caa a22 4500 465748481 CHVBK 20180323111827.0 cr unu---uuuuu 170327e19900101xx s 000 0 eng 10.1007/BF00323024 doi (NATIONALLICENCE)springer-10.1007/BF00323024 Selection of reference methods for the determination of selenium in biological materials [Elektronische Daten] [K. Heydorn, B. Griepink] Summary: Over the period 1985-1989 the European Community Bureau of Reference (BCR) has certified 7 biological reference materials for selenium with concentrations ranging from 0.03 to 10 mg/kg. Certification analyses were carried out by the most experienced laboratories in the Member States, using Fluorimetry, Hydride formation, combined with ICP or AAS, Electrothermal AAS with or without Zeeman-background correction, Instrumental or radiochemical NAA. Results from these exercises are available in a form suitable for estimating the experimental precision of the various methods as a function of concentration. With the same number of replicates for all analyses the logarithm of the observed standard deviations have constant variance, independent of concentration; for each method the absolute and relative standard deviations can therefore be estimated by means of non-linear regression. Analytical bias was monitored plotting results and their estimated standard deviations from individual laboratories versus certified confidence intervals. For concentrations of Se <0.3 mg/kg fluorimetry was selected as a reference method; above this level INAA is recommended; both are capable of producing unbiased results. Springer-Verlag, 1990 Heydorn K. Risø National Laboratory, DK-4000, Roskilde, Denmark aut Griepink B. Community Bureau of Reference, B-1049, Brussels, Belgium aut Fresenius' Journal of Analytical Chemistry Springer-Verlag 338/3(1990-01-01), 287-292 0937-0633 338:3<287 1990 338 216 https://doi.org/10.1007/BF00323024 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00323024 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heydorn K. Risø National Laboratory, DK-4000, Roskilde, Denmark aut NATIONALLICENCE 700 1- Griepink B. Community Bureau of Reference, B-1049, Brussels, Belgium aut NATIONALLICENCE 773 0- Fresenius' Journal of Analytical Chemistry Springer-Verlag 338/3(1990-01-01), 287-292 0937-0633 338:3<287 1990 338 216 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer