ASTM D5788-95(2011)
(Guide)Standard Guide for Spiking Organics into Aqueous Samples
Standard Guide for Spiking Organics into Aqueous Samples
SIGNIFICANCE AND USE
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.
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.
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.
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. When environmental...
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, an...
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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
Designation: D5788 − 95 (Reapproved 2011)
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.Anumber 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 Theseproceduresapplyonlytoanalytesthataresoluble
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,thisgeneralapproachisgiventoserveasaguideline
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,dependingonwhichpartoftheanalyticalprocessis
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.
Laboratoryspikingteststhelaboratoryprocessonly.Spikingof
1.2 The procedures in this guide are focused on “matrix
sample extracts, concentrates, or dilutions will test only that
spike” preparation, analysis, results, and interpretation. The portion of the process subsequent to the addition of the spike.
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.Asample (the matrix) is fortified
(spiked) with the analyte of interest for a variety of analytical
1.7 This standard does not purport to address all of the
and quality control purposes. While the spiking of multiple
safety concerns, if any, associated with its use. It is the
sample test portions is discussed, the method of standard
responsibility of the user of this standard to establish appro-
additions is not covered.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.3 This guide is intended for use in conjunction with the
individual analytical test method that provides procedures for
2. Referenced Documents
analysis of the analyte or component of interest. The test
method is used to determine an analyte or component’s
2.1 ASTM Standards:
background level and, again after spiking, its now elevated
D1129Terminology Relating to Water
level. Each test method typically provides procedures not only
D1193Specification for Reagent Water
for samples, but also for calibration standards or analytical
D3694Practices for Preparation of Sample Containers and
control solutions, or both. These procedures include
for Preservation of Organic Constituents
preparation, handling, storage, preservation, and analysis tech-
D3856Guide for Management Systems in Laboratories
niques.Theseproceduresareapplicablebyextension,usingthe
Engaged in Analysis of Water
analyst’s judgement on a case-by-case basis, to spiking
D4375Practice for Basic Statistics in Committee D19 on
solutions, and are not reiterated in this guide. See also Practice
Water
E200 for preparation and storage information.
E200Practice for Preparation, Standardization, and Storage
of Standard and Reagent Solutions for ChemicalAnalysis
This guide is under the jurisdiction ofASTM 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 May 1, 2011. Published June 2011. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2005 as D5788–95 (2005). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D5788-95R11. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5788 − 95 (2011)
3. Terminology only.Spikingofsampleextracts,concentrates,ordilutionswill
be reflective of only that portion of the process subsequent to
3.1 Definitions—For definitions of terms used in this guide,
the addition of the spike.
refer to Terminology D1129.
5.4 Special precautions shall be observed when nonlabora-
3.2 Definitions of Terms Specific to This Standard:
tory personnel perform spiking in the field. It is recommended
3.2.1 matrix spike, n—the quantity (mass) of a component
thatallspikepreparationworkbeperformedinalaboratoryby
(analyte) of interest which is added to a sample (matrix) in
experienced analysts so that the field operation consists solely
order to test bias as measured by recovery (of that component
of adding a prepared spiking solution to the sample matrix.
under specific analytical conditions) and reported as percent
Training of field personnel and validation of their spiking
recovery (P).
techniques are necessary to ensure that spikes are added
3.2.2 spike, v—the addition of a known amount of an
accurately and reproducibly. Consistent and acceptable recov-
analyte of known identity to a measured volume of a sample
eries from duplicate field spikes can be used to document the
(from a specific matrix) to determine the efficiency with which
reproducibility of sampling and the spiking technique. When
the added analyte can be “recovered” from (measured in) that
environmentally labile compounds are used as spikes, the
matrix by the analytical system after exposure to a specific
spiking solution shall be protected up to the time of use by
portionofananalyticalprocess.Matrixspikingisaprocessfor
appropriate means such as chilling, protection from sunlight
accomplishing this. The precision and bias estimates from
and oxygen, or chemical preservation.
several trials under specific analytical conditions represent the
measurement efficiency with which the analyte may be deter-
NOTE1—Anyfieldspikedsample,ifknowntothelaboratory,shouldbe
labeledasafieldspikeinthefinalresultsreport.Also,wheneverpossible,
mined under these conditions.
field spiking of volatile compounds should be avoided.
3.2.3 spiking solution—the solution in which one or more
5.5 It is often tacitly assumed that the analyte component is
spikes are dissolved (along with any necessary preservatives).
recovered from the sample to approximately the same extent
This solution acts as a carrier to provide ease of measurement
that a spike of the same analyte is recovered from a spiked
and more rapid and thorough mixing of the spike into the
sample. One reason that this assumption may be incorrect is
sample, as compared to adding the spike as a pure compound.
thatthespikemaynotbeboundupinthesample(forexample,
4. Summary of Guide
with suspended matter) in the same way that the naturally
occurring analyte is bound in the sample. The spike may
4.1 This guide describes a technique for the addition of a
therefore be recovered from the sample differently than the
known amount of an organic analyte to an aqueous sample.
background level of the analyte. For this reason, as well as the
Instructions are given to help prevent loss of volatile analytes
fact that bias corrections can add variability, it is not good
in the sample headspace and to provide a homogeneous
practicetocorrectanalyticaldatausingspikerecoveries.Spike
solutionforsubsequentanalysis.Appropriateconcentrationsof
recovery information should, however, be reported along with
thespikerelativetotheoriginalconcentrationinthesampleare
the related sample analysis results.
discussed. Applications of the technique and aids in the
interpretation of results obtained are described.
