Rapid and simplified method for the analysis of polychloronaphthalene congener distributions in environmental and human samples by gas chromatography coupled to negative ion chemical ionization mass spectrometry

A method for the analysis of congener-specific polychloronaphthalene mixtures in sediments and human sera based on combined applications of gas chromatography coupled to negative ion chemical ionization mass spectrometry (GC–NICI-MS) is described. Separation, identification and quantification of the constituent congeners is achieved in both types of samples. Besides the octa- and heptachloronaphthalenes the method allows the identification of 9 hexachloronaphthalene congeners, 12 pentachloronaphthalenes and 8 tetrachloronaphthalenes. Detection and quantification limits were in the order of 0.4–0.7 ng g−1 dry weight and 0.9–1.3 ng g−1 dry weight in sediments, respectively, and 0.06–0.11 ng mL−1 and 0.18–0.21 ng mL−1 in human sera, respectively. Application of the method to study the distributions of these compounds nearby a chlor-alkali plant located at the shore of the Ebro River has shown that whereas the most chlorinated compounds, octachloronaphthalene and the two heptachloronaphthalenes were dominant in the sediments, tri-, tetra-, penta- and hexachloronaphthalenes were the most abundant congeners found in human sera.