Intercomparison exercises

Mee LD, Oregioni B, and Horvat M (1992) Worldwide and regional intercomparison exercise for the determination of trace elements in tuna fish homogenate sample IAEA-350. Report IAEA/AL/052, IAEA-MEL, Monaco. 

Topping G (1982) Report on the sixth ICES trace metal intercomparison exercise for cadmium and lead in biological tissue. ICES Cooperative Research Report No in. International Council for the Exploration of the Sea, Copenhagen, Denmark... 

Marchetto, A., Mosello, R., Tartari, G. A., Muntau, H., Bianchi, M., Geiss, H., Serrini, G. and Fanza, G. S., Precision of ion chromatographic analyses compared with that of other analytical techniques through intercomparison exercises, /. Chromatogr. A, 706, 13, 1995. 

Determinations of the so-called micronutrients , (e.g., nitrate, phosphate, and dissolved silica), in seawater are among the most commonly performed analyses in oceanographic research and survey work. Surprisingly, there exists no certified reference material that can be used to check the accuracy of such analyses, although intercomparison exercises have been conducted on a regular basis [243 ]. The lack of seawater certified reference material for micronutrients can be attributed both to the difficulty of preparing a suitable material with an adequate shelf life [244,245] and to the dearth of independent methods available for the determinations. 

International Council for the Exploration of the Sea (ICES). 1992. Report on the Results of the ICES/IOC/OSPARCOM Intercomparison Exercise on the Analysis of Chlorobiphenyl Congeners in Marine Media — Step 1 and the Intercomparison Study of the Determination of Cbs in Baltic Herring Oil. ICES Coop. Res. Rep. No. 183. 

The ability to make analytical measurements depends intimately on the availability of well-defined standards and calibrants. Many measurements of analytes in seawater (such as dissolved organic carbon and dissolved organic nitrogen) cannot be compared among laboratories because of the lack of appropriate reference materials and blanks for instrument calibration and testing. Intercomparison exercises are critical (NRC, 1993, p. 75). 

Multidimensional Data Intercomparisons. Estimation of reliable uncertainty intervals becomes quite complex for non-linear operations and for some of the more sophisticated multidimensional models. For this reason, "chemometric" validation, using common, carefully-constructed test data sets, is of increasing importance. Data evaluation intercomparison exercises are thus analogous to Standard Reference Material (SRM) laboratory intercomparisons, except that the final, data evaluation step of the chemical measurement process is being tested. 

An international intercomparison exercise in the determination of microcystin, carried out by using the most common methods (LC/DAD, ELISA and LC/MS) indicated that LC/DAD is affected by lower precision [234], while the coupling of the LC technique with ELISA permit the achievement of high sensitivity and specificity in the determination of microcystins and nodularin [235] without the need of pre-concentration the method meets the World Health Organization guidelines (1 pg L ). The combination of ELISA characterization and LC analysis with fluorescence, UV, and tandem MS detections, allowed the first identification of cylindrospermopsin, an algal toxin that caused the poisoning of up to 148 persons in Australia [236],... 

Volz-Thomas, A et al The PRICE (Peroxy Radical Intercomparison Exercise) An Introduction, Proc. XXIIUGG, 13263 (1995). 

Degueldre, C. (1990) Grimsel Colloid Exercise. An International Intercomparison Exercise on the Sampling and Characterization of Groundwater Colloids. EUR, EN 12660, CEC, Luxembourg. 

Sediment obtained from several sites in Lake Flumendosa, Italy, was collected, homogenised and, following a certification campaign, became available as BCR CRM 601 lake sediment certified for its extractable trace metal contents -sequential extraction (Quevauviller et d., 1997). In sediment CRM 601, concentrations of extractable Cd, Cr, Ni, Pb and Zn are certified in Step 1, but only Cd, Ni and Zn in Step 2, and Cd, Ni and Pb in Step 3. Indicative values are also given for extractable Cu in Step 1 and Pb in Step 2 (European Commission, 1997). The long-term stability of the extractable trace metal content of the reference material was recently demonstrated in a European intercomparison exercise (Lopez-Sanchez, 1998). 

In past years, on line chromatographic coupling techniques such as HPLC and CE coupled to ICP-MS with the isotope dilution technique have been used for element quantification in speciation analysis. An interesting application of the isotope dilution technique in medical research was proposed recently by Prange and co-workers, who added highly enriched " S, Cu, Zn and Cd spikes to the interface of the CE-ICP-MS system. The authors separated isoforms of metallothionein (e.g., of rabbit liver) by capillary electrophoresis and quantified S, Cd, Cu and Zn concentrations in isoforms by ICP-SFMS using the isotope dilution technique. A new selenized yeast reference material (SELM-1) for methionine, selenomethionine (SeMet) and total selenium content has also certified by an intercomparison exercise. ... 

An Efficient and Optimised Total Combustion Method for Total H-3 and C-14 6 INTERCOMPARISON EXERCISE RESULTS... 

GAU-Radioanalytical has participated in several intercomparison exercises for H-3 and C-14 activities in aqueous and biota samples. These results are in good agreement with the reference values (Table 4). Currently there are no commercially available natural matrix reference materials for total H-3 and therefore the analysis of spiked samples with known certified activities of H-3 is the best possible way of showing that the method is working. 

INDEPENDENT RADIOLOGICAL MONITORING RESULTS OF A RECENT INTERCOMPARISON EXERCISE... 

Independent Radiological Monitoring Results of a Recent Intercomparison Exercise 163... 

An intercomparison exercise or a proficiency test should be organised annually. The following matrices were proposed soil, water, vegetation and air filter which are of interest for routine monitoring and emergency situations. The analytical techniques that were recommended for inclusion in the proficiency tests are summarised in Table 1. 

It was recommended that the target values for each proficiency test should be released soon after the deadline for data submission for the world-wide test. It was also requested that other field intercomparison exercises (gamma does rate evaluation by in-situ gamma-spectrometry, sampling in aquatic systems, etc.) should be organized. 

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