January 2000 Volume 2 Number
1
27th
Annual Symposium on Crime Laboratory Development
Abstracts of Presentations
Las Vegas, Nevada
September 13-17, 1999
Author List
Mishalanie,
E. A., Consulting
Analytical Chemist, Enigma Analytical,
Breckenridge, Colorado:
Validating Analytical Chemistry Methods: A Means to Defensible
Data
Richardson,
C. F., Project
Officer, U. S. Drug Enforcement Administration, Arlington, Virginia:
The National Forensic Laboratory Information System (NFLIS)
St.
Clair, J. J., Columbus
Police Crime Laboratory, Columbus, Ohio, and Fisher, B. A. J., Los
Angeles County Sheriff's Office Crime Laboratory, Los Angeles,
California: Forensic Science Legislative Initiatives
Title List
Forensic
Science Legislative Initiatives by St. Clair, J. J., Columbus
Police Crime Laboratory, Columbus, Ohio, and Fisher, B.
A. J., Los Angeles County Sheriff's Office Crime Laboratory,
Los Angeles, California
The
National Forensic Laboratory Information System (NFLIS) by Richardson,
C. F., Project Officer, U. S. Drug Enforcement Administration,
Arlington, Virginia
Validating
Analytical Chemistry Methods: A Means to Defensible Data by Mishalanie,
E. A., Consulting Analytical Chemist, Enigma Analytical,
Breckenridge, Colorado
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The following
abstracts of the presentations are ordered alphabetically by
authors' last names.
Validating
Analytical Chemistry Methods:
A Means to Defensible Data
E. A. Mishalanie
Consulting Analytical
Chemist
Enigma Analytical
Breckenridge, Colorado
Introduction
Analytical chemistry plays
a major role in forensic laboratories. Techniques from the field
of analytical chemistry are used to examine diverse forms of
physical evidence such as glass, soil, drugs, ink, paint, body
fluids, tissue, explosives, and petroleum products. The successful
application of analytical chemistry methods in forensic laboratories
requires highly skilled and creative examiners. In addition,
the test results must be highly defensible and of known quality.
To achieve these objectives, the analytical methods used during
examinations need some form of validation.
This article is intended
to provide practical information for forensic laboratory directors,
managers, and supervisors to assist with the implementation of
appropriate and efficient method validation programs. It contains
a review of common terms from measurement science, a general
description of the components of method validation studies, and
suggestions for implementing a method validation program within
a forensic laboratory.
Measurement Process Components
Chemical analysis is one
important step in a measurement process. However, a complete
measurement process consists of four phases: planning, sampling,
chemical analysis, and decision making. Proper planning is critical.
This phase involves defining why the measurements are needed,
how the data will be used, which parameters need to be estimated,
how sampling and chemical analysis will be conducted, and at
what level errors can be tolerated in the final results. The
second phase requires the use of proper sampling design and sampling
procedures to obtain test portions (subsamples) that are representative
of a population under investigation (i.e., all physical evidence
of interest). During some forensic investigations, an entire
population may be collected, whereas other investigations require
sampling at the crime scene. In either case, the laboratory usually
has to subsample the evidence prior to chemical analysis. Therefore,
sampling and subsampling steps are involved in most measurement
process. The third step in the measurement process involves chemical
analysis. If representative samples and subsamples are obtained,
and if the error in the analytical methods is known, then reliable
test results can be obtained for the fourth step: defensible
decision making based on the forensic laboratory data.
Qualitative and Quantitative
Analyses
Chemical analyses can be
designed to obtain qualitative data and quantitative data. The
goal of qualitative analysis is to identify one or more chemicals
that may be present in a sample. The goal of quantitative analysis
is to determine how much of a particular chemical is present.
Although qualitative analyses are generally performed for identification
purposes, there are also situations where quantitative data characteristics
may be important. For example, a reliable identification cannot
be made unless there is a minimum amount of a chemical present
in a sample. Therefore, any qualitative analysis method has a
minimum identifiable amount associated with it, which is a quantitative
characteristic. Qualitative analyses are also performed to compare
the chemical composition of two or more different samples to
determine if they are similar. If a comparison requires knowledge
of the amounts present in addition to the types of chemicals
present, then the comparative qualitative methods also have quantitative
characteristics that need to be investigated by the laboratory.
