ASTM D6517-00(2012)e1
(Guide)Standard Guide for Field Preservation of Groundwater Samples
Standard Guide for Field Preservation of Groundwater Samples
SIGNIFICANCE AND USE
4.1 Groundwater samples are subject to chemical, physical, and biological change relative to in- situ conditions at the ground surfaces as a result of exposure to ambient conditions during sample collection (for example, pressure, temperature, ultraviolet radiation, atmospheric oxygen, and contaminants) (1) (2).5 Physical and chemical preservation of samples minimize further changes in sample chemistry that can occur from the moment the groundwater sample is retrieved, to the time it is removed from the sample container for extraction or analysis, or both. Measures also must be taken to preserve the physical integrity of the sample container.
4.2 The need for sample preservation for specific analytes should be defined prior to the sampling event and documented in the site-specific sampling and analysis plan in accordance with Guide D5903. The decision to preserve a sample should be made on a parameter-specific basis as defined by individual analytical methods.
SCOPE
1.1 This guide covers methods for field preservation of groundwater samples. Laboratory preservation methods are not described in this guide.
1.2 This standard may involve hazardous materials, operations, and equipment. 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.
1.3 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word“ Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
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Designation: D6517 − 00 (Reapproved 2012)
Standard Guide for
Field Preservation of Groundwater Samples
This standard is issued under the fixed designation D6517; 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.
ε NOTE—Editorial changes were made throughout in May 2012.
1. Scope 2.2 Other Documents:
Standard Methods for the Examination of Water and
1.1 This guide covers methods for field preservation of
Wastewater, 20th ed., 1999
groundwatersamples.Laboratorypreservationmethodsarenot
International Air Transport Association Dangerous Goods
described in this guide.
Regulations
1.2 This standard may involve hazardous materials,
U.S. EPA, Office of Solid Waste, SW-846, 3rd ed.
operations, and equipment. This standard does not purport to
U.S. EPA, Title 40, Code of Federal Regulations, Part 136
address all of the safety concerns, if any, associated with its
U.S. DOT, Title 49, Code of Federal Regulations, Part 172
use. It is the responsibility of the user of this standard to
establish appropriate safety and health practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions—For definitions of common technical terms
1.3 This guide offers an organized collection of information
in this standard, refer to Terminology D653.
or a series of options and does not recommend a specific
3.2 Definitions of Terms Specific to This Standard:
course of action. This document cannot replace education or
3.2.1 chemicalpreservation—theadditionofacidic,alkaline
experienceandshouldbeusedinconjunctionwithprofessional
or biologically toxic compounds, or combination thereof, to a
judgment. Not all aspects of this guide may be applicable in all
groundwater sample to prevent changes in chemical properties
circumstances. This ASTM standard is not intended to repre-
of the sample that may occur after collection.
sent or replace the standard of care by which the adequacy of
a given professional service must be judged, nor should this
3.2.2 holding time—the maximum amount of time that may
document be applied without consideration of a project’s many
transpire from the moment a sample container is filled to the
unique aspects. The word“ Standard” in the title of this
time the sample is extracted or analyzed. Holding times are
document means only that the document has been approved
parameter-specific, variable in length, and defined by labora-
through the ASTM consensus process.
tory analytical methods.
3.2.3 physical preservation—methods that are implemented
2. Referenced Documents
to protect the physical integrity of a groundwater sample from
2.1 ASTM Standards:
the time the sample is collected until the sample is analyzed.
D653 Terminology Relating to Soil, Rock, and Contained
3.2.4 temperature blank—a quality control sample that is
Fluids
transported with samples and is used by the laboratory per-
D3694 Practices for Preparation of Sample Containers and
forming sample analyses to verify that temperature-sensitive
for Preservation of Organic Constituents
samples have been adequately cooled to 4°C for shipment to
D5903 Guide for Planning and Preparing for a Groundwater
and arrival at the laboratory (see Note 1).
Sampling Event
D6089 Guide for Documenting a Groundwater Sampling
NOTE1—Formsoftemperatureblankinclude:(1)usingacommercially
Event prepared, fluid-filled bottle containing a permanently fixed National
InstituteofStandardsandTechnology(NIST)-certified(orNIST-traceable)
thermometer, the temperature of which is read directly by the laboratory;
ThisguideisunderthejurisdictionofASTMCommitteeD18onSoilandRock
(2) submission of a designated sample container filled with water (for
and is the direct responsibility of Subcommittee D18.21 on Groundwater and
example, groundwater, distilled water, or deionized water) that is opened
Vadose Zone Investigations
Current edition approved May 15, 2012. Published December 2012. Originally
approved in 2000. Last previous edition approved in 2005 as D6517 – 00 (2005).
