ASTM D6323-19

Standard Guide for Laboratory Subsampling of Media Related to Waste Management Activities

SIGNIFICANCE AND USE
4.1 This guide discusses options for taking a subsample from a sample submitted to a laboratory. If followed, it will minimize the bias and variance of the characteristic of interest of the laboratory sample prior to analysis.  
4.2 The guide will describe appropriate instructions to be submitted to the laboratory with the field sample.  
4.3 This guide is intended for use in the laboratory to take a representative subsample or specimen of the whole field sample for direct analysis or sample preparation for analysis. It is intended for field personnel, data users, laboratory sample reception personnel, analysts, and managers.  
4.4 To obtain a representative subsample, layer analysis, grinding, mixing, and changing the physical state such as digesting, drying, melting, or freezing may be required. This guide considers cone and quartering, riffle splitting, and particle size reduction.
SCOPE
1.1 This guide covers common techniques for obtaining representative subsamples from a sample received at a laboratory for analysis. These samples may include solids, sludges, liquids, or multilayered liquids (with or without solids).  
1.2 The procedures and techniques discussed in this guide depend upon the sample matrix, the type of sample preparation and analysis performed, the characteristic(s) of interest, and the project-specific instructions or data quality objectives.  
1.3 This guide includes several sample homogenization techniques, including mixing and grinding, as well as information on how to obtain a specimen or split laboratory samples.  
1.4 This guide does not apply to air or gas sampling.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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-Jan-2019
• ICS: 13.030.01 - Wastes in general
• Technical Committee: D34 - Waste Management
• Drafting Committee: D34.01.01 - Planning for Sampling

Relations

• Replaces: ASTM D6323-12e1 - Standard Guide for Laboratory Subsampling of Media Related to Waste Management Activities (Withdrawn 2018)
• Effective Date: 01-Feb-2019
• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM D5681-23 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2023
• Refers: ASTM D2234/D2234M-19 - Standard Practice for Collection of a Gross Sample of Coal
• Effective Date: 01-Dec-2019
• Refers: ASTM D4823-95(2019) - Standard Guide for Core Sampling Submerged, Unconsolidated Sediments
• Effective Date: 01-Nov-2019
• Refers: ASTM D5681-18 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2018
• Refers: ASTM D2234/D2234M-17 - Standard Practice for Collection of a Gross Sample of Coal
• Effective Date: 15-Oct-2017
• Refers: ASTM D5681-17 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Sep-2017
• Refers: ASTM D5681-16a - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2016
• Refers: ASTM D2234/D2234M-16 - Standard Practice for Collection of a Gross Sample of Coal
• Effective Date: 01-Mar-2016
• Refers: ASTM D5681-16 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Feb-2016
• Refers: ASTM D4547-15 - Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds
• Effective Date: 01-Sep-2015
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM D4823-95(2014) - Standard Guide for Core Sampling Submerged, Unconsolidated Sediments
• Effective Date: 01-Jan-2014

Overview

ASTM D6323-19: Standard Guide for Laboratory Subsampling of Media Related to Waste Management Activities provides essential guidance for laboratories and waste management professionals on how to obtain representative subsamples from field samples received for analysis. Issued by ASTM International, this standard aims to reduce bias and variance in analytical results by specifying systematic procedures for subsampling various types of environmental media, such as solids, sludges, liquids, and multi-layered liquids (excluding air or gas samples).

By following ASTM D6323-19, laboratories can ensure reliable and consistent data in waste characterization, site assessments, and regulatory compliance, supporting the highest standards of scientific accuracy in waste management activities.

Key Topics

• Representative Subsampling: The guide describes how to select portions of a field sample that accurately reflect its characteristics, minimizing sample bias.
• Sample Matrix Considerations: Procedures vary depending on the sample type, including solids, liquids, sludges, and multi-layered liquids-each with unique handling requirements.
• Homogenization Techniques: Methods such as mixing, grinding, and sample splitting (including cone and quartering or riffle splitting) help ensure uniformity before analysis.
• Particle Size Reduction: Guidance on when and how to reduce particle size to achieve accurate subsample representation, especially when dealing with heterogenous waste materials.
• Physical State Changes: Instructions for preparing subsamples through drying, melting, freezing, or digesting to facilitate analysis.
• Laboratory and Field Personnel Roles: The standard outlines responsibilities and communication protocols between data users, field staff, laboratory reception, analysts, and managers.
• Documentation and Quality Assurance: Emphasizes the need to record methods used and communicate any deviations or conditions affecting sample integrity.

