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It is being increasingly used in the analytical

Traceability is a generic, basic concept, inherent in Analytical Chemistry (the science of chemical measurements). It is being increasingly used in the analytical chemistry domain because of the growing of the analytical Quality Systems.

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It is being increasingly used in the analytical

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  1. A. Ríos Traceability / Trackability Traceability is a generic, basic concept, inherent in Analytical Chemistry (the science of chemical measurements). It is being increasingly used in the analytical chemistry domain because of the growing of the analytical Quality Systems. T The definitions from dictionaries (1,2) deal with 1. Traceability (noun) : ‘the quality of being traceable’. 2. Traceable(adjective) : ‘capable of being traced’; ‘suitable or of a kind to be attributed’. 3. To trace (verb) : ‘to follow or study out in detail or step by step’; ‘to follow the course, development or history of’;‘to outline or present the development, progress or history of’. (1) Oxford English Dictionary, Oxford University Press, Oxford, 2nd Edition, 1989 (2) Webster’s Third New International Dictionary, Merrian- Webster, Chicago, 1981.

  2. A. Ríos Traceability / Trackability Measurement(s) RESULTS SYSTEM UNDER STUDY Physical measurements Sample Results CALIBRATED EQUIPMENT Chemical measurements VALIDATED ANALYTICAL PROCESS Sample Results

  3. A. Ríos Traceability / Trackability TRACEABILITY / TRACKABILITY Definitions and meanings. T

  4. A. Ríos Traceability / Trackability Definitions TRACEABILITY (ISO, 1984) The property of a result of a measurement whereby it can be related to appropriate standards, generally international or national standards, through an unbroken chain of comparisons. Analytical result CONCENTRATION (ISO Guía 25) TRACEABILITY REFERENCE KILOGRAM analyte weight sample weight TRACEABILITY (ISO, 1993) Property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties. CHEMICAL REFERENCE M ±N

  5. A. Ríos Traceability / Trackability S.I. BASICSTANDARDS KG AMPERE MOL SECOND NAVOGADRO WEIGHTOF C-12 CHEMICALSTANDARDS FARADAY ATOMICWEIGHTS ULTRAPURESILVER PRIMARYSTANDARDS ANALYTICALSTANDARDS Operational standards WORKINGSTANDARDS

  6. A. Ríos Traceability / Trackability A RESULTS LAB. 1 STANDARDS A B B A A RESULTS LAB. 2 STANDARDS BASE(S.I. units)STANDARDS B B B A STANDARDS RESULTS LAB. 3 A

  7. A. Ríos Traceability / Trackability Analytical / Metrological properties M±N TRUENESS TRACEABILITY PRECISION UNCERTAINTY

  8. A. Ríos Traceability / Trackability SAMPLE ANALYTICAL PROCESS RESULTS • In a general analytical process, traceability is assured • through: • TRACEABILITY OF MEASUREMENT STANDARDS. • CALIBRATION (apparatus + instruments). • VALIDATION OF THE OVERALL ANALYTICAL PROCESS.

  9. A. Ríos Traceability / Trackability Demonstrating traceability of analytical results SAMPLE ANALYTICAL PROCESS RESULTS CRM (matrix type) Comparison against the certified value t test : texp < tcrit (P, n-1, 2 tails)

  10. A. Ríos Traceability / Trackability Primary methods References and their hierarchy Certified reference materials Reference methods Collaborative studies Working reference materials Reference instruments Material formulation Spiked samples Alternative techniques

  11. A. Ríos Traceability / Trackability Example : G R A V I M E T R Y standard kilogram certified weights (CALIBRATION) dissolution OH 3+ Fe Fe O Fe(OH) SAMPLE 2 3 3 2 Fe 12 g Fe = (Product weight) mol , C Fe O WEIGHTS 2 3

  12. A. Ríos Traceability / Trackability Example : T I T R A T I O N S Standard-kg certified weights TITRATING (CALIBRATION) VOLUME (standardisation?) 12 mol , C CALIBRATION TITRANT SOLUTION VA NA = VB NB fB WEIGHT V N f PRIMARY WEIGHT B B B N A STANDARD (sample) V A

