Evaluation of Laboratory Performance in IMEP Water Interlaboratory Comparisons

The aim of IMEP is to present objectively the quality of chemical measurements. Participants in IMEP compare their reported measurement results with independent external certified reference values with demonstrated traceability and uncertainty, as evaluated according to international guidelines. Three major Interlaboratory Comparisons, IMEP 6, IMEP 9 and IMEP 12, on trace elements in water were carried out from 1994 to 2000 in support to the council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption. Participants results for Cd, Fe and Pb amount content from these 3 different IMEP water ILCs were compared by means of suitable performance indicators. The performance evaluation criteria were set according to the requirements stated in the water Directive 96/83/EC. Two different performance indicators were selected for evaluation of the individual participants’ results: the commonly used z-score and the not so well-known En number. The group performance indicator was based on the variation of z-scores. To assess the individual measurement performance not only the deviation of the reported measurement values from the certified reference value, but also criteria for maximum, as set in the water directive, and minimum acceptable uncertainties were taken into account. As an example the participants’ performance is reviewed by means of using simple graphical tools, called “Naji-plots”.

BEDNAROVA Martina;  AREGBE Yetunde;  HARPER Caroline;  TAYLOR Philip; 

2006-04-04

SPRINGER VERLAG

JRC30966

https://publications.jrc.ec.europa.eu/repository/handle/JRC30966,   

10.1007/s00769-005-0031-6,