ASTM D5788-95(2024)

Standard Guide for Spiking Organics into Aqueous Samples

SIGNIFICANCE AND USE
5.1 Matrix spiking of samples is commonly used to determine the bias under specific analytical conditions, or the applicability of a test method to a particular sample matrix, by determining the extent to which the added spike is recovered from the sample matrix under these conditions. Reactions or interactions of the analyte or component of interest with the sample matrix may cause a significant positive or negative effect on recovery and may render the chosen analytical, or monitoring, process ineffectual for that sample matrix.  
5.2 Matrix spiking of samples can also be used to monitor the performance of a laboratory, individual instrument, or analyst as part of a regular quality assurance program. Changes in spike recoveries from the same or similar matrices over time may indicate variations in the quality of analyses and analytical results.  
5.3 Spiking of samples may be performed in the field or in the laboratory, depending on what part of the analytical process is to be tested. Field spiking tests the recovery of the overall process, including preservation and shipping of the sample and may be considered a measure of the stability of the analytes in the matrix. Laboratory spiking tests the laboratory process only. Spiking of sample extracts, concentrates, or dilutions will be reflective of only that portion of the process subsequent to the addition of the spike.  
5.4 Special precautions shall be observed when nonlaboratory personnel perform spiking in the field. It is recommended that all spike preparation work be performed in a laboratory by experienced analysts so that the field operation consists solely of adding a prepared spiking solution to the sample matrix. Training of field personnel and validation of their spiking techniques are necessary to ensure that spikes are added accurately and reproducibly. Consistent and acceptable recoveries from duplicate field spikes can be used to document the reproducibility of sampling and the spiking technique....
SCOPE
1.1 This guide covers the general technique of “spiking” aqueous samples with organic analytes or components. It is intended to be applicable to a broad range of organic materials in aqueous media. Although the specific details and handling procedures required for all types of compounds are not described, this general approach is given to serve as a guideline to the analyst in accurately preparing spiked samples for subsequent analysis or comparison. Guidance is also provided to aid the analyst in calculating recoveries and interpreting results. It is the responsibility of the analyst to determine whether the methods and materials cited here are compatible with the analytes of interest.  
1.2 The procedures in this guide are focused on “matrix spike” preparation, analysis, results, and interpretation. The applicability of these procedures to the preparation of calibration standards, calibration check standards, laboratory control standards, reference materials, and other quality control materials by spiking is incidental. A sample (the matrix) is fortified (spiked) with the analyte of interest for a variety of analytical and quality control purposes. While the spiking of multiple sample test portions is discussed, the method of standard additions is not covered.  
1.3 This guide is intended for use in conjunction with the individual analytical test method that provides procedures for analysis of the analyte or component of interest. The test method is used to determine an analyte or component's background level and, again after spiking, its now elevated level. Each test method typically provides procedures not only for samples, but also for calibration standards or analytical control solutions, or both. These procedures include preparation, handling, storage, preservation, and analysis techniques. These procedures are applicable by extension, using the analyst's judgement on a case-by-case basis, to spiking solutions, ...

General Information

• Status: Published
• Publication Date: 31-Mar-2024
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: D19 - Water
• Drafting Committee: D19.06 - Methods for Analysis for Organic Substances in Water

Relations

• Replaces: ASTM D5788-95(2017) - Standard Guide for Spiking Organics into Aqueous Samples
• Effective Date: 01-Apr-2024
• Referred By: ASTM D4193-08(2020)e1 - Standard Test Method for Thiocyanate in Water
• Effective Date: 01-Apr-2024
• Referred By: ASTM D2036-09(2022) - Standard Test Methods for Cyanides in Water
• Effective Date: 01-Apr-2024
• Referred By: ASTM D4282-15(2022) - Standard Test Method for Determination of Free Cyanide in Water and Wastewater by Microdiffusion
• Effective Date: 01-Apr-2024
• Referred By: ASTM D2330-20 - Standard Test Method for Methylene Blue Active Substances
• Effective Date: 01-Apr-2024

Overview

ASTM D5788-95(2024): Standard Guide for Spiking Organics into Aqueous Samples provides comprehensive guidance for the technique of spiking aqueous samples with organic analytes. Developed by ASTM International, this standard is globally recognized and helps laboratories and field personnel accurately evaluate the recovery, bias, and overall performance of analytical test methods involving organic materials in water-based matrices.