Therefore, chemical analysts in forensic laboratories using methods
for qualitative analyses may need to be concerned with several
quantitative analysis issues, also.
A more complex analytical
chemistry problem is created by a need for quantitative data
in addition to qualitative data. Laboratory analysts need to
have a best estimate of how close the quantitative, numerical
values are to the true values. Obviously, the true values are
not known. However, a variety of method validation studies and
quality control practices allow chemical analysts in laboratories
to obtain information about potential sources of measurement
error. Without this information, a reported numerical value is
difficult to interpret and may be very misleading.
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The Meaning of Accuracy
Most measurements are estimates.
Two types of measurement errors affect these estimates: bias
and variability. It should be noted that the word error
does not mean mistake when used in the context of measurement
science. Bias is a systematic offset from a true but unknown
value. For quantitative analysis, a bias results in either an
underestimate or overestimate of the amount of a chemical present
in a sample. For qualitative analysis, a positive bias may result
in the identification of a chemical that is not really present.
This results in a false-positive decision error. A negative bias
may result in failure to identify a chemical that is truly present.
This results in a false-negative decision error. Variability,
typically called precision, results in scattered data when measurements
are repeated. Too much variability in a measurement process yields
inconclusive and potentially misleading data. On the other hand,
data sets with minimal variability (high precision) do not guarantee
accuracy. If potential sources of bias are not known, a precise
data set may be precisely wrong.
It is common for laboratory
customers to ask how accurate the measurements are. This is a
difficult question to answer because the accuracy of a final
result is affected by numerous sources of bias and variability
from both sampling and chemical analysis. Accuracy is difficult
to assess and impossible to prove. To prove accuracy, a true
value must be known to compare to an estimated value; however,
if a true value is known, then there is no need to make measurements!
Despite this apparent dilemma,
there are ways to minimize and assess measurement inaccuracy.
Laboratories attempt to estimate the inaccuracy of their analyses
by performing method validation studies and by using a variety
of quality control (QC) samples. If the studies and QC approaches
are not properly designed, these estimates of inaccuracy can
be unrealistic and may not include sources of bias and variability
from sampling. It is a difficult fact to accept, but the true
accuracy of any measurement is something that can never be known.
The only option is to provide a best estimate, which is why the
quality of the sampling and analytical measurement designs is
extremely important.
Analytical Methods
Analytical methods are documented
procedural steps used by the examiner to obtain the final test
results. Methods are designed for specific chemicals, contained
in specific matrices, and at defined concentration levels. Analytical
methods are also designed to answer specific questions. Complete,
concise documentation is necessary to reconstruct, justify, and
defend the scientific approach used by the laboratory. Methods
should not be viewed as stagnant, recipe-like documents. There
are a variety of formats for analytical methods, and the format
should be customized for use in a particular laboratory on the
basis of the expertise of the forensic scientists, the flow of
the work through the laboratory, and the nature of the analyses
performed by the laboratory. If analytical methods are not being
followed by the examiners, then there is usually a problem in
one or more of the following areas:
- The method is poorly written,
- The method is outdated and
needs to be updated, or
- The examiners do not understand
the scientific principles underlying the test procedures.
Although it is usually desirable
for methods to be followed as written, there are some procedures
within methods that routinely require modification or optimization
on the basis of scientific judgment. Such nonrigid procedures
within methods should be clearly identified so that the examiner
legitimately can make the necessary modifications. The modifications
should be thoroughly documented on bench sheets or in notebooks
so that the scientific approach can be reconstructed and defended.
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Analytical Method Validation
The term analytical method
validation has a variety of meanings to scientists from different
disciplines. In the most general sense, this term refers to the
process of determining and demonstrating that test results produced
by a given method are useful for an intended purpose. Method
validation efforts provide knowledge of the performance characteristics
of methodology. This knowledge renders the data defensible, creates
confidence in the reliability of the test methods, and leads
to correct decisions. If the performance characteristics of a
method are not known, then it is not possible to interpret properly
and use the test results in accordance with currently accepted
scientific standards for data quality.
