ASTM E2677-20
(Test Method)Standard Test Method for Estimating Limits of Detection in Trace Detectors for Explosives and Drugs of Interest
Standard Test Method for Estimating Limits of Detection in Trace Detectors for Explosives and Drugs of Interest
SIGNIFICANCE AND USE
5.1 Commercial trace detectors are used by first responders, security screeners, the military, and law enforcement to detect and identify explosive threats and drugs of interest quickly. These trace detectors typically operate by detecting chemical agents in residues and particles sampled from surfaces and can have detection limits for some compounds extending below 1 ng. A trace detector is set to alarm when its response to any target analyte exceeds a programmed threshold level for that analyte. Factory settings of such levels typically balance sensitivity and selectivity assuming standard operating and deployment conditions.
5.2 The LOD for a substance is commonly accepted as the smallest amount of that substance that can be reliably detected in a given type of medium by a specific measurement process (2). The analytical signal from this amount shall be high enough above ambient background variation to give statistical confidence that the signal is real. Methods for determining nominal LOD values are well known but pitfalls exist in specific applications. Vendors of trace detectors often report detection limits for only a single compound without defining the meaning of terms or reference to the method of determination.
Note 2: There are several different “detection limits” that can be determined for analytical procedures. These include the minimum detectable value, the instrument detection limit, the method detection limit, the limit of recognition, the limit of quantitation, and the minimum consistently detectable amount. Even when the same terminology is used, there can be differences in the LOD according to nuances in the definition used, the assumed response model, and the type of noise contributing to the measurement.
5.3 When deployed, the individual performance of a trace detector (for example, realistic LODs) is influenced by: (1) manufacturing differences, history, and maintenance; (2) operating configurations (for example, thermal desorption tem...
SCOPE
1.1 In harmony with the Joint Committee for Guides in Metrology (JCGM) and detection concepts of the International Union of Pure and Applied Chemistry (IUPAC) (1, 2)2, this test method uses a series of replicated measurements of an analyte at dosage levels giving instrumental responses that bracket the critical value, a truncated normal distribution model, and confidence bounds to establish a standard for estimating practical and statistically robust limits of detection.
Note 1: Other standards are available that evaluate the general performance of detection technologies for various analytes in complex matrices (for example, Practice E2520).
1.2 Here, the limit of detection (LOD90) for a compound is defined to be the lowest mass of that compound deposited on a sampling swab for which there is 90 % confidence that a single measurement in a particular trace detector will have a true detection probability of at least 90 % and a true nondetection probability of at least 90 % when measuring a process blank sample.
1.3 This particular test method was chosen on the basis of reliability, practicability, and comprehensiveness across tested trace detectors, analytes, and deployment conditions. The calculations involved in this test method are published elsewhere (3), and are performed through an interactive web-based calculator available on the National Institute of Standards and Technology (NIST) site: https://www-s.nist.gov/loda.
1.4 Intended Users—Trace detector developers and manufacturers, vendors, testing laboratories, and agencies responsible for public safety and enabling effective deterrents to terrorism.
1.5 While this test method may be applied to any detection technology that produces numerical output, the method is especially applicable to measurement systems influenced by heterogeneous error sources that lead to non-linear and heteroskedastic dose/response relationships and truncated or censored respons...
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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: E2677 − 20
Standard Test Method for
Estimating Limits of Detection in Trace Detectors for
1
Explosives and Drugs of Interest
This standard is issued under the fixed designation E2677; 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 heterogeneous error sources that lead to non-linear and het-
eroskedastic dose/response relationships and truncated or cen-
1.1 In harmony with the Joint Committee for Guides in
sored response distributions at low analyte levels. The proce-
Metrology (JCGM) and detection concepts of the International
2 dures have been tested using explosive and drug compounds in
UnionofPureandAppliedChemistry(IUPAC) (1, 2) ,thistest
trace detectors based on ion mobility spectrometry, gas
method uses a series of replicated measurements of an analyte
chromatography, and mass spectrometry (4). Compounds are
at dosage levels giving instrumental responses that bracket the
deposited as liquid solutions on swabs and dried before use.
critical value, a truncated normal distribution model, and
Background interferences introduced to the test samples were
confidence bounds to establish a standard for estimating
representative of a variety of conditions expected during
practical and statistically robust limits of detection.
deployment, but these conditions were not intended as com-
NOTE 1—Other standards are available that evaluate the general
prehensive in representing all possible scenarios. The user
performance of detection technologies for various analytes in complex
should be aware of the possibility that untested scenarios may
matrices (for example, Practice E2520).
lead to failure in the estimation of a reliable LOD90 value.