Matrix spiking is integral for assessing method accuracy and the influence of sample matrices on analyte recovery. Applications of this guide contribute to quality assurance across diverse environmental and industrial laboratory settings, supporting regulatory compliance and consistent analytical results.

Key Topics

• Purpose of Matrix Spiking: Matrix spiking is a critical tool to determine method bias, test method suitability, and recoveries under specific laboratory or field conditions. It highlights any positive or negative matrix effects that may influence analyte recovery.

• Quality Assurance in Laboratories: Routine spiking supports laboratory quality assurance by enabling performance monitoring of instruments and analysts. Monitoring spike recoveries over time can reveal trends or deviations in method performance.

• Field and Laboratory Spiking: The guide distinguishes between field spiking (testing the full process, including preservation, transport, and storage of analytes) and laboratory spiking (assessing stability and recovery during laboratory procedures only).

• Analytical Method Compatibility: Analysts are responsible for ensuring that sample matrices, analytes, and test methods are compatible, maintaining data integrity.

• Calculation and Interpretation of Recoveries: The guide outlines steps for calculating spike recoveries, interpreting percent recoveries, and understanding the impact of spike-to-background ratios.

• Precautions and Training: Special attention is advised if spiking is performed by non-laboratory personnel in the field. Training and validation of field techniques are necessary to guarantee accurate, reproducible results.

Applications

• Environmental Monitoring: Spiking is widely employed to validate water testing protocols for environmental compliance, such as in drinking water, wastewater, and natural water body analyses.

• Analytical Method Validation: Laboratories use matrix spikes to verify that analytical methods provide accurate results in various aqueous matrices, including complex or challenging samples.

• Laboratory Quality Control: Regular use of spiked samples acts as an internal check, ensuring instrument and analyst performance stays within acceptable limits.

• Process and Regulatory Compliance: Industrial and municipal water treatment facilities apply matrix spiking to demonstrate adherence to regulatory standards and to troubleshoot system performance.

• Training and Field Operations: Field technicians can employ pre-prepared spiking solutions to assess sample preservation, shipping, and handling, ensuring sample integrity from collection to analysis.

Related Standards

The effective use of ASTM D5788-95(2024) often involves integration with additional ASTM standards supporting water analysis and laboratory quality:

• ASTM D1129: Terminology Relating to Water
• ASTM D1193: Specification for Reagent Water
• ASTM D3694: Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• ASTM D3856: Guide for Management Systems in Laboratories
• ASTM E200: Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions

Referencing these related documents ensures comprehensive quality assurance and methodological consistency for spiking and water sample analysis.

Keywords: matrix spike, organics in water, aqueous sample analysis, spiking solution, analyte recovery, laboratory quality assurance, environmental compliance, ASTM D5788, water testing standards, analytical method validation.

