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27th Annual Symposium on Crime Laboratory Development: Abstracts of Presentations (Forensic Science Communications, January 2000)

27th Annual Symposium on Crime Laboratory Development: Abstracts of Presentations (Forensic Science Communications, January 2000)

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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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