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), polychlorinated dibenzofurans (PCDFs), and a number of specific di-, mono-, and non-ortho, ortho'-chlorine (o,o'-Cl) substituted chlorobiphenyl congeners (PCBs) of toxicological significance from bulk PCBs and other interfering residues is critical for accurate quantitation of these compounds. 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 separative objectives. Our system produces four discrete fractions containing 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 with reduced requirements for manpower, and our system provides flexibility toward easy customization to meet specific analytical needs.