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: D5788 − 95 (Reapproved 2024)
Standard Guide for
Spiking Organics into Aqueous Samples
This standard is issued under the fixed designation D5788; 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 1.4 These procedures apply only to analytes that are soluble
in water at the concentration of the spike plus any background
1.1 This guide covers the general technique of “spiking”
material, or to analytes soluble in a solvent that is itself
aqueous samples with organic analytes or components. It is
water-soluble. The system used in the later case must result in
intended to be applicable to a broad range of organic materials
a homogeneous solution of analyte and sample. Meaningful
in aqueous media. Although the specific details and handling
recovery data cannot be obtained if an aqueous solution or
procedures required for all types of compounds are not
homogeneous suspension of the analyte of interest in the
described, this general approach is given to serve as a guideline
sample cannot be attained.
to the analyst in accurately preparing spiked samples for
subsequent analysis or comparison. Guidance is also provided 1.5 Matrix spiking may be performed in the field or in the
to aid the analyst in calculating recoveries and interpreting
laboratory, depending on which part of the analytical process is
results. It is the responsibility of the analyst to determine to be tested. Field spiking tests the recovery of the overall
whether the methods and materials cited here are compatible
process, including preservation and shipping of the sample.
with the analytes of interest. Laboratory spiking tests the laboratory process only. Spiking of
sample extracts, concentrates, or dilutions will test only that
1.2 The procedures in this guide are focused on “matrix
portion of the process subsequent to the addition of the spike.
spike” preparation, analysis, results, and interpretation. The
applicability of these procedures to the preparation of calibra-
1.6 The values stated in SI units are to be regarded as
tion standards, calibration check standards, laboratory control
standard. No other units of measurement are included in this
standards, reference materials, and other quality control mate-
standard.
rials by spiking is incidental. A sample (the matrix) is fortified
1.7 This standard does not purport to address all of the
(spiked) with the analyte of interest for a variety of analytical
safety concerns, if any, associated with its use. It is the
and quality control purposes. While the spiking of multiple
responsibility of the user of this standard to establish appro-
sample test portions is discussed, the method of standard
priate safety, health, and environmental practices and deter-
additions is not covered.
mine the applicability of regulatory limitations prior to use.
1.3 This guide is intended for use in conjunction with the
1.8 This international standard was developed in accor-
individual analytical test method that provides procedures for
dance with internationally recognized principles on standard-
analysis of the analyte or component of interest. The test
ization established in the Decision on Principles for the
method is used to determine an analyte or component’s
Development of International Standards, Guides and Recom-
background level and, again after spiking, its now elevated
mendations issued by the World Trade Organization Technical
level. Each test method typically provides procedures not only
Barriers to Trade (TBT) Committee.
for samples, but also for calibration standards or analytical
control solutions, or both. These procedures include
2. Referenced Documents
preparation, handling, storage, preservation, and analysis tech-
2.1 ASTM Standards:
niques. These procedures are applicable by extension, using the
D1129 Terminology Relating to Water
analyst’s judgement on a case-by-case basis, to spiking
D1193 Specification for Reagent Water
solutions, and are not reiterated in this guide. See also Practice
D3694 Practices for Preparation of Sample Containers and
E200 for preparation and storage information.
for Preservation of Organic Constituents
D3856 Guide for Management Systems in Laboratories
This guide is under the jurisdiction of ASTM Committee D19 on Water and is
the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2024. Published April 2024. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2017 as D5788 – 95 (2017). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D5788-95R24. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5788 − 95 (2024)
Engaged in Analysis of Water (Withdrawn 2024) analyst as part of a regular quality assurance program. Changes
D4375 Practice for Basic Statistics in Committee D19 on in spike recoveries from the same or similar matrices over time
Water (Withdrawn 2018) may indicate variations in the quality of analyses and analytical
E200 Practice for Preparation, Standardization, and Storage results.
of Standard and Reagent Solutions for Chemical Analysis
5.3 Spiking of samples may be performed in the field or in
the laboratory, depending on what part of the analytical process
3. Terminology
is to be tested. Field spiking tests the recovery of the overall
3.1 Definitions:
process, including preservation and shipping of the sample and
3.1.1 For definitions of terms used in this standard, refer to
may be considered a measure of the stability of the analytes in
Terminology D1129.
the matrix. Laboratory spiking tests the laboratory process
only. Spiking of sample extracts, concentrates, or dilutions will
3.2 Definitions of Terms Specific to This Standard:
be reflective of only that portion of the process subsequent to
3.2.1 matrix spike, n—the quantity (mass) of a component
the addition of the spike.
(analyte) of interest which is added to a sample (matrix) in
order to test bias as measured by recovery (of that component
5.4 Special precautions shall be observed when nonlabora-
under specific analytical conditions) and reported as percent
tory personnel perform spiking in the field. It is recommended
recovery (P).
that all spike preparation work be performed in a laboratory by
