Analytical methods for dioxins and furans

Project coordinator: Dr. Dušan Žigon

Department of Environmental Sciences, Jožef Stefan Institute

The development of analytical procedures for furans and dioxins is part of the development of an incineration plant (support to the project “Thermal use of waste”), which will be used to control optimal conditions and evaluate the efficiency of new techniques.

Analysis of organic compounds in environmental samples in water, air or soil requires optimisation of each step of the analytical procedure: isolation, concentration, separation and identification of the organic compounds. In particular a suitable analytical procedure requires determination of extremely toxic dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/PCDF) in environment. The analytical method will be evaluated and implemented for determination of traces of PCDD/PCDF in emission products from the experimental incineration plant. An analytical method for PCDD/PCDF involves sampling, a cleanup procedure, extraction, addition of an internal standard, chromatographic separation and mass spectrometric detection and characterisation of isomeric polychlorinated compounds. The same analytical approach is required for control of emission products in the experimental waste incinerator plant where optimisation of all parameters in the combustion processes will be studied.

An analytical method based on high-resolution gas chromatography (HRGC), coupled to high resolution mass spectrometry (HRMS), provides an assay for determination of PCDD/PCDF in environmental samples at parts per billion (ppb) and potentially at low parts per trillion (ppt) levels. Mass spectrometry is the leading technique used in dioxin analysis for characterisation and quantification of different isomeric compounds of dioxins and furans. High resolution mass spectrometry allows quantitative detection of extremely low concentrations of organic pollutants in complex matrices of incinerator emission products.

The absolute instrumental sensitivity of a low resolution mass spectrometer (quadrupole mass spectrometer) is generally two orders of magnitude poorer than that achievable by a modern HRMS method. Following the recommendation by the Environmental protection agency (EPA) the HRMS method has emerged as the leading and routine analytical method for the determination of PCDD/PCDF at ppb and ppt levels in complex matrices. The ability to measure low concentrations of toxic organic compounds is required because of the extreme toxicity and proven carcinogenic behaviour of dioxins and furans.

The project comprises development and optimisation of the following procedures:

1.sampling of organic pollutants in stacks exhausts and in air in the vicinity of incinerators
2.pre-treatment and analytical treatment of complex samples
3.gas chromatographic separation
4.detection by mass spectrometry, identification, quantification