IJUP08 - Universidade do Porto

Development and validation of a new multiresidue method for the
determination of 17 polychlorinated dibenzodioxins (dioxins) and
polychlorinated dibenzofurans (furans) in environmental matrices
by SPME-GC-MS
A.Neves (1) , A.D. Guimarães (2) , M.F. Alpendurada (1,2)
4450-113 MATOSINHOS – Portugal
1) FFUP – Faculty of Pharmacy, University of Porto, Lab. of Hydrology / Rua Aníbal Cunha, 164-
4050-047 PORTO – Portugal
2) IAREN – Water Institute of the Northern Region / Rua Dr. Eduardo Torres, 229
4450-113 MATOSINHOS – Portugal
* Corresponding author: mfalpendurada@ff.up.pt
Polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are
persistent, highly lipophilic and toxic substances. These compounds are widespread in the
environment and occur mainly as secondary products of thermal processes involving such
as waste incineration, cement kilns firing hazardous waste, production of pulp using
elemental chlorine or several metallurgical industry processes. When released into aquatic
environments, PCDD/Fs become attached to organic particles which may be adsorbed on
suspended matter or even may sink down to the sediments. Eventually they tend to bio
accumulate through the food-chain which constitutes the main way of exposure to humans.
The harmful health effects of PCDD/Fs on men are evaluated by their action on a cellular
receptor, the Aryl Hydrocarbon Receptor (AhR) and include impairment of different
systems: immune system, nervous system, hormonal system as well as reproductive
functions. PCDD/Fs are also suspected of causing cancer.
Solid phase micro extraction coupled to capillary gas chromatography - ion trap mass
spectrometry (SPME-GC-MS) is presented as an alternative method to determinate 17
toxic PCDD/Fs. Sensitiveness, quickness, efficiency simplicity and low cost analysis are
some advantages of the designed method (1,2) . Global analytical method was optimized:
extraction step, chromatographic conditions and statistical parameters. Three different of
fibres were assayed: 100 µm, 7 µm, polydimethylsiloxane (PDMS) and 75 µm Carboxen-
PDMS fibers, and the best result for the majority of the compounds were obtained with 100
µm PDMS. Different extraction times (15, 30, 45, 60 min) and temperatures (70, 90,
100ºC) were studied.
The best results were obtained with 60 min of extraction at 90 ºC. Neither pH adjustment
nor ionic strength correction were necessaries to obtain good results, which enhances life
expectancy of SPME fibre and reduces sample handling Linearity, repeatability,
reproducibility, uncertainties, matrix effects, analytical sensitivity and influence of the
sample preparation protocol have been studied for method validation in agreement with the
international standard ISO/IEC 17025:2005.
Bibliographic references:
1-Fabrellas, B.; Sanz, P; Abad, E; Rivera,J.; Larrazábal, D.; Analysis of dioxins and furans in
environmental samples by GC-ion-trap MS/MS; Chemosphere, vol.55, 2004; 2-M:F:Alpendurada,
Solid-Phase micro-extraction: a promising technique for sample preparation in environmental
analysis, J. Chrom.A, 889 (2000) 3-14
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