1.2 Here, the limit of detection (LOD90) for a compound is
1.6 Units—The values stated in SI units are to be regarded
defined to be the lowest mass of that compound deposited on
as the standard. No other units of measurement are included in
a sampling swab for which there is 90 % confidence that a
this standard.
single measurement in a particular trace detector will have a
1.7 This standard does not purport to address all of the
true detection probability of at least 90 % and a true nonde-
safety concerns, if any, associated with its use. It is the
tection probability of at least 90 % when measuring a process
responsibility of the user of this standard to establish appro-
blank sample.
priate safety, health, and environmental practices and deter-
1.3 This particular test method was chosen on the basis of
mine the applicability of regulatory limitations prior to use.
reliability, practicability, and comprehensiveness across tested
Some specific hazards statements are given in Section 8 on
trace detectors, analytes, and deployment conditions. The
Hazards.
calculations involved in this test method are published else-
1.8 This international standard was developed in accor-
where (3), and are performed through an interactive web-based
dance with internationally recognized principles on standard-
calculator available on the National Institute of Standards and
ization established in the Decision on Principles for the
Technology (NIST) site: https://www-s.nist.gov/loda.
Development of International Standards, Guides and Recom-
1.4 Intended Users—Trace detector developers and
mendations issued by the World Trade Organization Technical
manufacturers, vendors, testing laboratories, and agencies
Barriers to Trade (TBT) Committee.
responsible for public safety and enabling effective deterrents
to terrorism. 2. Referenced Documents
3
1.5 While this test method may be applied to any detection
2.1 ASTM Standards:
technology that produces numerical output, the method is E177 Practice for Use of the Terms Precision and Bias in
especially applicable to measurement systems influenced by
ASTM Test Methods
E200 Practice for Preparation, Standardization, and Storage
of Standard and Reagent Solutions for ChemicalAnalysis
1
This test method is under the jurisdiction of ASTM Committee E54 on
E288 Specification for Laboratory Glass Volumetric Flasks
Homeland Security Applications and is the direct responsibility of Subcommittee
E54.01 on CBRNE Sensors and Detectors.
Current edition approved Feb. 1, 2020. Published February 2020. Originally
3
approved in 2014. Last previous edition approved in 2014 as E2677 – 14. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/E2677-20. contact ASTM Customer S
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2677 − 14 E2677 − 20
Standard Test Method for
DeterminingEstimating Limits of Detection in Explosive
1
Trace Detectors for Explosives and Drugs of Interest
This standard is issued under the fixed designation E2677; 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
1.1 In harmony with the Joint Committee for Guides in Metrology (JCGM) and detection concepts of the International Union
2
of Pure and Applied Chemistry (IUPAC) (1, 2, 3) , this test method uses a series of replicated measurements of an analyte at dosage
levels giving instrumental responses that bracket the critical value, a truncated normal distribution model, and confidence bounds
to establish a standard for determiningestimating practical and statistically robust limits of detection to analytes sampled on swabs
by explosive trace detectors (ETDs).detection.
NOTE 1—Other standards are available that evaluate the general performance of detection technologies for various analytes in complex matrices (for
example, Practice E2520).
1.2 Here, the limit of detection (LOD90) for a compound is defined to be the lowest mass of a particular that compound
deposited on a sampling swab for which there is 90 % confidence that a single measurement in a particular ETD trace detector will
have a true detection probability of at least 90 % and a true nondetection probability of at least 90 % when measuring a process
blank sample.
1.3 This particular test method was chosen on the basis of reliability, practicability, and comprehensiveness across tested ETDs,
trace detectors, analytes, and deployment conditions. The calculations involved in this test method are published elsewhere (43),
and may be performed consistently with are performed through an interactive web-based toolcalculator available on the National
Institute of Standards and Technology (NIST) site: http://pubapps.nist.gov/loda.https://www-s.nist.gov/loda.
1.4 Intended Users—ETD developers, ETD vendors, ETD buyers, ETD testers, ETD users (first responders, security screeners,
and the military), and Trace detector developers and manufacturers, vendors, testing laboratories, and agencies responsible for
public safety and enabling effective deterrents to terrorism.
1.5 While this test method may be applied to any detection technology that produces numerical output, the method is especially
applicable to measurement systems influenced by heterogeneous error sources that lead to non-linear and heteroskedastic
dose/response relationships and truncated or censored response distributions at low analyte levels. The procedures have been
designed for ion mobility tested using explosive and drug compounds in trace detectors based on ion mobility spectrometry, gas
chromatography, and mass spectrometry (IMS)(4). based ETD systems and tested with low vapor pressure explosive compounds.
Compounds are deposited as liquid solutions on swabs and dried before use. As some swabs are absorbent, this deposition
procedure may not be optimal for those ETD technologies that rely on high coverage of analyte on the surface of the swab.
Background interferences introduced to the test samples were representative of a variety of conditions expected during deployment,
but these conditions were not intended as comprehensive in representing all possible scenarios. The user should be aware of the
possibility that untested scenarios may lead to failure in the determinationestimation of a reliable LOD90 value.
1.6 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this
standard.
1.7 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 8 on Hazards.
1
This test method is under the jurisdiction of ASTM Committee E54 on Homeland Security Applications and is the direct responsibility of Subcommittee E54.01 on
CBRNE Sensors and Detectors.
Current edition approved Feb. 1, 2014Feb. 1, 2020. Published February 2014February 2020. Originally approved in 2014. Last previous edition
...
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