Beryllium in the
WorkplacebyExtractionandOpticalFluorescenceDetec-
1.2 This practice is based on U.S. EPA SW 846, Test
tion
Method 3050, Test Method D7202, and Practice D8344.
D8344Practice for Ammonium Bifluoride and Nitric Acid
1.3 Thispracticecontainsnotesthatareexplanatoryandare
Digestion of Airborne Dust and Dust-Wipe Samples for
not part of the mandatory requirements of this standard.
the Determination of Metals and Metalloids
1.4 The values stated in SI units are to be regarded as E288Specification for Laboratory Glass Volumetric Flasks
E882Guide for Accountability and Quality Control in the
standard. The values given in parentheses after SI units are
providedforinformationonlyandarenotconsideredstandard. Chemical Analysis Laboratory
E1154Specification for Piston or Plunger Operated Volu-
1.5 This standard does not purport to address all of the
metric Apparatus
safety concerns, if any, associated with its use. It is the
E1605Terminology Relating to Lead in Buildings
responsibility of the user of this standard to establish appro-
E1727Practice for Field Collection of Soil Samples for
priate safety, health, and environmental practices and deter-
Subsequent Lead Determination
mine the applicability of regulatory limitations prior to use.
2.2 U.S. Government Analytical Method:
1.6 This international standard was developed in accor-
U.S. EPASW 846Test Methods for Evaluating Solid Waste
dance with internationally recognized principles on standard-
Physical/Chemical Methods
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
ThispracticeisunderthejurisdictionofASTMCommitteeD22onAirQuality the ASTM website.
and is the direct responsibility of Subcommittee D22.04 on WorkplaceAir Quality. AvailablefromUnitedStatesEnvironmentalProtectionAgency(EPA),William
Current edition approved Sept. 1, 2021. Published October 2021. DOI: 10.1520/ Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
E8404-21. http://www.epa.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8404−21
2.3 ISO Standards: 3.1.8.1 Discussion—Analysis results for these samples are
ISO Guide 30Terms and Definitions Used in Connection used to provide information on the precision and accuracy of
with Reference Materials the overall process.
ISO 1042Laboratory glassware — One-mark volumetric
4. Summary of Practice
flasks
ISO/IEC 17011Conformity assessment—Requirements for 4.1 Arepresentative soil sample is dried and homogenized,
accreditation bodies accrediting conformity assessment andthendigested(inabatchmodewithothersamples)inahot
blockusingammoniumbifluorideandnitricacid.Thedigestate
ISO/IEC 17025General requirements for the competence of
testing and calibration laboratories isdilutedforfinalvolumepriortomeasurementformetalsand
metalloids.
3. Terminology
5. Significance and Use
3.1 Definitions—For definitions of terms relating to the
5.1 There is a need to monitor the content of metals and
preparation of soil samples that are not given here, refer to
metalloids in order to determine the presence of potential
Terminologies D653, D1129, D1356,or E1605.
hazards.Hence,effectiveandefficientmethodsarerequiredfor
3.1.1 batch, n—a group of field or quality control samples
thepreparationofsoilsamplesfordeterminationofmetalsand
that are processed together using the same reagents and
metalloids present therein.
equipment.
5.2 This practice may be used for the digestion of soil
3.1.2 digestate, n—the acidified aqueous solution that re-
samples that are collected during various construction and
sults from digestion of the sample.
renovationandhazardsurveyactivitiesinandaroundbuildings
3.1.3 digestion, n—high temperature sample preparation
and related structures. The practice is also suitable for the
process that involves chemical breakdown to solubilize tar-
digestion of soil samples for metal and metalloid analyses
geted analytes present in a sample.
collected from other locations, such as near roads and steel
structures. For some other extraction procedures, see Practices
3.1.4 method blank, n—a sample, devoid of analyte, that is
D3974.
analyzed to determine its contribution to the total blank
(background) reading.
5.3 This practice is intended to be used to prepare samples
that have been collected for hazard assessment purposes but
3.1.5 non-spiked sample, n—a sample, devoid of analyte,
may be used for other applications such as, for example,
that is targeted for addition of analyte but is not fortified with
monitoring the effectiveness of remediation activities.
all target analytes prior to sample preparation.
3.1.5.1 Discussion—Analysis results for this sample are
5.4 This practice may be capable of determining metals and
usedtocorrectforbackgroundlevelsintheblankmediumthat
metalloids bound within matrices, such as silica, that are not
is used for spiked and spiked duplicate samples.
soluble in nitric acid alone.
3.1.6 reagent blank, n—a digestate that reflects the maxi-
5.5 This practice includes drying and homogenization steps
mum treatment given any one sample within a batch of
to help assure that reported results are representative of the
samples, except that it has no sample placed initially into the
sample and are independent of potential differences in soil
digestionvessel.(Thesamereagentsandprocessingconditions
moisture levels among different sampling locations or chang-
thatareappliedtofieldsampleswithinabatcharealsoapplied
ing weather conditions.
to the reagent blank.)
6. Reagents and Materials
3.1.6.1 Discussion—Analysis results from this sample pro-
vide information on the level of potential contamination
6.1 Equipment:
resulting from only laboratory sources that are experienced by
6.1.1 Analytical Balance,capableofaccuratelydetermining
samples processed within the batch.
the mass to the nearest 0.001 g.
6.1.2 Drying Oven, preferably a gravity convection type
3.1.7 reference material (certified reference material)
capable of maintaining a temperature of 100 °C to 120 °C.