There are a variety of method-performance
characteristics that can be assessed, such as selectivity, quantitation
range, detection limit, bias, precision, and the ruggedness of
a method. There are many ways to study each of these performance
characteristics, and some of the characteristics may not be important
for certain types of examinations. Thus, designing a method validation
approach is not a black-and-white issue, and forensic laboratories
have unique application areas when compared with other types
of laboratories. This makes the concept of method validation
appear to be confusing and difficult. In actuality, the most
difficult task is to appropriately define the measurement goals
and criteria for acceptable test method performance. If the results
are to be useful for an intended purpose, then the first step
is to describe the purpose (i.e., the questions that need to
be answered) and exactly what useful means. When these
goals are defined, the important method-performance characteristics
become obvious, and laboratory personnel can efficiently generate
meaningful method validation data.
Method Validation Scenarios
There are three general scenarios
for the validation of analytical chemistry methods:
- validation of new methods
for routine examinations;
- validation of methods currently
in use; and
- validation of methods used
during short-term, unique examinations.
Each scenario is described
separately, although the technical considerations for each are
similar.
Validating New Methods
for Routine Use
Some forensic examinations
may be considered routine. The term routine does not imply that
the methods are simple or easy to perform; rather, it means that
the laboratory regularly conducts these types of examinations
and that the test methods are standardized, methodical, predictable,
and customary. When new analytical chemistry methods are to be
implemented for routine use, proper planning is possible and
a formal and detailed method validation study is highly beneficial.
A thorough method validation study prior to method implementation
significantly improves the operational efficiency of the laboratory
and provides the foundation for producing well-characterized,
highly defensible data.
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Validating Currently Used
Routine Methods
In many laboratories,
there are methods that have been in use for several years. Formal
method validation studies may not have been conducted, yet the
laboratories feel confident enough to report data to their customers.
In some cases, this confidence may be justifiable. However, reporting
data without determining the important performance characteristics
of the methods is a very dangerous practice. There are ways to
validate methods that have been in use for a long period of time.
In the meantime, it is not necessary to stop using the methods
unless performance problems are revealed by an inspection of
historical data or new validation data.
The first area to address
is the current state of the method documentation. If the method
is poorly documented, then this problem needs to be rectified
immediately. Next, any QC data acquired during the period of
method use should be collected and critically analyzed. On the
basis of an assessment of the nature and quantity of the QC data,
the laboratory may need to perform additional method validation
studies to study performance characteristics that were not adequately
addressed by the historical data. In addition to QC data, proficiency
test results may be used to assess method performance during
the time period of interest. However, caution must be exercised
when using proficiency testing results for method validation
purposes. The proficiency testing programs must be properly designed
and trustworthy. For example, proficiency test samples for chemical
analysis should be of known composition and heterogeneity should
be minimized. This is not always the case, however, because chemical
characterization is expensive and many test sponsors do not conduct
sufficient studies to provide laboratories with trustworthy reference
materials for method validation purposes.
After reviewing QC data and
perhaps performing additional validation studies, method validation
reports should be prepared for currently used methods. This will
provide evidence that the critical performance characteristics
have been addressed and that the capabilities of the methods
are known and defensible.
Another situation that arises
with currently used routine methods is determining the need for
revalidation. This may be necessary when the scope of the method
is expanded beyond its originally defined boundaries. For example,
changes in chemical levels (concentration or mass), sample matrices,
or substantial changes in procedural steps may necessitate revalidation
of the methods. The need for revalidation and the extent of the
study are professional judgment calls. A revalidation study may
involve only a few performance characteristics, and an original
validation report may be amended to include new validation data.
Validating Methods Used
During Short-Term, Unique Examinations
This scenario may
account for numerous situations in forensic laboratories. The
forensic scientist is faced with an analytical problem that is
not routine, and he or she must produce usable, defensible data
in a short period of time. Can methods used under these conditions
be considered valid or validated? Consider two definitions of
the term method validation:
- Method validation is generating
evidence to support claims of method capabilities as applied
under a specific set of laboratory conditions.
- Method validation is proof
that a laboratory, implementing a particular method, is able
to generate useful data for an intended purpose.
Although many scientists
perceive method validation studies as lengthy processes (as they
often are for routine methods), the fundamental definitions of
the term do not necessarily imply that this has to be the case.
It is possible to validate methods used during short-term, unique
examinations. The main differences between the validation of
unique methods and routine methods are
- the scientific approach
implemented to explore the method-performance characteristics,
- the time frame of the studies,
and
- the nature of the documentation
of the methods and the studies.
