CITAC

In North America at the annual PittCon exposition there are papers and workshops concerning the future need for RMs, including the CITAC workshops. In Canada, in June 1993 in Quebec as part of the Annual Conference of the Canadian Society for Chemistry, a RM symposium was held lectures from it were the basis for a CRC RM book (Clement et al. 1997). Further examples include reports of regional activities in China (Chai 1993) and Australia (Millar et al. 1995). 

In compliance with EURACHEM/CITAC Guide 2 [72] polymer/additive analysis can be considered as a collection of discrete subtasks (Figure 1.3), each consisting of a number of unit processes, themselves composed of modules containing routine unit operations. The unit processes are characterised as being separated by natural dividing lines at which work can be interrupted and the test portion can be stored without detriment before the next step. 

EURACHEM Guidance Document No. CITAC Guide 2 QA Best Practice for Research and Development and Nonroutine Analysis, Working Draft 40, April 1997. Available from the EURACHEM Secretariat, Dept of Chemistry and Biochemistry, University of Lisbon, Portugal. 

A laboratory should draw up a plan of what performance checks are required for each instrument, why they are necessary and how they should be carried out. Maintenance intervals and performance checks for certain instruments are documented in the CITAC/Eurachem Guide to Quality in Analytical Chemistry [14]. 

Traceability in Chemical Measurement A Guide to Achieving Comparable Results in Chemical Measurement , Eurachem, Co-operation on International Traceability in Analytical Chemistry (CITAC), 2003. [http //www.eurachem.org]. 

These aims reach much further than the UK as evidenced by other international organizations which have developed, partly as a result of the work in VAM. They include Eurachem (a network of organizations in Europe having the objective of establishing a system for the international traceability of chemical measurements and the promotion of good quality practices) and CITAC (Co-operation on International Traceability in Analytical Chemistry). A wide variety of issues have been identified, all of which need to be addressed to ensure that analytical measurements made in different countries or at different times are comparable. 

The production of this book has been made possible through support from the VAM programme. The technical content of the book has also benefited through the results of work which has been carried out by LGC, often in collaboration with others, on specific technically based VAM, Eurachem and CITAC projects. 

Immunotoxins Antibody or antibody fragment (scFv, Fab, F(ab )2) Bacterial or plant toxin 3B3-PE ciTac-DT BerH2-SAP OM124-PAP [114] [115] [116.117] [117.118]... 

CITAC Cooperation on International Traceability in Analytical Chemistry http //www.citac.cc. 

More guidance on the way to accreditation may be found in the CITAC/EURACHEM guide mentioned here and the literature listed below. 

CITAC/EURACHEM (2002) Guide to Quality in Analytical Chemistry - An Aid to Accreditation, available from www.eurachem.org... 

This gives an overview of metrology in analytical chemistry as well as describing the role of measurement traceability. The traceability part of the presentation is based on the CITAC position paper on measnrement traceability (Traceability in Chemical Measurement, Accred. (Jual. Assm. (2000) 5 388-389)... 

Papadakis 1, Wegscheider W (2000) CITAC Position Paper Traceability in Chemical Measurement, Accred Qual. Assur 5 388-389... 

May W (1999) NIST SRMs. What they are, what they are NOT and their impact on the U.S. economy, international trade and quality of life. CITAC 99 Japan Symposium on Practical Realization of Metrology in Chemistry for the 21th Century, Nov 9-11, Tsukuba, Japan... 

To help other chemists the colleagues from an EURACHEM/CITAC working group did that transformation and fortunately included some examples. The guide is available from the internet free of charge. 

EURACHEM/CITAC-Guide Quantifying Uncertainty in Analytical Measurement ... 

The Uncertainty Estimation Process as described in the EURACHEM/CiTAC-guidecan be divided in 4 steps which are shown graphicaiiy beiow... 

The process to estimate the uncertainty as described in the GUM as well as in the EURACHEM/CITAC guide is divided in four steps. 

Once we know an estimate of the measurement uncertainty another problem comes up. How do we handle those uncertainties in compliance assessment The ideas described here are taken from a EURACHEM/CITAC- Guide. 

From EURACHEM/CITAC Guide "Use of uncertainty information in compliance assessment, 2007... 

EURACHEM/CITAC Quantifying Uncertainty in Analytical Measurement, 2nd Edition (2000) (www.eurachem.org)... 

EURACHEM, EURACHEM-CITAC Guide. The Eitnessfor Purpose of Analytical Methods A Laboratory Guide to Method Validation and Related Topics, EURACHEM Working Group, Teddington, U. K., 1998 (http //www.eurachem.ul.pt/index.htm). 

EURACHEM, EURACHEM- CITAC Guide. Quantifying uncertainty in analytical measurement, 2nd edn., EURACHEM Working Group, Teddngton, UK, 2000 (http //www.measure-mentuncertainty.org)... 

Eurachem/ CITAC A Focus for Analytical Chemistry in Europe/ Cooperation on International Traceability in Analytical Chemistry Traceability, MU, reference materials, validation 2,3 13,14,7,15... 

This definition is very much in line with the more practical definition described by Eurachem/CITAC [3]. Their procedure for traceability consists of the following steps [3] ... 

Sabe and Rauret [33] and Drolc et al. [34], however based upon the Eurachem/ CITAC guide on traceability [3]. In their examples, all authors take into account specific steps or influences in the analytical procedure which can lead to a broken chain of comparisons, such as sampling and sample treatment or preparation steps. Some authors have reported on uncertainties associated with sampling in particular [35,36]. 

Eurachem/ CITAC and EA A Focus for Analytical Chemistry in Europe/Cooperation of International Traceability in Analytical Chemistry and European Cooperation for Accreditation Method validation, Proficiency testing, QA, accreditation 2,15, 59-60... 

Accreditation is a formal recognition that a laboratory is competent to carry out specific (types of) calibrations or tests [2]. After the use of validated and standardized methods, the introduction and use of appropriate IQC procedures and the participation in PT schemes, accreditation to ISO/IEC 17025 is the fourth basic principle related to laboratory QA in general [4]. Guidelines on the implementation of ISO/IEC 17025, including the estimation of MU (see also Section 8.2.2), are published in the literature and by official accreditation bodies such as Eurachem, CITAC, EA, Eurolab, and ILAC (see Table 1) [2,60, 80, 81,110]. It is worthwile to mention that accreditation, just like participance in PT schemes, does not necessarily indicate good performance of the laboratory [108]. 

EURACHEM (2000), Quantifying uncertainty in analytical measurement, 2nd ed., M. Rosslein S.L.R. Ellison, A. Williams (eds.) (EURACHEM/CITAC,... 

Primary calibrators, indeed all calibrators, must be commutable that is, they must behave during measurement in an identical manner to the native analyte material being measured. Matrix reference materials made by mixing a pure reference material with the components of the matrix are unlikely to be entirely commutable, and for this reason some authorities (EURACHEM for one [EURACHEM and CITAC 2002]) advise against using matrix-matched CRMs for calibration, recommending instead their use to establish recoveries, after calibration by a pure reference standard. 

EURACHEM and CITAC (2002), Traceability in chemical measurement, EURACHEM/CITACguide, 1st ed. (EURACHEM/CITAC Teddington UK). 

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