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(T/EH109) Screening of organic contaminants in industrial efluents by Solid Phase Microextraction/Gas Chromatography-Mass Spectrometry. Alonso, C.1, Fernandez, C.1, Tarazona, J.V.1, 1 ABSTRACT- Among the huge number of contaminants present in the surface waters only a small percentage of them are identified. Characterisation of so complex mixtures of organic compounds is not an easy task. One of the difficulties affecting this objective is to discriminate among substances present in the matrix at enormously different ranges of concentration. Information on the industrial processes is obviously useful but not conclusive. Previous studies showed that about one half of the effluents contained chemicals not included in the list of contaminants selected according to the description of the industrial processes conducted at the facility. A screening protocol was designed for routine analysis. The liq-liq n-hexane extract was analysed by GC-MS in EI mode using a non polar chromatographic column running from a very low (40°C) to a high (275°C) temperature registering the mass spectra in SCAN mode (40-600 m/z). The commercialisation of solid phase microextraction fibres offers additional possibilities. This work compares the extraction capacity of the liq-liq extraction procedure and SPME fibres, with direct fibre desorption at the chromatograph injector, under similar gas chromatographic conditions. Four SPME fibres, Red, White, Light blue, and Yellow-green, from SUPELCO were employed. The comparison of the chromatograms clearly showed the increase of response of the SPME versus the Liq-Liq extraction for the majority of compounds detected. Differences among fibres were also observed, but all of them showed better sensitivity than the Liq-Liq extraction. In addition, the SPME/GC-MS chromatograms showed several peaks not detected in the Liq-Liq extracts. It is concluded that the microextraction procedure offers an excellent opportunity for the screening analysis of complex mixtures including industrial effluents. Key words: solid phase micro extraction, gas chromatography-mas spectrometry, organic contaminant, industrial effluents |
