Determination of tetrachlorodibenzo-p-dioxins by mass spectrometric metastable decomposition monitoring

A method of analysis of tetrachlorodlbenzo-p-dioxin (TCDD) has been developed In which the loss of COCI from the molecular ion is monitored. Because the reaction is anticlpated to be highly specific for TCDDs, the purified sample extracts were introduced in the mass spectrometer by using the direct Insertion probe instead of gas chromatography. The precisión, quality of calibration, and detection limit have been evaluated by analyzing standard solutions. Fifty plcograms of TCDD can be detected with a signal-to-noise ratio of 8:1. The accuracy and specificity have been tested by comparlng the results of this analysis with those using gas chromatography/high-res-olution mass spectrometry (GC/HRMS). Actual soll samples taken In the vicinity of a chemical Industry landfill were used. The specificity is comparable to the GC/HRMS method; how-ever, the accuracy Is not as good. The procedure Is appropriate for rapid Screening of purified sample extracts and for validating results from other analyses.