(CRM), n—reference material accompanied by a certificate,
6.1.3 Grinding Apparatus—Mortar and pestle (porcelain or
one or more of whose property values are certified by a
agate), shatter box, or mixer mill.
procedure which establishes its traceability to an accurate
6.1.4 Micropipettors with Disposable Plastic Tips conform-
realization of the unit in which the property values are
ing to Specification E1154, sizes needed to make reagent
expressed; each certified value is accomplished by an uncer-
additions, and spiking standards.
tainty at a stated level of confidence. ISO Guide 30
NOTE 1—In general, the following sizes should be readily available: 1
3.1.8 spiked sample or spiked duplicate sample, n—a
mL to 5 mL adjustable, 1000 mL, 500 mL, 250 mL, and 100 mL.
sample portion (split from an original sample) that is spiked
with a known amount of analyte. 6.1.5 Sieves, 4.75 mm (U.S. Standard No. 4), 2 mm (No.
10), and 500 mm (No. 35), plastic or stainless steel. When
sievescontainingsolderedjointsareused,thenallsolderjoints
shallbecoatedwithepoxyresinpriortousetoprotectsamples
Available from International Organization for Standardization (ISO), ISO
from potential lead contamination originating in the solder.
Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, https://www.iso.org. Visually inspect prior to use for the presence of bare metal.
D8404−21
NOTE 2—Plastic or stainless steel sieves are better for use instead of
6.2.3 Calibration Stock Solutions—1000 mg/mL of the
brass sieves to alleviate possible lead contamination of the soil samples
metal, metals, or metalloids of interest in dilute nitric acid
from contact with lead solder common to brass sieves.
obtained from a commercial supplier accredited to ISO/IEC
6.1.6 Thermometers,thatcoverarangefrom0°Cto110°C.
17025 by an accreditation body complying with ISO/IEC
6.1.7 Plastic Gloves, powderless.
17011.
6.1.8 Air-Tight Sample Containers, 1 L(1 qt) or 4 L(1 gal)
6.2.4 Extraction (or Dissolution) Solution—Mass fraction 1
re-sealable plastic bags, or plastic 50 mL centrifuge tubes.
% ammonium bifluoride (NH HF ) solution (aqueous) for
4 2
6.1.9 Tongs, metal.
dissolution of metals and metalloids in collected particulate
6.1.10 Spoon, stainless steel or plastic, or both.
matter.(Warning—Ammoniumbifluoridewilletchglass,soit
6.1.11 Heat Block, controllable to maintain the specified
is essential that all NH HF solutions be contained in plastic
4 2
digestion temperature in wells sized to accept the screw top
labware.)
plastic centrifuge tubes used for the digestion.
6.2.5 Nitric Acid—Redistilled, concentrated nitric acid, 16
6.1.12 Centrifuge Tubes, plastic, 50-mL, with screw top
N, specific gravity 1.42.
caps.
6.2.6 Acetone—Reagent grade.
6.1.13 Labware, plastic (for example, beakers, flasks,
graduated cylinders, etc.), of assorted sizes as needed. 7. Equipment Preparation
6.1.14 Forceps, plastic or plastic-coated.
7.1 Wash glassware and plastic equipment with laboratory
6.1.15 Syringes.
detergent, rinsed with tap water, soak for at least 4 hours in
volume fraction 35 % nitric acid and water, rinse three times
NOTE3—Thefiltrationprocesscanbecarriedoutbyattachinga25-mm
diameter syringe filter to Luer lock syringes and pouring the liquid
withASTMTypeIWater,andallowtodrypreferablyinafume
contents into the syringe. The liquid is forced out through the filter into a
hood. Commercial, automatic systems are available that per-
separate 50-mL centrifuge tube.
form a similar process.
6.1.16 Microfilters.
7.2 Alternatively, soak glassware and plastic equipment in
NOTE4—Filterswith0.2to0.45-µmporesizeareacceptable.Preferred
volume/volume 1+1 nitric acid and water in a plastic tub
filters are made out of nylon, polyethersulfone, or hydrophilic polypro-
preferably in a working hood with the hood sash down, rinse
pylene. Polytetrafluoroethylene (PTFE) filters are unsuitable because they
three times with ASTM Type I Water, and allow to dry
may partially dissolve in ammonium blifluoride solution during filtration.
preferably in a fume hood.
6.1.17 Borosilicate Glassware—Volumetric flasks with
stoppers meeting Specification E288 or conforming to ISO
8. Procedure
1042, 100 mL; Griffin beakers, 100 mL, 150 mL or 250 mL;
8.1 Sample Pre-treatment:
watch glasses sized to cover Griffin beakers.
8.1.1 Treat each sample in a processing batch equally.
6.1.18 Air-Tight Sample Containers—1 L (1 qt) or 4 L (1
8.1.2 If possible before removal, break up the soil sample
gal) re-sealable plastic bags, or plastic 50 mLcentrifuge tubes.
within the original containers containing the samples as re-
6.1.19 Volumetric Flasks, meeting Specification E288 or
ceived from the sampler.
conforming to ISO 1042, 100 mLand other sizes as needed to
NOTE 5—This will not be possible for wet soil samples.
make dilutions of sample digests or standards.
6.1.20 Spoon, stainless steel.
8.1.3 Labela100mL,150mL,or250mLGriffinbeaker(or
6.1.21 Other general laboratory apparatus, as needed.
other vessel suitable for oven drying of soils that will not
contaminate the sample with metals or metalloids of interest)
6.2 Reagents:
with a high temperature wax pen or any other marker that will
6.2.1 Purity of Reagents—Reagent grade chemicals shall be
be visible after exposure to the drying oven.
used in this practice. Unless otherwise indicated, it is intended
8.1.4 Transfer the entire soil sample to the labeled Griffin
thatallreagentsconformtothespecificationsoftheCommittee
beaker. Cover with a watch glass (tip to one side to permit
on Analytical Reagents of the
...