CHOOSING BETWEEN HIGH-RESOLUTION MASS-SPECTROMETRY AND MASS-SPECTROMETRY MASS-SPECTROMETRY - ENVIRONMENTAL APPLICATIONS

Selectivity in environmental analyses requires the use of fractionation techniques and HRMS or MS/MS to eliminate specific and nonspecific interferences. In the analysis of TCDDs and TCDFs, HRMS is the method of choice when specific interferences arising from compounds with molecular or fragment ions can be separated from TCDD and TCDF ions at a resolving power of 10000. In cases where HRMS does not provide adequate selectivity at this resolving power, MS/MS is needed. Analyses on a pulp and paper effluent extract show that MS/MS was able to substantially eliminate interferences due to the presence of methyl and ethyl tetrachlorinated dibenzofurans that were not removed by HRMS at resolving powers of 10000 and 18000. Nonspecific interferences may also be present due to coelution of compounds that cause changes in the response of the mass spectrometer and are best eliminated by fractionation techniques or by altering conditions of analyses. © 1990, American Chemical Society. All rights reserved.