DOI: 10.1520/D6517-00R12E01. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D6517 − 00 (2012)
by the laboratory and immediately measured for temperature of the water
on container design, including shape, volume, gas tightness,
using a National Institute of Standards and Technology-certified (or
materials of construction, and use of cap liners, are defined for
NIST-traceable) thermometer; or (3) submission of a designated container
specificparametersorsuitesofparameters(forexample,amber
filled with water (for example, groundwater, distilled water, or deionized
glasscontainersprotectphotosensitiveanalytessuchas(PCBs)
water) on which the laboratory uses a remote infrared temperature sensor
to measure the temperature. Regardless of the method used, all measured from chemical alteration). Specifications for sample container
temperatures are compared against the required temperature for each
selection are documented in parameter-specific analytical
sample (for example, 4°C) in conjunction with a previously defined
methods (for example, ASTM, U.S. EPA SW846, AWWA
window of acceptable variance from this required temperature as docu-
Standard Methods) as well as in Federal (40 CFR Part 136),
mented in the sampling and analysis plan.
state, and local regulatory guidelines on groundwater sample
4. Significance and Use collection and preservation. The type of sample containers to
be used in a sampling event should be determined during
4.1 Groundwater samples are subject to chemical, physical,
sampling event planning in accordance with Guide D5903 and
and biological change relative to in- situ conditions at the
documented in the sampling and analysis plan as described in
ground surfaces as a result of exposure to ambient conditions
8.1 of this guide and Guide D6089.
during sample collection (for example, pressure, temperature,
ultraviolet radiation, atmospheric oxygen, and contaminants) 6.1.1.2 SampleContainerPackingandShipping—Fieldper-
(1)(2). Physical and chemical preservation of samples mini- sonnelshouldpackageandshipsamplesincompliancewithall
mize further changes in sample chemistry that can occur from applicable regulations including the Department of Transpor-
the moment the groundwater sample is retrieved, to the time it tation (for example, Title 49 Code of Federal Regulations, Part
is removed from the sample container for extraction or
172) and the International Air Transportation Association
analysis, or both. Measures also must be taken to preserve the (IATA). Sample containers should be shipped in a manner that
physical integrity of the sample container.
will ensure the samples are received intact by the laboratory, at
the appropriate temperature, and as soon as possible to allow
4.2 The need for sample preservation for specific analytes
sufficient time for the laboratory to perform the requested
should be defined prior to the sampling event and documented
analyses within the holding time defined by the applicable
in the site-specific sampling and analysis plan in accordance
laboratory analytical method for each parameter.
with Guide D5903. The decision to preserve a sample should
be made on a parameter-specific basis as defined by individual 6.1.1.3 Temperature Control—Samples analyzed for some
analytical methods. parameters (for example, nitrite) require temperature control.
The temperature of these samples should be lowered to 4°C
5. Timing and Purpose of Groundwater Sample
immediately after performing any field analyses required (for
Preservation
example, temperature or pH) and chemical preservation (3).
When necessary, temperature should be lowered as soon as
5.1 Groundwater samples should be preserved in the field at
possible and maintained at 4°C until the sample is analyzed.
the time of sample collection using physical means to prevent
Sample temperatures can be lowered most efficiently using
sample container breakage or temperature increases, and
on-site refrigeration or wet ice. Wet ice may need to be
chemical means to minimize changes in groundwater sample
replenished prior to shipping to maintain sample temperatures
chemistry prior to laboratory analysis.
at 4°C. If required by regulation, dry ice may be used to cool
6. Groundwater Sample Preservation Procedures
samples, however, care should be taken to prevent sample
freezing. Reuseable ice packs may be used to lower sample
6.1 Groundwater sample preservation procedures are
temperature, however, they often do not have the capacity to
grouped into two general categories: (1) physical preservation
adequately lower or maintain temperatures, or both;
and (2) chemical preservation. Preservation procedures should
consequently, their use is not recommended (4).Atemperature
address the following details on a parameter-specific basis:
blank should be used with each shipping container of samples
sample container design and construction, protection from
to determine actual sample temperatures at the time the sample
ultraviolet light, temperature control, chemical addition, and
shipment is received by the laboratory.
pH control measures (2).
