High-resolution mass spectrometric determination of polychlorinated dibenzo-P-dioxins and dibenzofurans using an alternative lockmass system

A high-resolution mass spectrometric selected ion monitoring (HRMS-SIM) methodology for the analysis of all tetra-through octachlorinated dibenzo-p-dioxins (Cl/sub x/DD, x = 4-8) and dibenzofurans (Cl/sub x/DF, x = 4-8) utilizing an alternative lockmass system has been developed at the Ministry of the Environment (MOE). Incorporation of the MOE lockmass system gives an enhancement in sensitivity, easier control of the lockmass concentration in the ion source, and greater resolution between the lockmass and the sample ion signals than dose the conventional perfluorokerosene (PFK) lockmass system. In addition, the method can be adapted to any sector instrument having a similar lockmass facility and to any HRMS-SIM analysis with the appropriate choice of reference standards. A comparison of the MOE and PFK systems is reported.