ASTM D6323-98
(Guide)Standard Guide for Laboratory Subsampling of Media Related to Waste Management Activities
Standard Guide for Laboratory Subsampling of Media Related to Waste Management Activities
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 the 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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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Designation: D 6323 – 98
Standard Guide for
Laboratory Subsampling of Media Related to Waste
Management Activities
This standard is issued under the fixed designation D 6323; 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 uids, With or Without Solids, in Drums or Similar Con-
tainers
1.1 This guide covers common techniques for obtaining
D 5792 Practice for Generation of Environmental Data
representative subsamples from a sample received at a labora-
Related to Waste Management Activities: Development of
tory for analysis. These samples may include solids, sludges,
Data Quality Objectives
liquids, or multilayered liquids (with or without solids).
D 5956 Guide for Sampling Strategies for Hetergeneous
1.2 The procedures and techniques discussed in this guide
Wastes
depend upon the sample matrix, the type of sample preparation
D 6051 Guide for Composite Sampling and Field Subsam-
and analysis performed, the characteristic(s) of interest, and the
pling for Environmental Waste Management Activities
project specific instructions or data quality objectives.
1.3 This guide includes several sample homogenization
3. Terminology
techniques, including mixing and grinding, as well as informa-
3.1 contaminant unit, n—the largest particle size that con-
tion on how to obtain a specimen or split laboratory samples.
tains the contaminant of interest
1.4 This guide does not apply to air or gas sampling.
3.1.1 Discussion—The contaminant of concern, as defined
1.5 The values stated in SI units are to be regarded as the
by the project objectives, may be associated with all the
standard.
particle sizes or associated with only a certain particle size or
1.6 This standard does not purport to address all of the
sizes. At the time of waste generation, discharge or spill, the
safety concerns, if any, associated with its use. It is the
particle size of this contaminant of concern may be on the
responsibility of the user of this standard to establish appro-
atomic or molecular scale, such as solvent spill into sand, or a
priate safety and health practices and determine the applica-
macro scale, such as lead acid batteries at a dump site. The
bility of regulatory limitations prior to use.
contaminant unit may also be in-between these scales, such as
2. Referenced Documents lead particles encapsulated in coal. In practice, the contaminant
unit may change if the contaminant unit becomes absorbed or
2.1 ASTM Standards:
adsorbed to particles larger than the contaminant unit. It is the
C 702 Practice for Reducing Samples of Aggregate to
size of the contaminant unit at the time of subsampling, not at
Testing Size
the time of generation, that is referred to as the contaminant
C 859 Terminology Relating to Nuclear Materials
unit.
D 346 Practice for the Collection and Preparation of Coke
3.2 maximum allowable particle size, n—the largest lineal
Samples for Laboratory Analysis
dimension of a sample’s individual particles accepted for a
D 2234 Test Methods for Collection of a Gross Sample of
given sample mass.
Coal
3.2.1 Discussion—The maximum allowable particle size is
D 4547 Guide for Sampling Waste and Soils for Volatile
sometimes referred to as the allowable particle size. A simple
Organic Compounds
method of measurement is a sieve.
D 4823 Guide for Core Sampling Submerged Unconsoli-
3.3 multilayered sample, n—a sample consisting of two or
dated Sediments
more clearly differentiated components.
D 5743 Practice for Sampling Single or Multilayered Liq-
3.3.1 Discussion—Multilayered samples are those with two
or more distinct visual layers of material. These layers may be
the result of differences in density, such as liquid/liquid layers
This guide is under the jurisdiction of ASTM Committee D34 on Waste (for example, chlorinated solvents and water, water and oil),
Management and is the direct responsibility of Subcommittee D34.01.01 on
liquid/solid layers (for example, sludge), solid/solid layers (for
Planning for Sampling.
example, small rocks and large rocks), or combinations of
Current edition approved Sept. 10, 1998. Published December 1998.
these layers (for example water, oil, and soil). These layers
Annual Book of ASTM Standards, Vol 04.02.
Annual Book of ASTM Standards, Vol 12.01.
Annual Book of ASTM Standards, Vol 05.05.
Annual Book of ASTM Standards, Vol 11.02.
Annual Book of ASTM Standards, Vol 11.04.
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.