Methods used during short-term,
unique examinations are usually narrowly focused and are extremely
thorough within that narrow scope. The use of multiple methods
or analytical techniques is usually required, and some of the
techniques may be highly complex. These scientific approaches
are typically not acceptable for routine analyses because of
the cost or complexity. Unique examinations require a high level
of expertise and creativity. The documentation of the methods
and the validation data are usually found in a laboratory notebook
rather than in a formal report. The key is to have reconstructable
and defensible data and information. If the relevant performance
characteristics of the methods are addressed and the data are
useful for the intended purpose, then the methods are indeed
validated.
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Method Validation Topics
There are nine general topic
areas to consider for method validation studies. It may not be
necessary to address all of the nine areas. The method validation
study design depends on the laboratory's qualitative and quantitative
data requirements, and it also depends on the validation scenario
as described previously. The topic areas are
- method scope,
- selectivity,
- calibration,
- bias,
- precision or variability,
- sensitivity,
- quantitation range,
- detection limit, and
- ruggedness.
It should be noted that the
terminology associated with method validation study components
is not standardized. The descriptions provided in the following
sections are based on general analytical principles and are not
derived from any one particular approach recommended in the scientific
literature.
Method Scope
There should always
be a description of the method scope included in a method. The
scope describes the boundaries for the valid application of the
method. It includes a description of the chemicals intended for
measurement, the sample matrices accommodated, and the appropriate
concentration range or levels of the chemical(s) intended for
measurement. The scope should also include a statement about
the purpose of the method, plus a description of any known limitations
or assumptions. The scope should be derived from an assessment
of the needs of the laboratory customer and the intended use
of the data. The benefits associated with determining and describing
the scope of a method are to assist with method validation study
design and to safeguard against misinterpretation or misuse of
the laboratory's data.
Selectivity
Selectivity refers to the ability of an analytical
method to correctly identify a chemical of interest in the presence
of other chemicals contained in a sample. Specificity
is a related term, and it refers to the ability to identify a
specific form of a chemical such as a specific oxidation state
or isomer. Selectivity is important for both qualitative and
quantitative analytical methods. The benefits of studying method
selectivity are to minimize the potential for misidentifying
chemicals (false-positive decision errors) and to identify sources
of bias in quantitative methods.
Calibration
This is sometimes referred to as linear range or working range.
Calibration is a procedure in a method that establishes instrument
or sensor response. It is usually accomplished by using high-quality
reference materials of known composition. The calibration step
in a method is critical because the calibration data provide
a reference for the qualitative identification of chemicals and
for all quantitative calculations. Instrument response characteristics
need to be studied and documented to justify and defend the identity
and quantity of the chemicals measured. In addition, a thorough
study of the instrument calibration performance characteristics
allows for efficient calibration designs for routine method applications.
This can lead to substantial savings in time and other resources.
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Bias
An overall bias in a measurement process causes the truth or
true value to be consistently missed. There are numerous potential
sources of bias; they are additive; they can occur in either
a positive or negative direction from a true value; and they
can arise during sampling, subsampling, and chemical analysis.
Method validation studies should include an assessment of analytical
measurement bias, which is a performance characteristic of a
method. Whenever possible, bias from sampling, subsampling, or
both should also be studied because these steps in the measurement
process also contribute, sometimes substantially, to overall
bias in the final analytical result. Substantial biases in a
measurement process produce inaccurate data.
Precision
Precision is a general term describing the
closeness of agreement among measured values when measurements
are repeated. It is a performance characteristic that actually
reflects measurement variability. Precision may be assessed in
several ways, and the study designs depend on the sources of
variability that a laboratory wishes to investigate and understand.
Terms such as repeatability and reproducibility
are used to describe the precision of analytical methods when
sampling variability is minimized (i.e., test materials are made
as homogeneous as possible). The total precision associated with
a final test result is also dependent on variability introduced
by sampling and subsampling.
Because analytical measurements
are not exact and no material is perfectly homogeneous, there
will always be variability in test results when measurements
are repeated. Most laboratories estimate the precision of the
analytical measurement step only. Although this information is
necessary and extremely useful, sampling or subsampling studies
should be conducted whenever possible to understand sources of
variability from these steps in a measurement process.
