Optimization of dioxin and furan analysis by HRGC-HRMS from different types of environmental matrices

Dioxins and furans analysis by HRGC-HRMS for determination of PCDD's and PCDF's
congeners enforce difficult preparation steps because of the possible presence of PCB's
congeners, PAH and other dioxin-like compounds . Standardizated methods like ISO 1948 and
EPA 8290 are very similar for air emissions, but in practice is a must to optimize every sample
preparation step. In this paper are presented the experimental results obtained for optimization
of the sample preparation steps which include the importance of humidity for XAD-2 adsorbent,
before and after sampling, timing of addition for sampling and extraction standards in the acid
treatment step, the critical role of purification adsorbents activation by temperature and even
the importance of concentration of the extract between sample preparation steps. The
instrumental parameters for the HRGC-HRMS, sample injection volume, chromatographic
separation, mass spectrometer resolution and sensitivity, were optimized to assure the
quantification of the PCDD and PCDF congeners, below national and international legislative
requirements. The method was verified by analyses of CRMs, fortified samples and real
samples of air emission, soil and sludge.