Study of thermal decomposition at a GC injector in an analysis of PBDDs/PBDFs by high-resolution GC/MS

Abstract

It is believed that PBDD/Fs will cause a big environmental problem, just as PCDD/Fs, in the near future. Therefore, the establishment of an analytical method for PBDD/Fs is very important and urgently necessary. However, information regarding this matter is insufficient. We examined the thermal-decomposition reaction of PBDD/Fs by a measurement using a high-resolution GC/MS method involving splitless injection. As a result, debrominated compounds of PBDD/Fs were detected in all temperature ranges for sufficient vaporization efficiency at the time of splittless injection. It is beleived that these debrominated compounds are the thermal-decomposition products produced by a momentary vaporization during injection, based on information from the mass spectra, the GC retention times and the peak shape of the chromatogram peaks. However, it was confirmed that the thermal decomposition was different between the different systems in the same setup, as well as on the same condition. It was thus found that thermal decomposition occurred remarkably when an element of the stainless-steel metal origin, such as nickel and cobalt, was made to exist together in the injector. We suppose that a difference in the delicate environment inside the injector greatly influences the thermal decomposition of PBDD/Fs. Therefore, it is necessary to confirm the thermal decomposition at first when a measurement of PBDD/Fs with high-resolution GC/MS is carried out.