3.2.2 spike, v—the addition of a known amount of an experienced analysts so that the field operation consists solely
of adding a prepared spiking solution to the sample matrix.
analyte of known identity to a measured volume of a sample
(from a specific matrix) to determine the efficiency with which Training of field personnel and validation of their spiking
techniques are necessary to ensure that spikes are added
the added analyte can be “recovered” from (measured in) that
matrix by the analytical system after exposure to a specific accurately and reproducibly. Consistent and acceptable recov-
portion of an analytical process; matrix spiking is a process for eries from duplicate field spikes can be used to document the
accomplishing this; the precision and bias estimates from reproducibility of sampling and the spiking technique. When
several trials under specific analytical conditions represent the environmentally labile compounds are used as spikes, the
measurement efficiency with which the analyte may be deter- spiking solution shall be protected up to the time of use by
mined under these conditions. appropriate means such as chilling, protection from sunlight
and oxygen, or chemical preservation.
3.2.3 spiking solution, n—the solution in which one or more
spikes are dissolved (along with any necessary preservatives);
NOTE 1—Any field spiked sample, if known to the laboratory, should be
this solution acts as a carrier to provide ease of measurement labeled as a field spike in the final results report. Also, whenever possible,
field spiking of volatile compounds should be avoided.
and more rapid and thorough mixing of the spike into the
sample, as compared to adding the spike as a pure compound.
5.5 It is often tacitly assumed that the analyte component is
recovered from the sample to approximately the same extent
4. Summary of Guide
that a spike of the same analyte is recovered from a spiked
4.1 This guide describes a technique for the addition of a sample. One reason that this assumption may be incorrect is
that the spike may not be bound up in the sample (for example,
known amount of an organic analyte to an aqueous sample.
Instructions are given to help prevent loss of volatile analytes with suspended matter) in the same way that the naturally
occurring analyte is bound in the sample. The spike may
in the sample headspace and to provide a homogeneous
solution for subsequent analysis. Appropriate concentrations of therefore be recovered from the sample differently than the
background level of the analyte. For this reason, as well as the
the spike relative to the original concentration in the sample are
discussed. Applications of the technique and aids in the fact that bias corrections can add variability, it is not good
practice to correct analytical data using spike recoveries. Spike
interpretation of results obtained are described.
recovery information should, however, be reported along with
5. Significance and Use
the related sample analysis results.
5.1 Matrix spiking of samples is commonly used to deter-
5.6 This guide is also applicable to the preparation and use
mine the bias under specific analytical conditions, or the
of spikes for quantification by the method of standard additions
applicability of a test method to a particular sample matrix, by
and to the addition of surrogates and internal standards.
determining the extent to which the added spike is recovered
from the sample matrix under these conditions. Reactions or 6. Apparatus
interactions of the analyte or component of interest with the
6.1 Stirring Apparatus—Borosilicate glass beads, 4 mm to
sample matrix may cause a significant positive or negative
6 mm in diameter, or small TFE-coated magnetic stirring bars.
effect on recovery and may render the chosen analytical, or
A small non-heating variable-speed magnetic stirrer is recom-
monitoring, process ineffectual for that sample matrix.
mended for use with the stirring bar.
5.2 Matrix spiking of samples can also be used to monitor
6.2 Microsyringes—Standard gas chromatographic mi-
the performance of a laboratory, individual instrument, or
crosyringes of borosilicate glass with stainless steel needles,
suitable for injection of spiking solutions through a TFE-coated
silicone septum. The TFE-tipped plungers may be contami-
The last approved version of this historical standard is referenced on
www.astm.org. nated by certain analytes. If this is determined to be likely, a
D5788 − 95 (2024)
syringe may be dedicated to a single process, or a plain-tipped ences to water shall be understood to mean reagent water
stainless steel plunger may be used to avoid cross- conforming to Type I of Specification D1193 and demonstrated
contamination. Sizes from 10 μL to 500 μL are appropriate, to be free of interfering substances for the test(s) being
depending on the concentration and sample volumes used. performed.
6.3 Micropipettors—Stainless steel micropipettors with dis- 7.3 Methanol—Spectrograde, HPLC grade, or ultrapure
posable glass tips are preferable to syringes for introduction of grade methanol is preferable for use as a solvent for water-
spiking solutions into open sample containers, since they insoluble analytes in most trace-level analyses. Other water-
deliver more reproducibly and are less prone to cross- soluble solvents may be useful for certain analytes. Solvents
contamination. Sizes from 5 μL to 200 μL are appropriate. shall be checked before use for interfering substances by
analysis.
6.4 Syringes—Borosilicate glass syringes with demountable
stainless steel needles may be used to measure volumes of 7.4 Spiking Solutions—Spiking solutions of each analyte of
samples (spiked or unspiked) to be injected into purge-and-trap interest are prepared individually or in combination, either
sample introduction systems. gravimetrically or volumetrically, correcting for density (for
liquid or solution standards). The preservation and storage
6.5 Volumetric Transfer Pipets—Class A, used to deliver
criteria found in the applicable analytical test method for its
known volumes of sample and to add larger volumes of spiking
calibration or check standards apply likewise to spiking solu-
solutions.
