Qualitative and quantitative determination of PCB congeners by using a HT-5 GC column and an efficient quadrupole MS

Abstract

The determination of CB congeners by means of a new HT-5 column (SGE Australia) was carried out with a quadrupole GC-MS. A method is presented that permits the qualitative and quantitative determination of environmental and technical PCB mixtures with the help of only 14 single CBs, 2–4 reference CBs per degree of chlorination in SIM mode. More than 70 individual CBs, including some coplanar congeners such as CB-77, CB-126 and CB-169, were measured as pure standards. Additionally Clophen A30/A40/A60 and Aroclor 1254 1260 were measured. With our method a total of 131 single CBs could be identified. For the quantitative determination several PCB congener groups were formed for each level of chlorination according to their fragmentation pattern. One CB with group-typical fragmentation was used as reference for the calibration within the group. The fragmentation pattern is strongly correlated with the molecular structure of the single CB, so that CBs not available as pure standards can be identified. Some remarkable correlations between structure of CBs of all degrees of chlorination and their fragmentation in MS EI-mode were discovered. A similar retention time does not mean a similar fragmentation pattern of these CBs and vice versa. The measurements were carried out in scan mode measuring masses 100–650 and in SIM-mode, considering the [M] +, [MCL] + and [M2Cl] + ions.