Evolution of the analytical techniques for PCDD/Fs, PBDD/Fs, and PXDD/Fs in air emissions: trends, applications and challenges

Chlorinated, brominated and mixed-halogenated dioxins and furans are of concern due to the high toxicity of their 2,3,7,8-substituted congeners. These can be released to the atmosphere from industrial processes involving high temperatures, organic matter and halogens. Their determination in matrices such as stack gases, ambient air and fly ash is challenging because they occur at trace levels within complex backgrounds, requiring highly sensitive and selective analytical methods. This review summarizes recent advances in their analysis in air samples, covering sampling, extraction, clean-up, and instrumental determination. Gas chromatography remains the primary separation method, while developments in mass spectrometric detection are highlighted. High-resolution magnetic sector mass spectrometry is still considered the gold standard, although instruments such as triple quadrupole, ion-trap, time-of-flight, and Orbitrap systems have shown growing applicability. The review also compiles current knowledge on emission sources, atmospheric concentration levels, and congener distribution patterns.