Fullerenes as sorbent materials for benzene, toluene, ethylbenzene, and xylene isomers preconcentration

A simple and novel SPE system for benzene, toluene, ethylbenzene, and xylene isomers (BTEX) compounds in water is proposed in which samples are directly propelled from a 15 ml, glass vial through a sorbent column by means of a needle, thereby avoiding evaporative losses and the sorption of BTEX on the manifold materials. Following elution with 150 mu l, of ethyl acetate, 1 mu L of extract is injected into a gas chromatograph-mass spectrometer system. A comparative study of various sorbent materials (C-60 fullerene, Tenax TA, and RP-C-18) revealed C-60 fullerene to be the best choice in terms of sensitivity (a likely result of its increased sample breakthrough volume), precision (the surfactant medium used to prepare samples minimizes evaporative losses), selectivity (C-60) fullerene only interacts with nonpolar aromatic compounds), and reusability (columns containing 60 mg Of C-60 fullerene remain serviceable for at least 6 months). This C-60 fullerene-based method exhibits a linear range of 0.1 - 100 mu g/L, a detection limit of 0.04 mu g/L, and an RSD of ca. 3%. It was applied to the determination of BTEX in various types of water including sea and waste water with good precision.