Resumo

VALLEJO-VARGAS, Olga I et al. Determination of trihalomethanes in drinking water by solid phase microextraction- gas chromatography in Pereira, Colombia. Rev.Colomb.Quim. [online]. 2015, vol.44, n.1, pp.23-29. ISSN 0120-2804.  https://doi.org/10.15446/rev.colomb.quim.v44n1.54041.

Water disinfection with chlorine generates byproducts such as trihalomethanes (THM's), to which cancer risk and a potential adverse effect on the reproductive system properties are attributed. The maximum permitted level of THM's in the United States is 80-100 µg/L, while in Colombia it is 200 µg/L. In this study a simple, fast and solvent-free method was developed for the determination of THM's in drinking water using solid phase microextraction in combination with head space gas chromatography microcapture electron detector (HS-SPME-GC-µECD) and used for quantification of THM's in drinking water. Experimental parameters such as extraction time, extraction temperature, desorption temperature, magnetic stirring, and addition of salt were studied. Limits of detection and quantification were determined and the analysis of THM´s in 75 samples of water from the treatment plant of Pereira city were performed. Optimized conditions were 20 min extraction at 37 °C in the presence of 25% NaCl and with stirring at 200 rpm; with a desorption time of 4 min at 250 °C. Linear range of 5-100 µg/L was established with a relative standard deviation (% RSD) in the range 6.1-10.1%. Detection limits ranged from 3.8 to 7.8 µg/L. Average concentration of THMs was 55.5 µg/L which was within International and National requirements.

Palavras-chave : Trihalomethanes; headspace-solid-phase microextraction; gas chromatography; drinking water; lectrons microcapture.

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