Applications

ASTM D6323-19 is widely applicable across industries and activities involving environmental waste management and laboratory analysis. Key applications include:

• Environmental Site Assessments: Ensuring accurate laboratory analysis of soil, sediment, sludge, or liquid waste from contaminated sites or remediation projects.
• Waste Characterization: Supporting industrial and municipal waste testing for regulatory compliance and disposal requirements.
• Hazardous Waste Management: Facilitating the analysis of multi-phase waste (e.g., oil-water mixtures, slurries) to meet environmental protection standards.
• Quality Control in Laboratories: Establishing standardized procedures for laboratory staff to minimize analytical errors and improve data reliability.
• Research and Development: Assisting scientists and researchers in preparing representative samples for studies involving contaminated media.

Adherence to this standard helps minimize uncertainties in test results, supports regulatory compliance, and enhances the credibility of reported data in environmental and waste management sectors.

Related Standards

Several other standards complement or provide additional guidance alongside ASTM D6323-19:

• ASTM C702/C702M: Practice for Reducing Samples of Aggregate to Testing Size.
• ASTM D2234/D2234M: Practice for Collection of a Gross Sample of Coal.
• ASTM D346/D346M: Practice for Collection and Preparation of Coke Samples for Laboratory Analysis.
• ASTM D4547: Guide for Sampling Waste and Soils for Volatile Organic Compounds.
• ASTM D5743: Practice for Sampling Single or Multilayered Liquids in Drums or Similar Containers.
• ASTM D6051: Guide for Composite Sampling and Field Subsampling for Environmental Waste Management Activities.
• ASTM D5681: Terminology for Waste and Waste Management.

For effective laboratory subsampling of media in waste management, ASTM D6323-19 and these related standards provide a comprehensive framework ensuring sample integrity from field collection through laboratory analysis. This reduces variability, supports data quality objectives, and upholds compliance with environmental regulations.