  13. A. Ríos Traceability / Trackability Example : INSTRUMENTAL ANALYSIS SAMPLE Standard kilogram certified weights SAMPLE PREPARATION (CALIBRATION) Signal • • SAMPLE MEASUREMENT • • CALIBRATED INSTRUMENT • • • Conc. y = a + bx CHEMICAL STANDARD ANALYTICAL CALIBRATION  “CALIBRATION OF EQUIPMENTS” (to be sure that the equipment works appropriately in a general way) “ANALYTICAL CALIBRATION” (to define the specific relationship between the instrumental signal and the concentration of a particular species)

  14. A. Ríos Traceability / Trackability ISO 8402-94 Quality Management and Quality Assurance Vocabulary (1994). TRACEABILITY Ability to trace the history, application or location of an entity by means of recorded identifications. TRACING CONNOTATION 1. THE TERM TRACEABILITY MAY HAVE ONE OF THREE MAIN MEANINGS: (a) In a productive sense, it may be related to: 1. The origin of materials and parts. 2. The product processing history. 3. The distribution and location of the product after delivering. (b) In a calibration sense, it relates measuring equipment to national or international standards, primary standards, basic physical constants or properties, or reference materials. (c) In a data collection sense, it relates calculations and data generated throughout the quality loop, sometimes back to requirements for quality for an entity. 2.. ALL ASPECTS OF TRACEABILITY REQUIREMENTS, IF ANY, SHOULD BE CLEARLY SPECIFIED (for instance, in terms of period or time, point of origin or identification).

  15. A. Ríos Traceability / Trackability ACCURACY 'TARGET' T R A C E A B I L I T Y

  16. A. Ríos Traceability / Trackability • ISO (International Vocabulary of Basic and General Terms in Metrology ) “ Property of a result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international, through an unbroken chain of comparisons all having stated uncertainties “ · ISO 8402-94 (Quality Management and Quality Assurance Vocabulary ) “ The ability to trace the history, application or location of an entity by means of recorded identifications “

  17. A. Ríos Traceability / Trackability HISTORY OF THE GENERATION OF A PRODUCT OR THE BEHAVIOUR OF A SYSTEM TRACEABILITY Integral approach RELATIONSHIP TO REFERENCES

  18. A. Ríos Traceability / Trackability The integral approach of traceability “STANDARDS” Ability to relate entities with well-established landmarks or references • NORMS • ENVIRONMENTAL STANDARDS • (criteria, limits, etc.) Written standards (INTANGIBLE) STANDARDS • PROCEDURES Measurement standards (TANGIBLE) • OBJECTS • (v.i. a CRM)

  19. A. Ríos Traceability / Trackability “ TRACKABILITY “ J. Fleming, B. Neidhart, Ch. Tausch and W. Wegscheider. Accreditation & Quality Assurance, 1 (1996) 43. • The property of a result of a measurement whereby the result can be uniquely related to the sample (The result of a measurement can be linked unambiguously to the sample to which it refers) RESULT CALCULATION DETERMINATION SEPARATION PREPARATION STORAGE SAMPLING

  20. A. Ríos Traceability / Trackability “Trackability is not a property of the results of measurement but more a property of the system” The definition should be: “The property of a system which enables the ready retrieval of the different elements of a record to allow unambiguous correlation with an uniquely identified sample” J. Fleming, H. Albus, B. Neidhart and W. Wegscheider Accred. Qual. Assur. (1996) 1, 234.

  21. A. Ríos Traceability / Trackability TRACEABILITY / TRACKABILITY ? Do we need the ‘trackability’ term T

  22. A. Ríos Traceability / Trackability Traceability in Analytical Chemistry Miguel Valcárcel and Angel Ríos The Analyst, 120 (1995) 2291-2297. ECONOMIC ORSOCIAL PROBLEM ANALYTICALPROBLEM REPRESENTATIVENESS OBJECT BULK SAMPLE SAMPLESALIQUOTS ANALYTICALPROCESS RESULTS SAMPLE CUSTODY CHAIN

  23. A. Ríos Traceability / Trackability Why not a wider definition of traceability ? Property of a result of a measurement, linked unambiguously to the sample to which it refers, or the value of a standard whereby it can be related to stated references, usually national or international, through an unbroken chain of comparisons all having stated uncertainties; and the ability to trace the history, application or location of all the elements involved in the generation of such result by means of recorded identifications.