tions. The stability of a stored spiking solution shall be verified
6.6 Volumetric Flasks—Class A volumetric flasks may be
routinely by the appropriate dilution of a portion of spiking
used to measure known volumes of sample.
solution to the laboratory’s analyte concentration of interest.
Stability is demonstrated whenever the analyzed concentration
6.7 Balance—An analytical (0.1 mg), semimicro (0.01 mg),
or micro (0.001 mg) balance. of a diluted spiking solution falls within the control limits for
a routine laboratory control sample of the same concentration.
7. Reagents
Where solubilities permit, stock spiking solutions are custom-
arily prepared 25 to 1000 times as concentrated as the working
7.1 Purity of Reagents—At a minimum, reagent grade
spiking solution, and are diluted volumetrically to produce the
chemicals shall be used in all spike preparations. Spectrograde,
working spiking solution at the time of use. In some cases,
high-pressure liquid chromatography (HPLC) grade, pesticide
concentrated solutions may be stable at 4 °C for substantially
grade, or ultrapure grade solvents shall be used to prepare
longer periods than dilute solutions. Alternatively, prepare
spiking solutions. Reagents of the highest available purity shall
spike or spiking solution fresh for each batch of samples.
be used for spike analytes and demonstrated to be free of
interfering substances for the subsequent test methods to be
8. Sampling
performed. If possible, a primary standard grade shall be used.
Unless otherwise indicated, it is intended that all reagents
8.1 Although sampling methodology is beyond the scope of
conform to the specifications of the Committee on Analytical this guide, a properly split or duplicate sample is of utmost
Reagents of the American Chemical Society. Other grades
importance to the successful measurement of spike recovery.
may be used, provided (1) that reagent purity is unspecified and This is especially critical in samples containing suspended
(2) that it is first ascertained that the reagent is of sufficiently
sediment or volatile analytes.
high purity to permit its use without adversely affecting the
8.2 Sample containers shall be selected and prepared, and
bias and precision of subsequent determinations. Purchased
samples shall be preserved in accordance with Practices
spiking solutions shall be demonstrated to be free of substances
D3694.
that would interfere with subsequent analyses being performed,
and the supplier’s stated concentration shall be verified by
9. Procedure
analysis prior to use. Compensatory errors associated with
9.1 Use relevant good laboratory practices in accordance
self-referencing should be prevented by using spiking solutions
with Guide D3856 and Practice E200.
of a standard originating from a source, when available,
different from that of the routine method calibration standards. 9.2 Nonvolatile Compounds—Except for volatile analytes,
this category includes all analytes or components of interest.
7.2 Purity of Water—Unless otherwise indicated, references
Semi-volatile compounds, for which volatility is not a concern
to water shall be understood to mean reagent water as defined
for these spiking procedures, are included in this classification.
by the individual test method to be used to analyze a sample
9.2.1 Analyze one portion of the sample for the analyte(s) of
after spiking. If more than one test method is to be utilized, the
interest. Duplicate analyses are recommended to determine the
minimum criteria of each test method must be met. If test
overall precision of the sample splitting and analysis process. If
method reagent water specifications are not available, refer-
this is not possible, estimate the concentrations of analytes of
interest, based upon knowledge of the sample source.
9.2.2 Use the result of this analysis or estimation to deter-
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
mine the appropriate amount of spike to be added to the
DC. For suggestions on the testing of reagents not listed by the American Chemical
sample.
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
9.2.2.1 To be of maximum value for quantification of the
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD. analyte(s) or for the evaluation of method accuracy, the
D5788 − 95 (2024)
concentration in the spiked sample should be at least double, 9.2.8 Examine the spiked sample for any increased turbid-
but ideally not over five times, the concentration of the analyte ity. If turbidity persists after extensive mixing, it may be
in the unspiked sample, as long as the total analyte concentra- necessary to respike a new portion of sample using a lower
tion can be brought within the test method’s dynamic range. concentration of analyte, a smaller volume of more concen-
Spike concentrations below this range lead to highly variable
trated spiking solution, or a new spiking solution prepared in a
spike recoveries, as described in Section 11. Higher spike more miscible solvent.
concentrations may mask the effect that real interferences, such
9.3 Volatile Analytes:
as matrix effects, are having on the analyte at its background
9.3.1 Analyze one portion of the sample for the analyte(s) of
levels, leading to over-optimistic estimates of analyte recovery.
interest. Duplicate analyses are recommended to determine the
9.2.2.2 If the spiked analyte is not necessarily present in the
overall precision of the sample splitting (see Section 6) and
sample, but is added only to validate the general recovery of an
analysis process. If this is not possible, estimate the concen-
analytical method or technique, then adjust the concentration
tration of the analytes of interest, based on knowledge of the
after spiking to two to five times the “action level,” the analyte
sample source.
concentration of primary interest to the data user, for example,
9.3.2 Use the result of this analysis or estimation to deter-
the detection limit or the regulatory limit for an environmental
mine the appropriate amount of spike to be added to the
sample, or at a critical set point or process optimization point
sample.
for a process sample. Otherwise, adjust the spike to two to five
times the anticipated concentration of the samples, or
...