A porous graphitic carbon column (Hypercarb) was used for the fractionation of polychlorinated biphenyls (PCBs) into classes of 2-4 ortho chlorines, 1 ortho chlorine and 0 ortho chlorine congeners. A method was developed that combined the fractionation of PCBs, polychlorinated dibenzo-p-dioxins and dibenzofurans in a variety of biotic environmental samples. Many of these samples have high concentrations of PCBs which cause fractionation problems as adsorption sites on the graphitic surface are occupied. The loading capacity of the column for PCBs was determined by injecting up to 1 mg of total PCBs and monitoring changes in chromatographic behavior of tetra-/di-ortho, mono-ortho and non-ortho substituted PCBs. Effective loading capacities were 1 mg for tetra-/di-ortho PCBs, but only 3–5 μg for non-ortho PCBs and about 2 μg for mono-ortho PCBs. Loading capacity of the PGC column for environmental fish and avian egg samples was determined to depend on the mono-ortho and non-ortho PCB levels found in these samples.