Keywords: ASTM D6323-19, laboratory subsampling, waste management, environmental media, representative sample, sample homogenization, particle size reduction, laboratory best practices, waste analysis 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: D6323 − 19
Standard Guide for
Laboratory Subsampling of Media Related to Waste
Management Activities
This standard is issued under the fixed designation D6323; 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 C702/C702M Practice for Reducing Samples of Aggregate
to Testing Size
1.1 This guide covers common techniques for obtaining
C859 Terminology Relating to Nuclear Materials
representative subsamples from a sample received at a labora-
D346/D346M Practice for Collection and Preparation of
tory for analysis. These samples may include solids, sludges,
Coke Samples for Laboratory Analysis
liquids, or multilayered liquids (with or without solids).
D2234/D2234M Practice for Collection of a Gross Sample
1.2 The procedures and techniques discussed in this guide
of Coal
depend upon the sample matrix, the type of sample preparation
D4547 Guide for Sampling Waste and Soils for Volatile
andanalysisperformed,thecharacteristic(s)ofinterest,andthe
Organic Compounds
project-specific instructions or data quality objectives.
D4823 Guide for Core Sampling Submerged, Unconsoli-
1.3 This guide includes several sample homogenization dated Sediments
D5681 Terminology for Waste and Waste Management
techniques, including mixing and grinding, as well as informa-
tion on how to obtain a specimen or split laboratory samples. D5743 Practice for Sampling Single or Multilayered
Liquids, With or Without Solids, in Drums or Similar
1.4 This guide does not apply to air or gas sampling.
Containers
1.5 The values stated in SI units are to be regarded as
D6051 Guide for Composite Sampling and Field Subsam-
standard. No other units of measurement are included in this
pling for Environmental Waste Management Activities
standard.
3. Terminology
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1 Definitions—For definitions of terms used in this guide,
responsibility of the user of this standard to establish appro-
refer to Terminology D5681.
priate safety, health, and environmental practices and deter-
3.2 Definitions of Terms Specific to This Standard:
mine the applicability of regulatory limitations prior to use.
3.2.1 contaminant unit, n—the largest particle size that
1.7 This international standard was developed in accor-
contains the contaminant of interest
dance with internationally recognized principles on standard-
3.2.1.1 Discussion—The contaminant of concern, as defined
ization established in the Decision on Principles for the
by the project objectives, may be associated with all the
Development of International Standards, Guides and Recom-
particle sizes or associated with only a certain particle size or
mendations issued by the World Trade Organization Technical
sizes. At the time of waste generation, discharge, or spill, the
Barriers to Trade (TBT) Committee.
particle size of this contaminant of concern may be on the
atomic or molecular scale, such as solvent spill into sand, or a
2. Referenced Documents
macroscale, such as lead acid batteries at a dump site. The
2.1 ASTM Standards:
contaminant unit may also be in between these scales, such as
leadparticlesencapsulatedincoal.Inpractice,thecontaminant
unit may change if the contaminant unit becomes absorbed or
This guide is under the jurisdiction of ASTM Committee D34 on Waste
adsorbed to particles larger than the contaminant unit. It is the
Management and is the direct responsibility of Subcommittee D34.01.01 on
Planning for Sampling. size of the contaminant unit at the time of subsampling, not at
Current edition approved Feb. 1, 2019. Published February 2019. Originally
the time of generation, that is referred to as the contaminant
ɛ1
approved in 1998. Last previous edition approved in 2012 as D6323 – 12 , which
unit.
was withdrawn in October 2018 and reinstated in February 2019. DOI: 10.1520/
D6323-19.
3.2.2 maximum allowable particle size, n—the largest lineal
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dimension of a sample’s individual particles accepted for a
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
given sample mass.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 3.2.2.1 Discussion—The maximum allowable particle size
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6323 − 19
issometimesreferredtoastheallowableparticlesize.Asimple discussed and clarified prior to initiating any subsampling
method of measurement is a sieve. procedure. These instructions may include such options as
those found in Table 1.The limitations and advantages of these
3.2.3 multilayered sample, n—a sample consisting of two or
methods are also found in this table. The data user should be
more clearly differentiated components.
informed about the limitations and advantages of all subsam-
3.2.3.1 Discussion—Multilayered samples are those with
pling procedures prior to deciding which one to use.
twoormoredistinctvisuallayersofmaterial.Theselayersmay
5.1.2 If the data user still provides no instructions upon
be the result of differences in density, such as liquid/liquid
being contacted, laboratory personnel should explain to the
layers (for example, chlorinated solvents and water, water and
data user that the laboratory’s standard operating procedures,
oil), liquid/solid layers (for example, sludge), solid/solid layers
which reflect the concerns and issues discussed in this
(for example, small rocks and large rocks), or combinations of
standard, will be used. The sample should be treated as if the
these layers (for example water, oil, and soil). These layers
scale of the contamination is on the micro level, and no
may also be the result of depositional layering, such as green
artifacts can be removed. Since sample matrices and types and
clay and silty sand from a coring sample.
mechanisms of contamination are infinitely variable and re-
3.2.4 particle size, n—the controlling lineal dimension of
quire judgments to be made, it is advisable that experienced
individual particles (see Terminology C859).
analysts decide which subsampling techniques be employed.
3.2.5 representative subsample, n—a subsample collected in
These procedures must be discussed and clarified with the data
such a manner that it reflects one or more characteristics of
user prior to initiating any subsampling procedure.
interest (as defined by the project objectives) of the laboratory
5.2 If the sample integrity or composition is not as
sample from which it was collected.
anticipated, the data user must be contacted to confirm or
3.2.5.1 Discussion—A representative subsample can apply
clarify the instructions. An example of when this would be
to a single sample, or a composite sample.
necessary would be a case where a coring sleeve was received
3.2.6 sludge, n—any mixture of solids that settles out of
at the laboratory. On opening the container, the analyst notices
solution. Sludges contain liquids that are not apparent as free
clay in one end of the sleeve, and sand at the other end. Before
liquids (see Practice D5743).
the analyst can proceed, the appropriate instructions from the
data user must be obtained.
4. Significance and Use
5.2.1 Field samples should be collected in appropriate
4.1 This guide discusses options for taking a subsample
containers for the analyses requested. If the submitted sample
from a sample submitted to a laboratory. If followed, it will
is improperly collected, the data user should be contacted by
minimize the bias and variance of the characteristic of interest
laboratory personnel. If the data user authorizes the laboratory
of the laboratory sample prior to analysis.
to continue with the analysis, a note should be made in the
4.2 The guide will describe appropriate instructions to be receival documentation and also in the case narrative in the
submitted to the laboratory with the field sample. final report.
4.3 This guide is intended for use in the laboratory to take a
5.3 Documentation during the subsampling process is criti-
representative subsample or specimen of the whole field
cal. Since subsampling techniques may bias the results, the
sample for direct analysis or sample preparation for analysis. It
subsampling method used must be noted in the analytical
is intended for field personnel, data users, laboratory sample
logbook.
reception personnel, analysts, and managers.
5.3.1 Anytime the analytical result will be biased, it must be
documented, and the data user should be notified prior to
4.4 To obtain a representative subsample, layer analysis,
beginning any subsampling technique. For example, if head-
grinding, mixing, and changing the physical state such as
space exists in a container arriving at the laboratory, some
digesting, drying, melting, or freezing may be required. This
volatile components will have partitioned into that headspace.
guide considers cone and quartering, riffle splitting, and
However, if the data user decides to proceed with the analysis,
particle size reduction.
the analytical logbook and the case narrative on the final report
should indicate this condition.
5. General Considerations
5.1 Successful implementation of this standard depends on 5.4 Particle size is the physical dimension of an object’s
effective communication between the data user and the labo- pieces or parts. The maximum particle size contained within a
ratory staff. The selection of optimal subsampling procedures, laboratory sample is the largest of these pieces. The contami-
techniques, and strategy by the laboratory depends on the nant of concern, as defined by the project objectives, may be
intended use of the data. The data user should submit appro- associated with all particle sizes or associated with only a
priate instructions with all samples and, when necessary, the certain particle size or sizes. The largest of these particle sizes
laboratory staff should contact the data user for confirmation or that contains the contaminant of interest would be the contami-
further clarification of these instructions. nant unit. The contaminant unit, at the time of waste
5.1.1 Theappropriateinstructionsmustbereviewedbyboth generation, discharge, or spill, may be on the atomic or
the laboratory receiving personnel and the analyst(s) or super- molecular scale, such as a solvent spill into sand, or a