5.6 This guide is also applicable to the preparation and use
ofspikesforquantificationbythemethodofstandardadditions
5. Significance and Use
and to the addition of surrogates and internal standards.
5.1 Matrix spiking of samples is commonly used to deter-
mine the bias under specific analytical conditions, or the
6. Apparatus
applicability of a test method to a particular sample matrix, by
6.1 StirringApparatus—Borosilicateglassbeads,4to6mm
determining the extent to which the added spike is recovered
in diameter, or small TFE-coated magnetic stirring bars. A
from the sample matrix under these conditions. Reactions or
small non-heating variable-speed magnetic stirrer is recom-
interactions of the analyte or component of interest with the
mended for use with the stirring bar.
sample matrix may cause a significant positive or negative
effect on recovery and may render the chosen analytical, or
6.2 Microsyringes—Standard gas chromatographic mi-
monitoring, process ineffectual for that sample matrix.
crosyringes of borosilicate glass with stainless steel needles,
suitableforinjectionofspikingsolutionsthroughaTFE-coated
5.2 Matrix spiking of samples can also be used to monitor
silicone septum. The TFE-tipped plungers may be contami-
the performance of a laboratory, individual instrument, or
nated by certain analytes. If this is determined to be likely, a
analystaspartofaregularqualityassuranceprogram.Changes
syringe may be dedicated to a single process, or a plain-tipped
inspikerecoveriesfromthesameorsimilarmatricesovertime
stainless steel plunger may be used to avoid cross-
mayindicatevariationsinthequalityofanalysesandanalytical
contamination. Sizes from 10 to 500 µL are appropriate,
results.
depending on the concentration and sample volumes used.
5.3 Spiking of samples may be performed in the field or in
thelaboratory,dependingonwhatpartoftheanalyticalprocess 6.3 Micropipettors—Stainless steel micropipettors with dis-
is to be tested. Field spiking tests the recovery of the overall posable glass tips are preferable to syringes for introduction of
process,includingpreservationandshippingofthesampleand spiking solutions into open sample containers, since they
may be considered a measure of the stability of the analytes in deliver more reproducibly and are less prone to cross-
the matrix. Laboratory spiking tests the laboratory process contamination. Sizes from 5 to 200 µL are appropriate.
D5788 − 95 (2011)
6.4 Syringes—Borosilicate glass syringes with demountable 7.4 Spiking Solutions—Spiking solutions of each analyte of
stainless steel needles may be used to measure volumes of interest are prepared individually or in combination, either
samples(spikedorunspiked)tobeinjectedintopurge-and-trap gravimetrically or volumetrically, correcting for density (for
sample introduction systems. liquid or solution standards). The preservation and storage
criteria found in the applicable analytical test method for its
6.5 Volumetric Transfer Pipets—Class A, used to deliver
calibration or check standards apply likewise to spiking solu-
knownvolumesofsampleandtoaddlargervolumesofspiking
tions.Thestabilityofastoredspikingsolutionshallbeverified
solutions.
routinely by the appropriate dilution of a portion of spiking
6.6 Volumetric Flasks—Class A volumetric flasks may be
solution to the laboratory’s analyte concentration of interest.
used to measure known volumes of sample.
Stability is demonstrated whenever the analyzed concentration
of a diluted spiking solution falls within the control limits for
6.7 Balance—An analytical (0.1-mg), semimicro (0.01-
mg), or micro (0.001-mg) balance. a routine laboratory control sample of the same concentration.
Where solubilities permit, stock spiking solutions are custom-
7. Reagents
arilyprepared25to1000timesasconcentratedastheworking
7.1 Purity of Reagents—At a minimum, reagent grade spiking solution, and are diluted volumetrically to produce the
working spiking solution at the time of use. In some cases,
chemicalsshallbeusedinallspikepreparations.Spectrograde,
high-pressure liquid chromatography (HPLC) grade, pesticide concentrated solutions may be stable at 4°C for substantially
longer periods than dilute solutions. Alternatively, prepare
grade, or ultrapure grade solvents shall be used to prepare
spikingsolutions.Reagentsofthehighestavailablepurityshall spike or spiking solution fresh for each batch of samples.
be used for spike analytes and demonstrated to be free of
8. Sampling
interfering substances for the subsequent test methods to be
performed. If possible, a primary standard grade shall be used. 8.1 Although sampling methodology is beyond the scope of
Unless otherwise indicated, it is intended that all reagents
this guide, a properly split or duplicate sample is of utmost
conform to the specifications of the Committee on Analytical importance to the successful measurement of spike recovery.
Reagents of the American Chemical Society. Other grades
This is especially critical in samples containing suspended
maybeused,provided(1)thatreagentpurityisunspecifiedand sediment or volatile analytes.
(2) that it is first ascertained that the reagent is of sufficiently
8.2 Sample containers shall be selected and prepared, and
high purity to permit its use without adversely affecting the
samplesshallbepreservedinaccordancewithPracticeD3694.
bias and precision of subsequent determinations. Purchased
spikingsolutionsshallbedemonstratedtobefreeofsubstances
9. Procedure
thatwouldinterferewithsubsequentanalysesbeingperformed,
9.1 Use relevant good laboratory practices in accordance
and the supplier’s stated concentration shall be verified by
with Guide D3856 and Practice E200.
analysis prior to use. Compensatory errors associated with
9.2 Nonvolatile Compounds—Except for volatile analytes,
self-referencingshouldbepreventedbyusingspikingsolutions
this category includes all analytes or components of interest.
of a standard originating from a source, when available,
Semi-volatile compounds, for which volatility is not a concern
different from that of the routine method calibration standa
...
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