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Wenclawiak, B.: Fit for Purpose – A Customers View© Springer-Verlag Berlin Heidelberg 2003 In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and Teaching Analytical measurements should be made to satisfy an agreed requirement
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In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Fit for Purpose -A Customers View
Bernd Wenclawiak
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Analytical measurements should be made to satisfy an agreed requirement
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Analytical measurements should be Analytical measurements should be made using methods and equipment made using methods and equipment
which have been tested to ensure which have been tested to ensure they are they are
fit for purposefit for purpose
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Staff making analytical measurements Staff making analytical measurements should be both:should be both:qualified and competent to undertake the task and to undertake the task and demonstrate that they can perform demonstrate that they can perform the analysis properlythe analysis properly
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
There should be a regular independent There should be a regular independent assessment of the technical assessment of the technical performance of a laboratoryperformance of a laboratory
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Analytical measurements Analytical measurements made in one location made in one location should be consistent should be consistent
with those made elsewherewith those made elsewhere
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Organizations making analytical Organizations making analytical measurements should have well measurements should have well
defined quality control and defined quality control and quality assurance proceduresquality assurance procedures
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Method validation is an important Method validation is an important requirement in the practice of requirement in the practice of
chemical analysischemical analysis
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
What is Validation?
Confirmation by examination and provision of objective evidence that the particular requirements for a specified intended use are fulfilled
ISO 8402 (1994)
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
What is Method Validation? - 1 The process of establishing the performance
characteristics and limitations of a method and the identification of the influences which may change these characteristics and to what extent.
Which analytes can it determine in which matrices in the presence of which interferences?
Within these conditions what levels of precision and accuracy can be achieved?
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
What is Method Validation? - 2
The process of verifying that a method is fit for purpose, i.e. for use for solving a particular analytical problem
This means the method must be suitable
Method validation is not solely the process of evaluating the performance parameters
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
The Method Validation Process Implies:
the use of equipment within its specifications
that the operator is fit for purpose
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Why is Method Validation Necessary?
Importance of analytical measurement
The professional duty of the analytical chemist
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
When should Methods be When should Methods be Validated ?Validated ?
Comparing methods
Replacement of instruments
Change of operator
Other significant changes
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated?
Who carries out method validation? Deciding what degree of validation is
required The analytical requirement
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Choosing, Developing and Evaluating Methods
Problem requiring chemical analysis:
Set analytical requirement
Identify existing method or develop
new method
Further development
feasible?
Evaluatemethod – fit for
purpose as used inthe laboratory
Relaxanalytical
requirement?
Developmethod
Analytical work proceeds
Analytical requirement re-stated in terms of
what has been accomplished
Unable to do work – subcontract?
End
Yes
Yes Yes
No No
No Method validation consists of this evaluation stage, together with any performance parameters that may be evaluated under method development
„Fit for purpose...“ . Regardless of what existing performance data may be available for the method, fitness for purpose will be
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated?
Who carries out method validation?
Deciding what degree of validation is required
The analytical requirement
Method Development The different performance parameters
of a method and what they show
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated?
The different performance parameters of a method and what they show Confirmation of identity and selectivity/specificity Limit of detection Limit of quantitation Working and linear ranges Accuracy Trueness
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated? Interpreting bias measurements
Measured value(laboratory mean)
True value
Interlaboratorymean
Total bias
Laboratory bias Method bias
Note: Laboratory and method biases are shown here acting in the same direction.In reality this is not always the case
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated? The different performance parameters of a
method and what they show Confirmation of identity and selectivity Limit of detection Limit of quantitation Working and linear ranges Accuracy Trueness Interpreting bias measurements
precision repeatability reproducibility sensitivity ruggedness or robustness recovery
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
How should Methods be Validated? The different performance parameters of a method and
what they show Confirmation of identity and selectivity Limit of detection Limit of quantitation Working and linear ranges Accuracy Trueness Interpreting bias measurements precision repeatability reproducibility sensitivity ruggedness-robustness recovery
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
The Tools of Validation Blanks reagent blanks sample blanks Samples/test materials fortified materials/solutions spiked materials incurred materials independently characterised materials (Measurement) Standards Reference Materials Certified reference materials Statistics Replication
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Using Validated Methods
Two issues to consider: are existing validation data adequate is the analyst sufficiently competent
can he achieve the performance level claimed in the method?
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Rules Recommended to Ensure Acceptable Performance
Analyst should be familiar with method before using it for the first time Work firstly under supervision get training think ahead of process, solutions etc required
Make an assessment how many samples can be handled at a time
Make sure everything needed is available before work starts
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Using Validation Data to Design QC
Internal QC
External QC
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Using Validation Data to Design QC
Internal QC includes: blanks chemical calibrants spiked samples blind samples replicate analysis QC samples control charts (recommended)
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Using Validation Data to Design QC
External QC e.g. proficiency testing (external quality
assessment) participation in proficiency testing schemes
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Documentation of Validated Methods 1
When the validation process is complete document the procedures of the method (also important for auditing and evaluation purposes)
With appropriate documentation reuse of method is more consistent uncertainty contribution is decreased
Test quality of documentation with a competent colleague
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Documentation of Validated Methods 2 Standard guidance for documentation is
found in ISO 78 series “house style” is also adequate Documented methods form an important part
of a lab’s quality system document control
is documentation complete authorized for use which version which date author copyrights when last updated
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Method Documentation Protocol
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Implications of Validation Data for Calculating Results and Reporting
Translate data in results to solve customers problem
Consider: are observed differences significant?
precision data for repeatability and reproducibility Quality controls confirm method is in control
based on validation data producing meaningful results Estimation of measurement uncertainty enables
expression for level of confidence
In: Wenclawiak, Koch, Hadjicostas (eds.) Quality Assurance in Analytical Chemistry – Training and TeachingWenclawiak, B.: Fit for Purpose – A Customers View © Springer-Verlag Berlin Heidelberg 2003
Implications of Validation Data for Calculating Results and Reporting
The analyst needs access to validation data to support validity of results The customer may not need or understand
it Information about uncertainties might
not be understood by everybody (lawyers) When required: uncertainty should be
reported (confidence limits e.g. 95 %)
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