visor. If there are no instructions, the appropriate laboratory macroscale, such as lead acid batteries at a dump site. The
personnel should contact the data user. Options should be contaminant unit may also be in between these scales, such as
D6323 − 19
TABLE 1 Limitations and Advantages of Sample Preparation Options
Instruction Limitations Advantages
Remove artifacts, such as rocks and twigs, from the (1) May bias analytical results by altering contaminant (1) May be easier to subsample, (2) May be easier to
sample prior to subsampling concentration, (2) May bias sample if results are not analyze, (3) Appropriate if the target population is
properly weight averaged. material minus artifacts.
Digest or extract the contaminant from the outside May bias sample if contaminant is within the large (1) May be easier to analyze, (2) May prevent need
A
of the large particles particles. for weight average calculation.
A
Digest or extract particle sizes separately (1) Separation of particle sizes may be difficult, (1) Allows some particle size consistency during
(2) May bias sample if results are not properly weight
analysis, (2) May be easier to subsample within
averaged, (3) Higher cost.
portions after separation.
Form an emulsion layer so that the material may May bias the sample if a complete emulsion is not (1) May be easier to subsample as a homogeneous
A
be treated as homogeneous liquid achieved. liquid,
Separate liquid layers (1) Separation of layers may be difficult, especially (1) May be easier to analyze, (2) May be easier to
at the interface, (2) May bias sample if results are subsample within portions after separation, (3) Allows
not properly weight averaged. different preparation methods within each layer.
Dry sample May alter chemistry or change stability of some (1) Allows for consistency of subsampling for liquid/
A
compounds. solid mixtures, (2) Analytes reported unbiased by
moisture content.
Change the physical state, such as freeze the May be difficult to achieve complete freezing or Allows for consistency of subsampling.
material so that it may be treated as a solid, or melting and maintain it long enough to get a
A
melt the material so that it may be treated as a subsample.
liquid
Analyze only one layer of multilayered samples, May bias the sample if there is cross-contamination (1) Possible cost savings to customer, (2) May be
such as analyze only the oil portion of an oil/water between layers easier to subsample from a single layer, (3) May be
mixture for PCBs easier to analyze.
Composite portions of the sample for volatile (1) May overload gas chromatography columns if (1) May prevent losses of volatile because the sample
analysis directly in a purge unit vs. individual sample has high amounts of solvents in each portion, is handled only once, (2) Possible cost savings to
analysis of these portions (2) Separation of portions may be difficult. customer, (3) May prevent need for weight average
calculation.
Reduce particle size (1) Increasing surface area may effect data in some Allows for consistency of subsampling.
procedure with particle digestion or extraction, such
A
as TCLP, (2) May be difficult, depending on matrix.
A
Use standard methods for solids (for example, Dependent on method. See 7.1.5 for more Dependent on method. See 7.1.5 for more information.
information.
cone and quarter, grind, riffle, sieve)
A
May be unsuitable for samples to be analyzed for volatile constituents.
leadparticlesencapsulatedincoal.Inpractice,thecontaminant extracts/digests combined and mixed prior to removal of the
unit may change if the contaminant becomes absorbed or standard volume specimen needed for analysis. Another alter-
adsorbed to particles larger than the contaminant unit. native is to reduce the particle size of the entire sample or
5.4.1 Knowledge of the contaminant unit may be used to subsample as specified by sampling theory. If the particle size
determine the preliminary steps to subsampling. For example, is reduced enough, a subsample of the mass recommended by
if the contaminant unit is on a molecular scale and was sampling theory and the extraction/digestion method can be
adsorbed to soil particles and rocks, removal of large rocks obtained.
with their relatively small surface area may not affect the data
5.6 All subsampling should be performed in an area which
as long as the results are weight averaged. If one is unsure of
is free from contamination, easily decontaminated, and vented
the mechanism of contamination that determines how the
to control dust and remove fumes.
contamination is dispersed within the sample matrix, one may
5.7 Prior to subsampling liquids, the analyst must consider
not be able to discard any particles during subsampling.
the property or characteristic requested, and the container size
5.5 Sampling theory requires that subsample mass should
received. If the analyte has the ability to adsorb onto the
increase as the size of the largest particle in the sample
container, the field sample should arrive at the laboratory in an
increases. If the subsample mass recommended by sampling
appropriately sized bottle, such that the whole sample will be
theory is larger than that normally used in the sample prepa-
