AUTOMATED HPLC FRACTIONATION OF PCDDS AND PGDFS AND PLANAR AND NONPLANAR PCBS ON C-18-DISPERSED PX-21 CARBON

The separation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlor inated dibenzofurans (PCDFs), and a number of specific di-, mono-, and non-ortho, ortho'-chlorine (o,o'-Cl) substituted chlorobiphenyl conge ners (PCBs) of toxicological significance from bulk PCBs and other int erfering residues is critical for accurate quantitation of these compo unds. Activated carbon has long been the most commonly used adsorbent for separation of these compounds into fractions suitable for analysis by capillary GC/ECD and by GC/MS. We have developed a procedure that uses HPLC columns containing PX-21 activated carbon dispersed by C-18 (octadecylsilane) sorbent in combination with an automated, quaternary HPLC autoinjector-fraction collector apparatus to attain these separa tive objectives. Our system produces four discrete fractions containin g bulk PCBs (di- to tetra-o,o'-chlorosubstituted); mono-o,o'-Cl PCBs; non-o,o'-Cl PCBs; and PCDDs/PCDFs. The fractionations are achieved wit h reduced requirements for manpower, and our system provides flexibili ty toward easy customization to meet specific analytical needs.