Separation and quantitation of 3,3',4,4'-tetrachlorobiphenyl and 3,3',4,4',5,5'-hexachlorobiphenyl in aroclors using florisil column chromatography and gas-liquid-chromatography
Kamops, LR; Trotter, WJ; Young, SJ; Smith, AC; Roach, JAG; Page, SW
Florisil column chromatography and gas/liquid chromatography with mass spectrometry were used for separation and analysis of polychlorinated biphenyls in various Aroclor solutions. Chromatographic analysis on a Florisil column with Aroclor standard solutions yielded elution of about 95 percent of the polychlorinated-biphenyls (PCBs) in Fraction-A. However, 3,3',4,4'-tetrachlorobiphenyl (32598133) (TCB) and 3,3',4,4',5,5'-hexachlorobiphenyl (32774166) (HCB) eluted mostly in Fraction-B, with respective average recoveries of 81 and 67 percent. The authors suggest that greater Florisil binding of these PCBs is due to the fact that these molecules present greater and more polarizable pi electron densities for adsorbent interaction than do most ortho substituted PCBs, which are less planar in nature. Analyses for TCB and HCB were performed by electron capture/gas liquid chromatography using a capillary and a packed column, respectively. The limits of detection were both about 200 parts per million for the amounts of Aroclors analyzed. The highest level of TCB in the Aroclors tested was found in Aroclor-1248 (12672296). Syntheses and gas chromatographic analyses of 3,3',5,5'-tetrachlorobiphenyl, 3,3',4,5'-tetrachlorobiphenyl and TCB were carried out to eliminate the possibility that the TCB congener in an Aroclor eluting at the gas liquid chromatographic retention time of the TCB reference standard might be a 3,3',5,5' or 3,3',4,5'congener. Both 3,3',5,5' and 3,3',4,5'congeners were readily resolvable from the component eluting at the retention time of TCB.