used. The sides of the container should then be rinsed properly
ration method, the subsample mass may be increased and the
to ensure that all the contaminants are transferred into the
extraction/digestion procedure scaled accordingly. The stan-
analytical vessel.
dard volume of digestate/extract is then submitted for analysis.
However, if the subsample mass is too large to be accommo- 5.8 Subsampling techniques are different when analyzing
dated by the sample preparation procedure, multiple sub- for volatile compounds than non-volatile compounds. The
samples (of equal mass) can be extracted/digested, and the differences are discussed for each sample matrix.
D6323 − 19
6. Matrix-Specific Subsampling (for example, a solvent is discharged to soil), an argument can
be made to preclude large particles (for example, rocks), since
6.1 Solids:
insignificant amounts of contamination will be adsorbed to the
6.1.1 Table 2 gives the relationship between the maximum
small surface of the large particles. If the large particles are
particlesizeandsamplemasstoachieveafundamentalerrorof
3 excluded, the appropriate mass can be based on the smaller
15 %. For information about fundamental error, see Ref (1). If
particle sizes, which have a much larger surface area. If the
the maximum allowable particle size is greater than that listed
decisionismadetoremovethelargeparticles,themassofboth
in the table, then sampling theory would suggest particle size
the large and small particles would be used to calculate the
reduction, such as grinding, or use of a larger sample mass. For
final concentration of the contaminant of interest.
example, if granule gravel has an allowable particle size of
6.1.2 If larger sample masses are required, two ASTM
0.21 cm, according to this table, a subsample mass of 10 g is
standards may be helpful. Practice D2234/D2234M discusses
needed. Many digestions/extractions commonly use 1 g. The
test methods and procedures for the collection of a sample
10-g subsample would be ground to a size of 0.1 cm, and the
under various conditions of sampling. It describes general and
specimen would be taken from the ground material. Approxi-
special-purpose sampling procedures for coal by size,
mations were employed to construct this table. The actual
condition, and characteristics. The document also includes in
fundamental error could be much larger. More information on
the annex a test method for determining the variance of
calculating the maximum allowable particle size for various
components of a coal and a test method for estimating the
fundamental errors, and particles shapes is included in Annex
overall variance for increments of one fixed weight of a given
A1.
coal.
6.1.1.1 Particle size reduction can be avoided by modifying
6.1.2.1 Asecond method which is often referenced by other
the sample digestion/extraction methods to use large specimen
ASTM standards dealing with coals is Practice D346/D346M.
masses. Following digestion/extraction of the large specimen,
The practice is designed to provide a representative sample of
the homogeneous digestate/extract is analyzed. For example, if
the coke from which it is collected. It considers the variability
the contaminant of concern was a chromium solution spilled
of coke and the wide variety of sampling equipment.
into a mixture of gravel and soil, knowing that the chromium
6.1.3 If the desired subsample mass is equal to or less than
coats the medium allows a choice of sample preparation. The
themaximumallowableparticlesize,subsamplingcanproceed
analyst may totally dissolve the specimen. He/she may digest
without any need for particle size reduction. If the particle size
the chromium from the outside of the particles, analyzing the
is greater than the allowable particle size in Table 2, then the
digestate. Or, he/she may extract the material, and analyze the
sample matrix, the type and mechanism of contamination, the
extractant. If the analyst had no information about the mecha-
scale of the contaminant unit, as well as particle size reduction
nism of contamination, he/she would have to assume that the
should be considered. These allowable particle sizes are based
contamination is throughout all particles of the laboratory
on the assumption that the contaminant exists as a particle or is
sample.
adsorbed to particles. In those cases where the contaminant
6.1.1.2 If information is available regarding the type and
unit is on the atomic or molecular scale or is a particle much
mechanism of contamination, then it may be possible to avoid
smaller than the allowable particle size of the sample, then
particle size reduction and the use of large specimen masses.
alternative approaches can be employed with acceptable bias.
For example, if contamination occurred on a molecular level
6.1.4 Solid Samples for Volatile Analysis:
6.1.4.1 Due to the volatility of this class of compounds,
laboratory subsampling procedures addressing the sample’s
The boldface numbers given in parentheses refer to a list of references at the
allowable particle size could result in large losses of the
end of the text.
parameter of interest, rendering the results unrepresentative.
