Title: Comparison of CALUX-TEQs and levels of PCDD/F and PCB in SFE-extracts of human adipose tissue

Auteur(s): Olsman H ; Engwall M ; Van Bavel B ; Bjornfoth H ; Lindstrom G ;  ; 

Year: 2003

Journal: Organohalogen Compounds

Subject(s): CALUX ; PCB ; PCDD/F ; dioxin ; bioassay ; analysis ; extraction ; clean-up ; Ah receptor ; TEQ ; dioxin-like compounds ;  ; 

Summary: Dioxin bioassays have been used as an alternative and complement to conventional high resolution gas chromatography/mass spectrometer (HRGCIMS) analysis of human samples in epidemiological studies. Dioxin bioassays are sensitive and cheaper than chemical analysis, enabling larger numbers of samples to be run. These conditions make dioxin bioassays like the CALUX well suited to conduct large-scale epidemiological studies. However, even though the analysis in itself is time effective, the extraction and clean up is still throughput limiting, and the choise of clean up method may be very crucial for the results obtained. Presence of Ah receptor (AhR) interacting and inhibiting compounds in a sample subject to bioassay analysis will obstruct the interpretation of results and may lead to under- or overestimation ofTEQS3,4. One way to estimate TEQ content by bioanalytical methods more appropriately, is to separate compounds of interest by chemical fractionation of samples. In order to improve throughput capacity, new extraction techniques with automation possibilities and decreased time and solvent consumption have been developed for analysis ofPCDD/Fs. The mostly used extraction techniques like Soxhlet often use large solvent volumes and require long extraction times. The supercritical fluid extraction technique (SFE) has seen an increased interest as an environmental friendly sample preparation technique and it is now well established as a technique with short extraction times and minimal usage of organic solvents for chemical analysis. The use of the CALUX bioassay in combination with the rapid and automated SFE-LC extraction and fractionation technique to screen large numbers of human samples holds promise for future epidemiological studies. In this study, we have tested the applicability of this combination of techniques on planar and non-planar fractions of human adipose tissue samples. We tested the two fractions separately and together, to test the assumption of additive effects of dioxin-like compounds. In addition, we have compared the CALUX TEQs levels with PCB and PCDD/F measurements, expressed as WHO-TEQs and TEQs (i.e. TEQs calculated using CALUX-specific relative potency values).