Elution order of the 209 polychlorinated biphenyls on a high-temperature capillary column

Abstract

Retention times of the 209 polychlorinated biphenyls (PCBs) were determined by gas chromatography in combination with electron ionization mass spectrometry on a newly developed stationary phase which was suitable to 380°C. The so-called Thermocap A phase consisted of 50% methyl–50% phenyl polysiloxane which was prepared by using an in situ process. On Thermocap A, the sum of the McReynolds constants was five times lower than on conventional equimolar methyl–phenyl phases distributed with the tradenames CP-Sil 24 or DB-17. The Thermocap A column showed some unique elution orders of PCB congeners. For example, PCB 133 eluted in front of PCB 136 which was not reported on any other stationary phase before. Most of the PCB congeners which are part of national regulations in Europe eluted without interference from the Thermocap A phase. The changed elution order and the high-temperature stability recommends the use of the Thermocap A phase for PCB analyses alone or as a confirmatory column.