ABSTRACT
The XAD-2 extracts were all analyzed by capillary column gas chromatography (GC) with electron capture detector. The tap water was passed through a large-volume XAD cartridge prior to the fortification to remove any polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) in the original water. The Florisil cleanup step is basically the same as that used in an earlier method for the determination of PCDD/PCDF in adipose tissue. Because of the toxicity and persistence of some isomers of PCDD and PCDF, methodology is required for the analysis of PCDD and PCDF at the parts-per-quadrillion (pg/L) level in water. To evaluate the technique for a wider range of PCDD/PCDF isomers, a solution of at least one isomer of tetra- to octa-PCDD and PCDF was prepared in acetonitrile for fortification purposes. The methods usually used for the analysis of chlorinated dioxins in water employ liquid/liquid solvent extraction with extensive cleanup of the extracts prior to instrumental analysis, usually by GC/mass spectrometry.
