Demands of effective PCDD/PCDF-analysis in environment and production control. Aims of an analytical laboratory to meet legal and toxicological requirements. Critical approach to detection limits

Attainable or obtained detection limits play an important role in the discussion of trace analysis of polychlorinated dibenzo-p-dioxins and -furans. Now-a-days state of the art is based as well on highly developed instrumental techniques as on sophisticated clean up methods. However, with this state of the art is not connected, necessarily, a defined level of detection limits. Comparison of detection limits obtained in various laboratories are difficult. Reasonable comparisons imply knowledge about definitions, ways of quantitation, strategies of improvement, their limitations, and the substances under investigations. Measures to improve detection limits and their limitations are interdependent in a complex manner. Examples are given in this presentation.

The group analysis of the degrees of chlorination of the dibenzo-p-dioxins and -furans deteriorates the detection limits with respect to the single isomer determitation because of the higher influence of the residual matrix. Particulary, these topics should be taken into consideration when planning and executing analytical work for regulatory enforcement and legal purposes.