Upon completion of properly
designed bias and precision studies, it should be possible to
estimate method inaccuracy. When sampling and subsampling contributions
to bias and precision are studied, the inaccuracy of the entire
measurement process can be estimated, and this is also true for
the total uncertainty associated with a test result. It is necessary
to study both bias and precision performance characteristics
because both of these affect the overall accuracy of a final
test result.
Sensitivity
Method sensitivity refers to the ability of a method,
performed under prescribed conditions, to discriminate between
samples containing different amounts of a chemical. This concept
is important when quantitative data are used to compare two or
more samples to determine if their chemical compositions are
similar. The sensitivity of the method is dependent on the calibration,
bias, and precision performance characteristics. If the margin
of error from the analytical measurement step is large, then
the method sensitivity may be inadequate for a particular comparison.
Poor method sensitivity may result in inconclusive or misleading
test results. A sensitive method enables the examiner to detect
a small difference between the average amount of a chemical in
different samples. However, the practical significance of any
observed difference always needs to be considered, and sample
heterogeneity must be taken into account.
A related concept is instrument
sensitivity. This generally refers to the performance capabilities
of the instrumental analysis step in a method. Instrument sensitivity
is derived from data collected during calibration studies. The
term sensitivity is also used in the context of detection limit
discussions. This is different from method sensitivity, and it
usually refers to the detection capabilities of instrument detectors.
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Quantitation Range
The quantitation range reflects the lower and upper concentration
or mass limits that can be quantitatively measured by a method.
However, one generally accepted definition of the term quantitative
does not exist. Some scientists believe that any time a number
is reported from an analysis, then quantitative data have been
provided.
Another common definition
of quantitative involves only the precision characteristics of
a method. It is probably best to define the lower and upper limits
of a method's quantitation range on the basis of the actual range
of chemical concentrations studied during method validation.
When this commonsense approach is used, data are available to
characterize bias and precision at and between the limits. In
this context, the term quantitative means that the laboratory
is willing to report numerical values within the stated quantitation
range and that the data are of known quality in terms of analytical
bias and precision.
Detection Limit
A detection limit refers to the smallest amount of a chemical
that can be identified and reported as being present with an
associated level of confidence. There are numerous specific definitions
of this term and numerous approaches for estimating this limit.
This performance characteristic is usually associated with trace
and ultra-trace chemical analysis methods. It is a highly controversial
topic in analytical chemistry, and the controversy involves which
definition is most appropriate and meaningful for a given analytical
problem. The most widely accepted definitions involve a statistical
comparison of background noise to highly variable signals from
a small quantity of chemical that may be present in a sample.
Other definitions involve arbitrary cutoff levels chosen to minimize
the probability of false-positive decision errors (falsely claiming
to detect a chemical when it is actually not present at detectable
levels).
A detection limit definition
needs to be carefully and thoughtfully chosen for any particular
analytical method that may be used in forensic laboratories.
It may be more appropriate to define a method reporting limit
rather than a classically defined method detection limit. For
example, a reporting limit might correspond to the lowest concentration
or amount of chemical studied during method validation. This
reporting limit may be substantially higher than a classically
defined detection limit, but it may be sufficient for the intended
use of the laboratory's data. For qualitative methods, there
may be a need to define and estimate a minimum identifiable amount
as a performance characteristic. This quantity would reflect
the smallest amount of chemical that needs to be present in a
sample in order to achieve certain identification.
Ruggedness
This performance characteristic refers to the ability of a method
to withstand small changes in operating conditions without significantly
affecting the analytical results. Robustness is another
term used to describe this characteristic. Ruggedness studies
are typically conducted during method development studies. However,
many laboratories do not develop their own methods.
Methods may be obtained from
the scientific literature or from other laboratories. Therefore,
ruggedness studies may also be performed during method validation.
These studies are most appropriate for routine methods. They
are highly beneficial for the expedient identification of procedural
steps in a method that might cause difficulties if conditions
prescribed in the method are not critically controlled.
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Planning and Resources
Regardless of the method validation scenario, proper planning
will eventually enable laboratory personnel to efficiently and
effectively validate their methods. First, the analytical chemistry
applications in the laboratory need to be identified and categorized.
Technical working groups can be assembled to address method validation
issues for the various application areas. However, management
needs to support the efforts by providing adequate time for these
planning sessions.
A number of protocols or
standard operating procedures should be prepared to address method
validation issues relevant to each validation scenario and analytical
application area. These documents are not easy to create, and
a one-size-fits-all approach is usually ineffective. Generally
acceptable approaches may take months to create and document.
