1 Lecture 7 Analytical Quality Control Moncef Benmansour CNESTEN, Morocco IAEA Regional Training Course Sediment Core Dating Techniques - RAF/7/008 Project.

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Lecture 7Lecture 7

Analytical Quality ControlAnalytical Quality Control

Moncef BenmansourMoncef Benmansour

CNESTEN, MoroccoCNESTEN, Morocco

IAEA Regional Training Course

Sediment Core Dating Techniques - RAF/7/008 Project

CNESTEN, Rabat, 05-09 July 2010CNESTENIAEA

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ContentContent

Quality Assurance and Quality ControlQuality Assurance and Quality Control

Reliabilty of the ResultsReliabilty of the Results

Internal programme Internal programme

External programmeExternal programme

ExamplesExamples

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QA and QCQA and QC

Quality (ISO)Quality (ISO)– The totality of features and characteristics of a The totality of features and characteristics of a

product, process or service that bear on its ability product, process or service that bear on its ability to satisfy stated or implied needsto satisfy stated or implied needs

Quality assurance (ISO):Quality assurance (ISO):

– All those planned and systematic actions All those planned and systematic actions necessary to provide adequate confidence that a necessary to provide adequate confidence that a product, process or service will satisfy given product, process or service will satisfy given quality requirementsquality requirements

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QA and QCQA and QC

Quality Control (ISO):Quality Control (ISO):

– The Operational technique and activities that The Operational technique and activities that are used to satisfy quality requirementare used to satisfy quality requirement

– The overall system of activities whose purpose The overall system of activities whose purpose is to control the quality of a product or service is to control the quality of a product or service so that it meets the needs of users. The aim is so that it meets the needs of users. The aim is to provide quality that is satisfactory, to provide quality that is satisfactory, adequate, dependable and economic. It adequate, dependable and economic. It represents the mechanism established to represents the mechanism established to control errors.control errors.

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QA and QC QA and QC

Good Quality control Good Quality control

– Use of Reliable qualified personnel and well-Use of Reliable qualified personnel and well-maintained instrumentationmaintained instrumentation

– Use of appropriate standards for calibrationUse of appropriate standards for calibration

– Use of Certified Reference Materiel or Reference Use of Certified Reference Materiel or Reference MaterialMaterial

– Analyses of blind and blank samplesAnalyses of blind and blank samples

– Use of Control Chart Use of Control Chart

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Terminology QA and QC: BasisTerminology QA and QC: Basis

Quality assessmentQuality assessment– The overall system whose purpose is to provide The overall system whose purpose is to provide

assurance that the quality control activities are assurance that the quality control activities are being done effectively. It is a form of control in being done effectively. It is a form of control in which intra-laboratory and inter-laboratory testing which intra-laboratory and inter-laboratory testing programs ply a major roleprograms ply a major role

Good Laboratory PracticesGood Laboratory Practices– GLP describes how a laboratory should work, how it GLP describes how a laboratory should work, how it

should be organised and how it can produce valid should be organised and how it can produce valid datadata

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Terminology QA and QC: BasisTerminology QA and QC: Basis

Major items in a quality assessment Major items in a quality assessment programmeprogramme

– Facilities, organisation and personnel,Facilities, organisation and personnel,– Equipment, consumables, chemicals, Equipment, consumables, chemicals, – DocumentationDocumentation– Sampling and storageSampling and storage– Laboratory analysisLaboratory analysis– Final resultsFinal results– Quality assessmentQuality assessment

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Precision : ReproducibilityPrecision : Reproducibility– Precision refers to the repeatability Precision refers to the repeatability

of measurement. It does not require of measurement. It does not require us to know the correct or true valueus to know the correct or true value

Accuracy : True ValueAccuracy : True Value– Accuracy refers to the Accuracy refers to the agreementagreement of of

the measurement and the true valuethe measurement and the true value

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Not accurateNot precise

AccurateNot precise

Not accuratePrecise

AccuratePrecise

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Uncertainty:Uncertainty:– Uncertainty of a measured value is an interval Uncertainty of a measured value is an interval

around that value such that any repetition of around that value such that any repetition of the measurement will produce a new result the measurement will produce a new result that lies within this interval. This uncertainty that lies within this interval. This uncertainty interval is assigned by the experimenter interval is assigned by the experimenter following established principles of uncertainty following established principles of uncertainty estimationestimation

Errors: Errors: – Error refers to the disagreement between a Error refers to the disagreement between a

measurement and the true or accepted valuemeasurement and the true or accepted value

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Internal Programme: PrecisionInternal Programme: Precision

Equipment performancesEquipment performances– Stability of backgroundStability of background– Stability of efficiency and energy resolutionStability of efficiency and energy resolution

