Differentiation between organic and inorganic chlorine by electrothermal vaporization inductively coupled plasma mass spectrometry: application to the determination of polychlorinated biphenyls in waste oils

Inductively coupled plasma mass spectrometry (ICP-MS) can be used as a screening test for chlorinated organic compounds such as polychlorinated biphenyls (PCBs) in oils. An upper limit for the PCB concentration can be deduced form the chlorine concentration. Owing to the contamination of oils with inorganic chlorine, a differentiation between ‘organic’ chlorine (PCB-chlorine) and inorganic chlorine is necessary. Electrothermal vaporization ICP-MS achieves this using a temperature programme having one step at 400 °C, for the vaporization of the PCBs, and a second at 2650 °C, for the vaporization of the inorganic chlorine compounds. The detection limits are between 0.5 and 10 µg of PCB per gram of oil depending on the nature of the oil and the degree of chlorination of the PCB.