Organochlorine and heavy metal residues in harbour seals from the wadden sea and their possible effects on reproduction

Trace analysis of pesticides by gas chromatography

Toxicokinetics in fish: Accumulation and elimination of six chlorobenzenes by guppies

Three institutes worked together on the development and improvement of methods for the analysis of polybrominated diphenylethers (PBDEs) in sediments and biota. The methods developed consist of a Soxhlet, Ultra Turrax* (biota) or shake-flask extraction (sediment) using hexane (or pentane)/acetone solvent mixtures, clean-up by alumina column chromatography or by gel permeation chromatography, further clean-up by silica gel column chromatography and treatment with sulphuric acid. Several alternatives for extraction and clean-up yielded similar results. The final determination is performed by GC/NCI-MS in the selected ion mode with m/z values of both Br isotopes (79 and 81 occurring in a 1:1 ratio). For decaBDE the fragments m/z 486.7 and 488.7 were also scanned. The coefficients of variation obtained with this method are between 10 and 35% for individual congeners, and comply at least with the international state-of-the-art for this type of analysis.

K. Marsden

Papers

Single-stage clean-up of animal tissue extracts for organochlorine residue analysis.