Clean-up of organic seawater concentrates

The determination of PCCD/Fs usually involves extensive clean-up to remove coextracted compounds, typically present in greater amounts. The PCDD/Fs and the most toxic non-ortho chlorine substituted CBs (Nos. 77, 126 and 169) are planar molecules. They can be separated from bulk PCBs and other interfering compounds by chromatography on activated charcoal (Jensen and Sundstrom, 1974 Huckins etal., 1980 Smith, 1981 Kannan et al., 1991). The advantages of HPLC techniques on activated carbon (PX21) dispersed with n-octadecane (Cig) was shown by Kannan etal. (1993) Feltz et al. (1995) described an automated HPLC fractionation of PCDDs and related compounds. Modern clean-up procedures comprise HPLC on 2-(l-pyrenyl)ethyl dimethyl silylated silica (PYE) columns (Haglund et al., 1990 Kannan et al., 1998), a two-dimensional HPLC system for the separation of PCDD/Fs, PCB and PAHs (Zebiihr et al., 1993) and the automated HPLC method by Bandh 

Another current problem in environmental studies is the chromatographic separation of enantiomers of marine pollutants (Huhnerfuss and Kallenbom, 1992). HPLC with chiral stationary phases is a new tool to investigate the fate of chiral organic compounds and their degradation products in the environment Ludwig et al., 1992). 

The following is a detailed description of a clean-up procedure for seawater extracts (see also Chapters 18 and 22) into fractions of specific organochlorines, prior to gas chromatographic analysis with electron capture detection. Special attention is given to chlorobiphe-nyls (CBs). 

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