The Handbook on PCB Congeners

PCB Groupings and Formulations

Toxicity and Abundance

PCB Congeners can be grouped according to their presence in the technical mixtures (i.e. Aroclors) and according to their toxicity, generally falling into the following pattern:

ConBrio704 Congeners that contain the fewer chlorine substitutions in the ortho positions are more toxic than those having more chlorines in those positions. The most toxic are the tetra, penta and hexachlorobiphenyl congeners that are unsubstituted in the ortho position.

Analytical Convenience

To obtain meaningful analytical data, the congeners need to be formulated into groupings of solutions that are all resolved on a gas chromatographic column. The “holy grail” of columns, the one column by which all 209 congeners are separated has, to this date, eluded all GC column manufacturers.

AccuStandard’s FT/IR, Mass Spectral data, melting point and chromatographic information along with chromatographic data from George Frame’s study is available in the book listed below:

There are 2 columns that are closest to achieving the “holy grail” status of separating all the PCB congeners. These two columns: Agilent DB-XLB & SGE’s HT 8 which resolve all but 4 pairs of significant congeners and 5 pairs of minor congeners.

George Frame and his co-workers at General Electric Company have coordinated a seminal study of specially formulated PCB groups - five of which are composed of the congeners contained in Aroclors, the remaining four mixtures contain those congeners generally absent in Aroclors. AccuStandard prepared and supplied the nine mixtures used in Dr. Frame’s study from its inventory of the 209 pure congeners.

These nine mixtures were then tested on 17 different columns by independent laboratories and column manufacturers. The resulting chromatographic retention time and response data was compiled and published (see reference 1). This information has proven invaluable for identification and quantification of the different Aroclors as well as for congener specific analysis.