ASTM D8332-20

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:D8332 −20
Standard Practice for
Collection of Water Samples with High, Medium, or Low
Suspended Solids for Identification and Quantification of
Microplastic Particles and Fibers
This standard is issued under the fixed designation D8332; 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 practice cannot replace education or experience and should be
usedinconjunctionwithprofessionaljudgment.Notallaspects
1.1 This practice provides for the collection of water
of this practice may be applicable in all circumstances. This
samples with high, medium, or low suspended solids to
practice is not intended to represent or replace the standard of
determine the presence, count, polymer type, and physical
care by which the adequacy of a given professional service
characteristics of microplastic particles and fibers. This collec-
must be judged, nor should this practice be applied without
tion practice has been validated for the collection of samples
consideration of a project’s many unique aspects.
from drinking water, surface waters, wastewater influent and
1.6 This standard does not purport to address all of the
effluent (secondary and tertiary), and marine waters. This
safety concerns, if any, associated with its use. It is the
practice is not limited to these particular water matrices;
responsibility of the user of this standard to establish appro-
however, the applicability of this practice to other aqueous
priate safety, health, and environmental practices and deter-
matrices must be demonstrated.
mine the applicability of regulatory limitations prior to use.
1.2 Water samples are passed through filters or sieves of
1.7 This international standard was developed in accor-
adequate mesh size to enable capture of the smallest desired
dance with internationally recognized principles on standard-
particle size. For waters with high or medium suspended solids
ization established in the Decision on Principles for the
content, a series of sieves with increasingly smaller mesh size
Development of International Standards, Guides and Recom-
should be used to prevent clogging and allow for the collection
mendations issued by the World Trade Organization Technical
of desired particle size fractions.
Barriers to Trade (TBT) Committee.
1.3 Subsequent sample preparation followed by analysis
utilizing either Pyrolysis gas chromatography/mass spectrom-
2. Referenced Documents
etry (Py-GC/MS), IR spectroscopy, or Raman spectroscopy 2
2.1 ASTM Standards:
may be used to identify the quantity (mass or number count)
D883 Terminology Relating to Plastics
and composition (polymer type) of microplastic particles/
D1193 Specification for Reagent Water
fibers. The spectroscopic methods can provide a count of the
number of particles and fibers present in a sample, and
3. Terminology
Py-GC/MS can provide the mass present in a sample. When
3.1 Definitions:
desired, microplastic particle/fiber size, shape and surface
3.1.1 For definitions of terms used in this standard, refer to
characteristics can be ascertained with appropriate instruments
Terminology D883.
such as a scanning electron microscope (SEM).
3.2 Definitions of Terms Specific to This Standard:
1.4 Units—The values stated in SI units are to be regarded
3.2.1 effluent, n—any stage of treated wastewater.
as the standard except where standard U.S. equipment is
3.2.2 influent, n—raw sewage entering a wastewater treat-
specified in imperial units, for example, inches and gallons. No
ment facility.
other units of measurement are included in this standard.
3.2.3 microplastic, n—any solid, synthetic organic poly-
1.5 Standard Practice—This practice offers a set of instruc-
meric material to which chemical additives or other substances
tions for performing one or more specific operations. This
may have been added, which are particles <5 mm in their
This practice is under the jurisdiction of ASTM Committee D19 on Water and
is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Organic Substances in Water. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved July 15, 2020. Published August 2020. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D8332-20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8332−20
largest dimension, and fibers no longer than 15 mm in length issues with heterogeneity of suspended solids and to reduce the
with an aspect ratio of at least 30:1 and <500 µm in its smallest standard error (the larger the sample size, the smaller the
dimension. standard error).
3.2.4 surface waters, n—a water body with its surface in
5.4 Microplastic particles/fibers retained on the sieves are
contact with the ambient atmosphere, examples which include
suitable for characterization in terms of size, shape, quantity,
lakes, rivers, and streams.
and composition (polymer type), dependent upon the chosen
analytical method.
3.2.5 suspended solids, n—refers to all matter which remain
in suspension in water media and that are removed by a 0.45
6. Equipment, Reagents, and Materials
µm filter.
