Results of proficiency testing for determination of dioxins in fly-ash (1st round) based on ISO/IEC Guide 43-1

Abstract

The Japan Society for Analytical Chemistry carried out proficiency testing on the determination of dioxins (polychlorodibenzo-p-dioxins, polychlorodibenzofurans and coplanar polychlorobiphenyls) in fly-ash of a waste incinerator. The proficiency testing of analytical laboratories is based on ISO/IEC Guide 43-1 "Proficiency testing by interlaboratory comparisons". This testing was carried out from November 2000 to March 2001, with the participation of 41 laboratories. The test results were; 0.987 ng-TEQ/g of total dioxin concentration on the average, 13% in robust standard deviation. Two labs were judged to be unsatisfactory because of their large z-score in the robust method (over 3 in absolute value).