D 6323
may also be the result of depositional layering, such as green discussed and clarified prior to initiating any subsampling
clay and silty sand from a coring sample. procedure. These instructions may include such options as
3.4 particle size, n—the controlling lineal dimension of those found in Table 1. The limitations and advantages of these
individual particles (see Terminology C 859). methods are also found in this table. The data user should be
3.5 representative subsample, n—a subsample collected in informed about the limitations and advantages of all subsam-
such a manner that it reflects one or more characteristics of pling procedures prior to deciding which one to use.
interest (as defined by the project objectives) of the laboratory
5.1.2 If the data user still provides no instructions upon
sample from which it was collected.
being contacted, laboratory personnel should explain to the
3.5.1 Discussion—A representative subsample can apply to
data user that the laboratory’s standard operating procedures,
a single sample, or a composite sample.
which reflect the concerns and issues discussed in this stan-
3.6 sample, n—a portion of material taken from a larger
dard, will be used. The sample should be treated as if the scale
quantity for the purpose of estimating properties or composi-
of the contamination is on the micro level, and no artifacts can
tion of the larger quantity, (see Guide D 6051).
be removed. Since sample matrices and types and mechanisms
3.7 sludge, n—Any mixture of solids that settles out of
of contamination are infinitely variable and require judgments
solution. Sludges contain liquids that are not apparent as free
to be made, it is advisable that experienced analysts decide
liquids, (see Practice D 5743).
which subsampling techniques be employed. These procedures
3.8 subsample, n—a portion of a sample taken for the
must be discussed and clarified with the data user prior to
purpose of estimating properties or composition of the whole
initiating any subsampling procedure.
sample, (see Guide D 6051).
5.2 If the sample integrity or composition is not as antici-
3.8.1 Discussion—A subsample is also commonly referred
pated, the data user must be contacted to confirm or clarify the
to by such terms as specimen, aliquot, subsample, or analytical
instructions. An example of when this would be necessary
subsample. To avoid confusion, the term specimen is used to
would be a case where a coring sleeve was received at the
refer to the final portion of the sample used during analysis.
laboratory. On opening the container, the analyst notices clay in
The material received at the laboratory will be referred to as the
one end of the sleeve, and sand at the other end. Before the
laboratory sample. All portions subsampled in-between receipt
analyst can proceed, the appropriate instructions from the data
at the laboratory and the specimen are referred to as sub-
user must be obtained.
samples. The subsample may be the specimen.
5.2.1 Field samples should be collected in appropriate
containers for the analyses requested. If the submitted sample
4. Significance and Use
is improperly collected, the data user should be contacted by
4.1 This guide discusses options for taking a subsample
laboratory personnel. If the data user authorizes the laboratory
from a sample submitted to a laboratory. If followed, it will
to continue with the analysis, a note should be made in the
minimize the bias and variance of the characteristic of interest
receival documentation, and also in the case narrative in the
of the laboratory sample prior to analysis.
final report.
4.2 The guide will describe appropriate instructions to be
5.3 Documentation during the subsampling process is criti-
submitted to the laboratory with the field sample.
cal. Since subsampling techniques may bias the results, the
4.3 This guide is intended for use in the laboratory to take a
subsampling method used must be noted in the analytical
representative subsample or specimen of the whole field
logbook.
sample for direct analysis or sample preparation for analysis. It
5.3.1 Anytime the analytical result will be biased, it must be
is intended for field personnel, data users, laboratory sample
documented, and the data user should be notified prior to
reception personnel, analysts, and managers.
beginning any subsampling technique. For example, if head-
4.4 To obtain a representative subsample, layer analysis,
space exists in a container arriving at the laboratory, some
grinding, mixing, and changing the physical state such as
volatile components will have partitioned into that headspace.
digesting, drying, melting or freezing may be required. This
However, if the data user decides to proceed with the analysis,
guide considers cone and quartering, riffle splitting, and
the analytical logbook and the case narrative on the final report
particle size reduction.
should indicate this condition.
5. General Considerations
5.4 Particle size is the physical dimension of an object’s
5.1 Successful implementation of this standard depends on pieces or parts. The maximum particle size contained within a
effective communication between the data user and the labo- laboratory sample is the largest of these pieces. The contami-
nant of concern, as defined by the project objectives, may be
ratory staff. The selection of optimal subsampling procedures,
techniques, and strategy by the laboratory depends on the associated with all particle sizes or associated with only a
intended use of the data. The data user should submit appro- certain particle size or sizes. The largest of these particle sizes,
priate instructions with all samples and, when necessary, the that contain the contaminant of interest, would be the contami-
laboratory staff should contact the data user for confirmation or nant unit. The contaminant unit, at the time of waste genera-
further clarification of these instructions. tion, discharge or spill, may be on the atomic or molecular
5.1.1 The appropriate instructions must be reviewed by both scale, such as a solvent spill into sand, or a macro scale, such
the laboratory receiving personnel and the analyst(s) or super- as lead acid batteries at a dump site. The contaminant unit may
visor. If there are no instructions, the appropriate laboratory also be in-between these scales, such as lead particles encap-
personnel should contact the data user. Options should be sulated in coal. In practice, the contaminant unit may change if
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.
D 6323
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.
cone and quarter, grind, riffle, sieve) information.
A
May be
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