6.1 References to purity of water – unless otherwise indi-
4. Summary of Practice
cated–shallbeunderstoodtomeanreagentwaterasdefinedby
4.1 This practice is suitable for sampling of most water Type IV of Specification D1193.
qualities from low to high suspended solids content dependent
6.2 A 5-gal metal container to hold the assembled sieve
upon project goals. It consists of processing water samples
stack with either (1) a spigot valve at the bottom and
through filters or sieves of adequate mesh size to enable
non-plastic spacers to raise the sieves above the bottom
capture of the smallest desired particle or fiber size. For waters
surface, or (2) a series of 20 at ⁄8 in. holes drilled through the
with high to medium suspended solids content, a series of
bottom, allowing the processed water to flow through unim-
sieves with increasingly smaller mesh size should be used to
peded.
prevent clogging and allow for the collection of desired
6.3 Stainless steel tubing for use in conveying the flow of
particle/fiber size fractions.
sample water from the pump (non-pressurized system) or
4.2 All particulates less than 5 mm in the largest dimension
sampling tap/spigot (pressurized system) to the sieve stack.
and fibers less than 15 mm in length should be retained for
6.4 Several 4 in. glass petri dishes.
preparation and analysis.
6.5 High Suspended Solids Water Samples — Wastewater
4.3 Water flowing through the sieves must be metered to
record the total volume, to enable calculations of “numbers of Influent (Fig. 1):
particles/fibers per unit volume” or “mass per unit volume.”
6.5.1 Stainless steel submersible pumpcapableofdelivering
The flow rate of water with high suspended solids across the approximately1.0galperminutewhenpulling24-hourdiurnal
sieves must be observed and appropriately regulated to avoid
wastewater influent samples from a non-pressurized system.
blinding (obstruction) of the sieve perforations. Flow volume
6.5.2 Aseries of 8 in. diameter stainless steel stacked sieves
must be throttled-back and recorded when blinding occurs.
with the suggested following mesh sizes: 20 µm, 50 µm, 150
µm, 300 µm, 500 µm, 1000 µm, and 5000 µm.
4.4 Wastewater influent (high suspended solids) sampling
6.5.3 Flow control valve (or in-line flow meter if water
should include 24 consecutive hours of flow collection to
quality conditions permit) capable of achieving a nominal
ensure capture of peak diurnal flow concentrations.
flowrate of 1.0 gal per minute, accurate enough to measure an
approximate filtered volume within 65%,or 672 gal out of
5. Significance and Use
1440 gal (approximately 5450 L) total per 24 hours.
5.1 When significant quantities of inorganic or organic
6.5.4 Digital outdoor timer.
material are present in water samples (high suspended solids),
microplastic particles/fibers can be masked and the ability to 6.6 Low to Medium Suspended Solids Water Samples —
conduct reliable identification and quantification analyses of Surface Water and Secondary-Treated Wastewater Effluent
the plastic particles/fibers can be impeded.
(Fig. 1 or Fig. 2):
6.6.1 Stainless steel submersible pump capable of pulling
5.2 In order to quantify the occurrence of microplastic
samples from a non-pressurized system or ambient surface
particles/fibers in wastewater influent (high suspended solids),
water as needed, to enable delivery of 1500 L (approximately
thesamplingproceduremustbeabletoreliablycollectsamples
400 gal). With a pressurized system/line, a sampling tap or
at a constant flow over the desired 24-hour interval to reflect
spigot is required to pull the sample.
changes in diurnal flow. For wastewater influent the capture
6.6.2 Flow control valve or in-line flow meter accurate
flow rate should be no less than 1 GPM over the 24-hour
enough to measure an approximate filtered volume within 65
interval (approximately 1440 gal or 5450 L total) to minimize
% for 1500 L.
the problem with heterogeneity of the suspended solids and to
6.6.3 A series of stacked stainless-steel sieves with the
reduce the standard error (the larger the sample size, the
suggested following mesh sizes: 20 µm, 150 µm, 500 µm, and
...