All sources of uncertaintiesAll sources of uncertainties– Counting measurementsCounting measurements– Standard sourcesStandard sources– Physical and chemical preparationPhysical and chemical preparation– CalibrationCalibration– Correction factorsCorrection factors

Analytical control of SamplesAnalytical control of Samples– Internal standards: High and low activitiesInternal standards: High and low activities– BlanksBlanks

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Internal Programme: PrecisionInternal Programme: Precision

Use of control chart:Use of control chart:– Graphical way to interpret test data and to monitor Graphical way to interpret test data and to monitor

the measurement process or the status of an the measurement process or the status of an instrumentinstrument

X Chart X Chart

– Single measurements : XSingle measurements : X– Mean value : XMean value : Xmeanmean

– Upper Control Limit : UCLUpper Control Limit : UCL– Lower Control Limit LCLLower Control Limit LCL– Upper Warning Limit : UWLUpper Warning Limit : UWL– Lower Warning Limit : LWL Lower Warning Limit : LWL

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Use of control chart:Use of control chart:

3 meanXUCL

3 meanXLCL

2 meanXUWL

2 meanXLWL

)1/()( 2

1

nXXn

imeani

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Control Chart: FWHM ( keV)Control Chart: FWHM ( keV)- Energy Resolution -- Energy Resolution -

1

1,2

1,4

1,6

1,8

2

2,2

2,4

0 1 2 3 4 5 6 7 8

Analyse N°

FWH

M (k

eV)

FWHM (662 keV)

2LWL

2UWL

MEAN

2LCL

2UCL

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Control Chart: Efficiency: 662 Control Chart: Efficiency: 662 keVkeV

0,0152

0,0154

0,0156

0,0158

0,016

0,0162

0,0164

0,0166

0 1 2 3 4 5 6 7 8 9 10 11

Analyse N°

Eff

Eff (662 keV)

LWL

UWL

MEAN

LCL

UCL

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External Programme: Accuracy External Programme: Accuracy

Certified Reference MaterialCertified Reference Material

Intercomparison exercise ( Intercomparison exercise ( IAEA/MEL) IAEA/MEL)

Proficiency test ( IAEA/RMG)Proficiency test ( IAEA/RMG)

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Certified Reference Certified Reference MaterialMaterial

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Interlaboratory test Interlaboratory test

The goal is to demonstrate that participating to The goal is to demonstrate that participating to intercomparison exercise and proficiency tests intercomparison exercise and proficiency tests leads to improved quality of analytical results. leads to improved quality of analytical results.

The result are of crucial interest for laboratories The result are of crucial interest for laboratories as these provide clear information of its as these provide clear information of its measurement capabilities. measurement capabilities.

It would be pointed out that the participation is It would be pointed out that the participation is either voluntary or forced by external either voluntary or forced by external requirements (e.g. legal, accreditation, control requirements (e.g. legal, accreditation, control bodiesbodies

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External Programme: AccuracyExternal Programme: Accuracy

Intercomparison exercise: Intercomparison exercise: MEL/IAEAMEL/IAEA

– Scope of the IntercomparisonScope of the Intercomparison– Description of the materialDescription of the material– Homogeinisation and TestsHomogeinisation and Tests– Sample Dispatching and Data returnSample Dispatching and Data return– Evaluation of the resultsEvaluation of the results

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Intercomparison exercice Intercomparison exercice (IAEA/MEL): Example of 137Cs(IAEA/MEL): Example of 137Cs

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Intercomparison exercice Intercomparison exercice (IAEA/MEL): Example of 239, 240Pu(IAEA/MEL): Example of 239, 240Pu

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Intercomparison exercice Intercomparison exercice (IAEA/MEL): (IAEA/MEL): Z score: value acceptable if Z score: value acceptable if I z II z I ≤≤ 2 2

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Proficiency test : IAEA Proficiency test : IAEA Reference material group - Reference material group - SeibersdorfSeibersdorf

Introduction: ObejectiveIntroduction: Obejective

Material and methodsMaterial and methods

Performance criteriaPerformance criteria

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Trueness and PrecisionTrueness and Precision– A: AcceptableA: Acceptable

– N: Not AcceptableN: Not Acceptable

– W: WarningW: Warning

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Trueness Trueness

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Precision Precision

P ≤ LAP: Limit of Acceptable Precision

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Z scoreZ score

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Example: IAEA/PT, Analyse of Example: IAEA/PT, Analyse of 137137Cs and Cs and 210210Pb in soil samplePb in soil sample

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Source of errorsSource of errors

1 Lecture 7 Analytical Quality Control Moncef Benmansour CNESTEN, Morocco IAEA Regional Training Course Sediment Core Dating Techniques - RAF/7/008 Project.

Documents

quality control reliabilty

qc quality iso quality

quality control activities

qc quality control iso

content quality assurance

given quality requirements

control chart slide

true value slide