1. Lecture 7 Analytical Quality Control
IAEA Regional Training Course
Sediment Core Dating Techniques - RAF/7/008 Project
CNESTEN, Rabat, July 2010
CNESTEN
IAEA
Lecture 7 Analytical Quality Control
Moncef Benmansour
CNESTEN, Morocco

2. Content
Quality Assurance and Quality Control
Reliabilty of the Results
Internal programme
External programme
Examples

3. Quality assurance (ISO):
QA and QC
Quality (ISO)
The totality of features and characteristics of a product, process or service that bear on its ability to satisfy stated or implied needs
Quality assurance (ISO):
All those planned and systematic actions necessary to provide adequate confidence that a product, process or service will satisfy given quality requirements

4. QA and QC Quality Control (ISO):
The Operational technique and activities that are used to satisfy quality requirement
The overall system of activities whose purpose is to control the quality of a product or service so that it meets the needs of users. The aim is to provide quality that is satisfactory, adequate, dependable and economic. It represents the mechanism established to control errors.

5. QA and QC Good Quality control
Use of Reliable qualified personnel and well-maintained instrumentation
Use of appropriate standards for calibration
Use of Certified Reference Materiel or Reference Material
Analyses of blind and blank samples
Use of Control Chart

6. Terminology QA and QC: Basis
Quality assessment
The overall system whose purpose is to provide assurance that the quality control activities are being done effectively. It is a form of control in which intra-laboratory and inter-laboratory testing programs ply a major role
Good Laboratory Practices
GLP describes how a laboratory should work, how it should be organised and how it can produce valid data

7. Terminology QA and QC: Basis
Major items in a quality assessment programme
Facilities, organisation and personnel,
Equipment, consumables, chemicals,
Documentation
Sampling and storage
Laboratory analysis
Final results
Quality assessment

8. Reliabilty of the Results
Precision : Reproducibility
Precision refers to the repeatability of measurement. It does not require us to know the correct or true value
Accuracy : True Value
Accuracy refers to the agreement of the measurement and the true value

9. Reliabilty of the Results

10. Reliabilty of the Results
Uncertainty:
Uncertainty of a measured value is an interval around that value such that any repetition of the measurement will produce a new result that lies within this interval. This uncertainty interval is assigned by the experimenter following established principles of uncertainty estimation
Errors:
Error refers to the disagreement between a measurement and the true or accepted value

11. Internal Programme: Precision
Equipment performances
Stability of background
Stability of efficiency and energy resolution
All sources of uncertainties
Counting measurements
Standard sources
Physical and chemical preparation
Calibration
Correction factors
Analytical control of Samples
Internal standards: High and low activities
Blanks

12. Internal Programme: Precision
Use of control chart:
Graphical way to interpret test data and to monitor the measurement process or the status of an instrument
X Chart 
Single measurements : X
Mean value : Xmean
Upper Control Limit : UCL
Lower Control Limit LCL
Upper Warning Limit : UWL
Lower Warning Limit : LWL

13. Use of control chart:

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

15. Control Chart: Efficiency: 662 keV

16. External Programme: Accuracy
Certified Reference Material
Intercomparison exercise ( IAEA/MEL)
Proficiency test ( IAEA/RMG)

17. Certified Reference Material

18. Interlaboratory test
The goal is to demonstrate that participating to intercomparison exercise and proficiency tests leads to improved quality of analytical results.
The result are of crucial interest for laboratories as these provide clear information of its measurement capabilities.
It would be pointed out that the participation is either voluntary or forced by external requirements (e.g. legal, accreditation, control bodies

19. External Programme: Accuracy
Intercomparison exercise: MEL/IAEA
Scope of the Intercomparison
Description of the material
Homogeinisation and Tests
Sample Dispatching and Data return
Evaluation of the results

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

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

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

23. Proficiency test : IAEA Reference material group - Seibersdorf
Introduction: Obejective
Material and methods
Performance criteria

24. Proficiency test : IAEA Reference material group - Seibersdorf
Trueness and Precision
A: Acceptable
N: Not Acceptable
W: Warning

25. Proficiency test : IAEA Reference material group - Seibersdorf
Trueness

26. Proficiency test : IAEA Reference material group - Seibersdorf
Precision
P ≤ LAP: Limit of Acceptable Precision

27. Proficiency test : IAEA Reference material group - Seibersdorf
Z score s

28. Proficiency test : IAEA Reference material group - Seibersdorf

29. Example: IAEA/PT, Analyse of 137Cs and 210Pb in soil sample

30. Example: IAEA/PT, Analyse of 137Cs and 210Pb in soil sample

31. Example: IAEA/PT, Analyse of 137Cs and 210Pb in soil sample

32. Example: IAEA/PT, Analyse of 137Cs and 210Pb in soil sample

33. Example: IAEA/PT, Analyse of 137Cs and 210Pb in soil sample
Source of errors