Development of a solid-phase microextraction of halogenated volatiles in drinking water

The major class of volatile chlorination by-products in drinking water is that of trihalomethanes (THMs), which was also the first category of disinfection by-products identified in water . Besides THMs there also many other halogenated volatile compounds frequently occurring in drinking water, that have drawn significant scientific attention due to their potential adverse health effects on human beings. In order to protect public health from the possible carcinogen effects of these substances, the Italian law (D.Lgs. 2 feb. 2001 n. 31, referring to EU directive 98/83/EC) set specific limits to regulate the concentration of halogenated volatiles in drinking water. Therefore, determination of halogenated volatiles in drinking water is of importance and recently, researches have been orientated towards the development of inexpensive, simple and efficient sample preparation methods for the analysis of these compounds in aqueous samples. In this work is described the development of a simple and reliable method for trace analysis of THMs and other volatile compounds in water is performed by a concentration step by headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic separation with mass spectrometer detector (GC/MS). HS-SPME is a solvent-free process used for simultaneous extraction and pre-concentration of analytes from the headspace of the samples. The parameters including time of exposure of the fiber in the headspace, fiber type, agitation speed, ionic forces, temperature of adsorption, and time of desorption were evaluated. The procedure was applied to the analysis of 15 halogenated compounds in 22 drinking water samples coming from a municipal waterworks. Detection limit of 0.5 ng/L in water was achieved.