  24. A. Ríos Traceability / Trackability TRACEABILITY of . . . Related to its SAMPLE Related to STANDARDS A RESULT A STANDARD AN EQUIPMENT A SAMPLE A METHOD ( Representativeness ) ( Traceable methods ) IS TRACEABILITY AN EXCLUSIVE PROPERTY OF ANALYTICAL RESULTS ? An extended approach to traceability in chemical analysis. M. Valcárcel and A. Ríos Fresenius J. Anal. Chem. (1997) 359: 473-475.

  25. A. Ríos Traceability / Trackability TRACEABILITY OF A RESULT HISTORY OF ITS GENERATION • Elements defining and documenting the “history” of a result. WHO ? HUMAN MATERIAL WHAT ? INSTRUMENTAL METHODOLOGICAL HOW ? ENVIRONMENTAL WHEN ? TEMPORAL

  26. A. Ríos Traceability / Trackability TRACEABILITY OF A CRM (1) PREPARATION - Origin of the material (natural or artificial). - Analytes spiked or originally contained. - Studies performed on both homogeneity and stability. - Etc. (2) CERTIFIED VALUES - How the values and their uncertainties were established. - Methods used. - Values rejected and reasons. - Standards used by the participating laboratories. - Major sources of error. - Etc. EXAMPLE: Certified reference materials for determination of PCBs in soil samples(*) Recovery ( % ) SFE operational conditions SRM (NIST) CRM (BCR) EXPE- RIENCE T ( oC) P (atm) Density Time (g/ml) (min) Analytes spiked to clean soil Analytes origin- ally contained (1) (2) (3)(#) 40 40 60 200 150 300 0. 84 0. 78 0. 83 30 30 30 99 % 99 % 99 % 25 % 30 % (#)100 µL of MeOH previously added to the CRM (*)From P. Sandra

  27. A. Ríos Traceability / Trackability TRACEABILITY OF AN EQUIPMENT • DETAILED, TIMELY AND CUSTOMIZED RECORDING OF: • CONSISTENCY WITH ISO’S DEFINITION (ISO 8402-94). • ISO 9000, EN 45000: ESSENTIAL PART OF QUALITY MANUAL. • GLPs: EACH EQUIPMENT MUST HAVE A ‘SOP’. Installation. Breakdowns. Calibrations and corrections. Hours of use. Samples processed. Etc.

  28. A. Ríos Traceability / Trackability TRACEABILITY OF METHODOLOGIES “Official”, “standards” and “ “reference” methods do not assure the quality of the results. Even methods validated by interlaboratory exercises can produce poor results if incorrectly used. 1. In its development. 2. In its routine application. TRACEABLE METHOD Method that produces results (with their uncertainties) characterised by traceability to established references. “ESTABLISHED REFERENCES”: - Certified reference materials. - Primary methods. Primary measurement method - Highest metrological quality. - Its operations must be thoroughly known and explained. - Its uncertainty must be thoroughly described in terms of basic SI units. - Its results must be accepted without reference to standards of the measured quantity. GRAVIMETRY COULOMETRY ISOTOPIC DILUTION - MS

  29. A. Ríos Traceability / Trackability TRACEABILITY / TRACKABILITY T Final remarks TRACEABILITY Characteristic of an entity. Characteristic of a measuring equipment (in the calibration domain). OFFICIAL POSITION IN THE QM DOMAINS ORTHODOX APPROACH OFFICIAL METROLOGICAL POSITION Property of a result of a measurement. Characteristic of the value of a standard. Metrological characterisation in the chemical measurement domain applicable to aspects such as: - RESULTS - STANDARDS - MEASURING EQUIPMENT - SAMPLE (aliquot) - METHODOLOGIES (QUASI-) HETERODOX APPROACH Emphasis on tracing connotation (QA principles). TRACKABILITY - New term or new (implicit) facet of traceability concept ? - Is it necessary a new integrated definition of traceability ?

  30. A. Ríos Traceability / Trackability TRACEABILITY / TRACKABILITY T Some challenges  To make the concepts understandable and accessible so that they are no longer the exclusive patrimony of theoreticians and bureaucrats.  To make the concept of traceability more flexible and practical, in order to facilitate its use.  To expose the fallacy that traceability can only be acceptably referred to the mole and/or kilogram (SI units). Traceability to a well established accessible standard is also quite valid, practical and useful.  To avoid useless arguments (e.g. the MOLE vs. the kg as the ultimate reference in chemical metrology).  To systematically introduce the concepts in Analytical Chemistry education and research.

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