However, the process of creating such guidance documents generates
much thought and discussion among staff.
There are usually conflicting
opinions about which performance characteristics to study and
how to study them. When properly facilitated, the process of
creating method validation protocols or standard operating procedures
will eventually result in the best validation approaches for
the laboratory units.
Successful studies require
time, adequate funding, a high level of expertise, patience,
and extremely competent technical supervision. When new methods
are introduced into a laboratory, it may be necessary to purchase
equipment, special supplies, and additional types of chemicals.
More space may be needed for the installation of new equipment
and for conducting out-of-the-ordinary procedural steps. Specific
resource and planning issues are described in more detail in
the following sections.
Personnel
As with all other operational aspects of a laboratory, the quality
of the personnel involved is critical for successful method validation
efforts. Technical oversight needs to be provided by someone
with both technical and supervisory skills. This person should
have
- a thorough understanding
of the data quality objectives for a given measurement effort,
- excellent communication
skills (both oral and written), and
- a very high level of expertise
in analytical chemistry in addition to forensic science.
He or she must be able to
provide a critical review of methods and data and be open-minded
and objective. Personnel conducting the studies should understand
the goals of their validation efforts and the logic behind the
study designs. They must also have a high level of analytical
chemistry expertise, be observant, and be able to analyze and
interpret their data. Excellent documentation skills are also
required.
It may be beneficial to have
routinely scheduled technical meetings to discuss in-progress
validation efforts and data with all relevant staff. This provides
for objective input because it is sometimes difficult to maintain
a broad perspective when only a few people are immersed in highly
technical projects. Upon completion of a method validation study,
it is also highly beneficial to have a meeting with all staff
who will be using a particular method. The scientific principles
underlying the method can be explained, in addition to the performance
characteristics studied during validation. There may also be
a need for either formal in-house or external training for the
staff.
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Equipment, Chemicals, and Supplies
New methods and technological upgrades of currently used methods
may require the purchase of equipment, supplies, and chemicals.
Sources need to be identified, selection criteria need to be
established, and some items may require testing upon receipt.
There may be special installation or storage conditions that
require modification of the current arrangement of the laboratory.
In addition, there may be a need for new or modified standard
operating procedures that address equipment maintenance, storage
of supplies and chemicals, and disposal of chemicals that are
not currently in the laboratory's waste stream. Thus, the introduction
of new methodology and technological upgrades may affect several
components of a laboratory's quality assurance (QA) program,
and all method validation efforts should be reported to the QA
manager.
Space
The availability of adequate space is a common problem in laboratories.
Inadequate space has a direct impact on the ability of laboratory
personnel to implement analytical methods. Instruments that cannot
function properly in the space provided cause some method validation
problems and ongoing problems with QC data. In addition, adequate
workspace is needed for sample preparation steps to minimize
contamination and for health and safety purposes. Potential space
problems should be carefully assessed when new methods are being
implemented in a laboratory.
Scheduling
The validation of routine analytical methods takes time. The
amount of time depends on the study design, the expertise of
the technical supervisor and laboratory staff, and the number
of difficulties encountered with the application of a method
in a particular laboratory. One or more problematic procedures
in a method may require troubleshooting. On some occasions, it
is necessary to revert back to the method development stage so
that procedures can be reworked or optimized. The time invested
pays off substantially in the long run if a thorough study is
conducted that allows for the optimization of operating parameters
and a full understanding of method capabilities.
Potential Difficulties
There are several reasons for scientists to encounter difficulties
during method validation studies:
- Poorly documented methods,
- Inadequate time allocated
for background research,
- Insufficient technical expertise,
- Limitations of equipment,
- Inadequate chemicals or
supplies,
- Environmental conditions
in the laboratory,
- Too many modifications of
the original method, and
- Unknown or undocumented
critical control points.
There is no reason to assume
that a method developed and validated in one laboratory will
be easy to implement in another laboratory. Rugged and well-studied
methods have a greater chance of success when transferred between
laboratories.
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Summary
There are several managerial
practices that can improve the efficiency of method validation
efforts within a forensic laboratory. Appropriate laboratory
personnel should be notified as soon as possible when management
is considering an expansion of analytical services. The development
of new laws that will affect the nature of the analyses required
is one example of a potential expansion in analytical services
from the forensic laboratory.