The possible exception is when cryogenic freezing conditions
TABLE 2 Recommended Minimum Subsample Mass for
are maintained throughout the handling process.
Particulate Materials to Achieve a Fundamental Error of 15 %
Recommended Maximum
NOTE 1—If cryogenic techniques (working with frozen samples) or
U.S. Standard
Minimum Allowable
B
other special techniques are used, the procedure should be validated on
Size Class Sieve Mesh
A
Subsample Particle Size,
Size
laboratory control samples (LCS) which have been spiked with known
cm
Mass, g
concentrates of the parameter of interest. The nature of the test matrix for
0.1 0.05 Clay to coarse sand 35
the LCS and the spiking solution should be chosen to allow uniform
1 0.1 Coarse to very coarse sand 18
distribution of the spike in the matrix prior to subsampling. Regardless of
2 0.13 Very coarse sand 13
5 0.17 Very coarse sand 12 the particle size reduction techniques chosen, it is advisable to carry an
10 0.21 Granule gravel 10
LCS through each preparation batch as a quality control sample. A
30 0.31 Granule gravel 7
subsample of the field sample without particle size reduction through the
50 0.37 Granule gravel 6
validation procedure will demonstrate the amount of volatile loss (from
100 0.46 Pebble gravel 5
the LCS results) and increased volatiles recovery (from a comparison of
A
The maximum allowable particle size allowed can be approximated for other the unreduced field sample with the size reduced sample) using particle
sample masses by using the equation, allowable particle size (cm) = the cube root
size reduction.)
of 0.001 × sample mass in grams.
B
Wentworth Size Class (see (2) and (3)). These soil descriptions are added for 6.1.4.2 When analyzing samples for low levels of volatile
those readers who equate particle size with the Wentworth descriptions and are
constituents (0.5 to 200 µg/kg range), discreet samples should
not meant to indicate that the application of this table is limited to soil particles. The
beplacedintoacontainerthat,oncesealed,isanalyzedwithout
table can also be used for non-soil particles such as waste.
opening (see Guide D4547). For this reason, and because
D6323 − 19
sample mass is often limited by the analysis system, low-level requiring a vessel with 250 mL of solvent.As an alternate to a
samples typically are not amenable to either particle size single large sample, five 20-g subsamples could be extracted.
reduction procedures or the analysis of larger sample mass. Microliter amounts of each of the five resulting extracts could
When contaminant levels exceed 200 µg/kg, discrete samples be composited into the same purge chamber. Once the con-
can be transferred to vessels containing an appropriate solvent, taminants are dissolved in the solvent, the concern of contami-
such as methanol. Because the solvent retains the volatiles in nant heterogeneity is decreased and the use of small sub-
solution, and only a small portion of the solvent is removed for samples of the extracts can be justified.
analysis, particle and contaminant unit size with respect to
6.1.8 Solid Sample for Non-Volatile Analysis—The method
subsample mass requirements can be considered.
of subsampling is dependent on the size of the allowable
particlesizeandthesizeofthecontaminantunit.Thefollowing
NOTE 2—Current analytical guidance recommends solvent extraction
subsections discuss different subsampling procedures that can
only for volatile organic concentrations at greater than 200 µg/kg.
be used as laboratory sample particle size and contaminant unit
However, solvent extraction may be used for solvents of lower concen-
tration levels if the solvent/solid ratio is reduced, or by using an analysis
vary in relationship to the allowable particle sizes listed in
system with lower detection limits.
Table 2. If the laboratory sample requires mixing prior to
subsampling, the methods in section 6.1.6 should be used.
6.1.4.3 The following subsections discuss different subsam-
pling procedures that can be used as particle size and contami-
6.1.9 Laboratory Sample Particle Size and Contaminant
nant unit vary in relationship to the allowable particle sizes
Unit Less Than the Allowable Particle Size:
listed in 6.1.1.
6.1.9.1 Transversal Subsampling (Rectangular Scoop) (see
6.1.5 Laboratory Sample Particle Size and Contaminant
Fig. 1)—One method of subsampling the materials is to use
Unit Less Than the Allowable Particle Size—Prepare sample
transversal subsampling (see Guide D6051). The entire labo-
vessel with the appropriate solvent and solvent volume as
ratory sample is emptied onto a non-contaminating smooth
specified in the method.Add the appropriate mass of sample to
surface. The sample is shaped into an elongated pile with a
the prepared vessel with a pre-cleaned coring total (see Guide
flattened top surface (1). Complete top-to-bottom transversal
D4547) or spatula as quickly as possible. The coring tool must
cuts are made across the pile and the extracted material is
be large enough to accommodate the largest sample matrix
transferred into a tared container. The transversal cuts are
particle. After volatile extraction, remove the appropriate
repeated until the appropriate mass is obtained. Cuts are made
volumeofthe
...