6.1.1 Physical Preservation of Groundwater Samples—
6.1.2 Chemical Preservation of Groundwater Samples:
Physical groundwater sample preservation methods include:
6.1.2.1 Chemical preservation of groundwater samples in-
(1) use of appropriate sample collection containers for each
volves the addition of one or more chemicals (reagent-grade or
parameter being analyzed, (2) use of appropriate packing of
better)onaparameter-specificbasistoprotectsampleintegrity.
sample containers for shipment to prevent sample container
Appendix X1 provides examples of common analyte-specific
breakage and potential cross-contamination of samples during
chemical preservation methods.
shipment, and (3) temperature control.
6.1.2.2 Chemical preservation is specified in numerous
6.1.1.1 Sample Container Selection —Proper selection of
analytical methods as well as in various regulatory guidance
containers for groundwater sample collection is an important
documents. Chemicals can be used to adjust sample pH or
means of protecting the integrity of the sample. Specifications
inhibit microbial activity to prevent chemical alteration of
samples. Initial pH of samples should be determined prior to
5 chemical preservation so appropriate chemical adjustment can
The boldface numbers in parentheses refer to the list of references at the end of
this standard. be made.
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D6517 − 00 (2012)
ing high concentrations of calcium carbonate may effervesce when
6.1.2.3 Groundwater samples can be chemically preserved
acidified. In these cases, modifications of sample preservation methods
inoneofseveralways:(1)titrationofpH-adjustingcompounds
may be necessary, such as collecting an unpreserved sample or using
(for example, nitric acid) while monitoring pH change with a
alternate chemical preservatives.Any modifications must be pre-approved
pH meter or narrow-range litmus paper; (2) addition of a
by regulatory agencies and laboratories involved, and allowed by the
premeasured volume of liquid preservative (for example,
sampling and analysis plan.
NOTE 8—It may be necessary to establish site-specific protocol to
sulfuric acid) contained in glass vials or ampules to the sample
address acceptable periods for storage and storage conditions for prepre-
container (Note 2); (3) addition of pelletized preservative (for
served sample containers due to the potential for chemical reactions to
example, sodium hydroxide) to the sample container; and (4)
occur between the chemical preservative and the empty sample container.
addition of preservative to empty sample containers prior to
8. Report
shipment of the empty containers to the field (that is, prepre-
servedsamplecontainers)Note3.Afterthesamplecontaineris
8.1 Records should be kept for all forms of sample preser-
filled and preserved, it should be securely capped and gently
vation used for groundwater samples. Report the following in
inverted to ensure uniform distribution of the preservative
accordance with Guide D6089:
throughout the sample (seeNote 4).
8.1.1 Type of sample container(s) used for each parameter
being analyzed (volume, materials of construction, type of cap,
NOTE 2—Care should be taken not to add too large a volume of
chemical preservative to prevent sample dilution. A generally accepted and so forth);
limit is 0.5 % maximum dilution.
8.1.2 Number of each type of sample container actually
NOTE 3—The use of prepreserved containers should be evaluated on a
filled;
parameter-specific basis.
8.1.3 Packaging method(s) used to prevent sample bottle
NOTE 4—Pelletized preservatives may take longer to dissolve and mix
breakage during sample storage and shipment;
with the sample.
8.1.4 Temperature and pH of groundwater samples at the
6.1.2.4 The end point of chemical preservation, designed to
time of sample collection;
adjust pH to specific final pH levels, (for example, <2.0 or
8.1.5 How groundwater samples were cooled to 4°C, if
>12.0)shouldbeverifiedinthefieldusingnarrow-rangelitmus
required for physical preservation;
paper (pH paper) or a properly calibrated pH meter. A small
8.1.6 Sample temperature at the time of sample shipment;
amount of sample can either be decanted into a separate
8.1.7 Chemical preservative(s) used on a parameter-specific
container or a parallel sample can be collected for pH verifi-
basis:
cation(for example, for samples containing light non-aqueous
8.1.7.1 What chemicals were added, by whom, time, and
phases), rather than introducing foreign materials into the
date,
sample container being submitted for analysis. When collect-
8.1.7.2 Specifications (if known) on actual preservative(s)
ing samples in prepreserved containers, care must be taken not
used (that is, source, manufacturer, grade, lot number, and so
to prerinse the container with the sample and to avoid
forth),
overfilling the con
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