When feasible, laboratory
directors could benefit from consulting with technical staff
prior to making commitments that may be difficult or impossible
to fulfill given current laboratory resources. Communication
among scientists in various laboratory units should be encouraged
to maximize use of the laboratory's expertise. Finally, supporting
educational outreach programs for laboratory customers (e.g.,
investigators and attorneys) will minimize misunderstandings
about the forensic laboratory's data and capabilities.
The goal is to have forensic
data that are admissible, scientifically valid, defensible, useful,
and generated as efficiently as possible. Properly designed method
validation studies will contribute to the achievement of this
goal.
References
1. Taylor, J. K. Validation
of analytical methods, Analytical Chemistry (1983) 55:
600A-608A.
2. Taylor, J. K. Quality
Assurance of Chemical Measurements. Lewis Publishers, Chelsea,
Michigan, 1987.
3. Mishalanie, E. A. Intra-Laboratory
[In-House] Analytical Method Validation Training Course Manual.
AOAC International, Gaithersburg, Maryland, 1997.
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The
National Forensic Laboratory Information System (NFLIS)
C. F. Richardson
Project Officer
U. S. Drug Enforcement Administration
Arlington, Virginia
The National Forensic Laboratory
Information System (NFLIS) is a U. S. Drug Enforcement Administration
(DEA) initiative to create a database of analyzed drug data from
state and local crime laboratories in the United States. The
primary purpose for creating the database is to provide accurate,
chemically verified data that can be used to support federal
drug scheduling actions. The data can also be useful in identifying
and following the spread of new drugs of abuse; documenting the
availability of abused drugs on the national, regional, and local
levels; and identifying changes in availability of abused drugs
geographically and chronologically.
The following is a time line
of the NFLIS database:
- September 1997: DEA awarded a five-year contract
to Research Triangle Institute (RTI) to design and develop the
NFLIS system.
- January 1998: RTI began to recruit laboratories
to report data to NFLIS.
- October 1998: RTI began receiving analyzed drug
data from recruited laboratories.
- August 1999: 53 recruited laboratories were reporting
data to RTI on a regular basis.
- September 1999: 99 laboratories agreed to participate
in the NFLIS.
- April 2000: An annual report will be available.
- May 2000: Regular quarterly reports on NFLIS
data will be available.
DEA provided technical and
financial assistance to many of these laboratories as incentives
to participate in the project.
Future plans for NFLIS include
recruiting additional laboratories and developing procedures
for participating laboratories and other organizations authorized
by DEA to access the data online.
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Forensic
Science Legislative Initiatives
J. J. St. Clair
Columbus Police Crime
Laboratory
Columbus, Ohio
B. A. J. Fisher
Los Angeles County
Sheriff's Office Crime Laboratory
Los Angeles, California
Crime laboratory directors
have become more involved as advocates for forensic science at
a federal level. As a result, federal assistance may become available
in the United States thanks to recent legislation as well as
liaisons with executive branch agencies.
The Crime Identification
Technology Act authorized $250 million "to provide for the
improvement of interstate criminal justice identification, information,
communications, and forensics." The FY 2000 appropriation
bill may fund the authorization, but the level of funding is
uncertain. A conference committee with U. S. House and Senate
members will determine the final amount.
The National Forensic Science
Improvement Act has been introduced in both the U. S. House and
Senate. If approved, it will authorize $768 million in block
grants for forensic science laboratories and medical examiners'
offices. It requires a state plan for improvements, and funds
must go to accredited laboratories or be used for the accreditation
process.
Crime laboratory directors
in the United States should contact their congressional representatives
and urge support for both pieces of legislation. Also, crime
laboratory directors should network with these representatives
and the men and women who work for them and make them aware of
issues faced by crime laboratories in their local areas.
Executive branch offices
such as the National Institute of Justice have traditionally
been a source of funding for forensic sciences. In addition to
this agency, other executive branch offices in the United States
hold the promise for future funding. These include the National
Science Foundation, the Office for Science and Technology Policy,
the Department of Energy, and the National Aeronautics and Space
Administration. Crime laboratory directors should seek out such
partnerships for future endeavors.
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FORENSIC SCIENCE COMMUNICATIONS JANUARY 2000 VOLUME
2 NUMBER 1 |