Biomonitoring of benzene and toluene in human blood by headspace-solid-phase microextraction

A simple and rapid method for the determination of benzene and toluene in w hole blood by headspace-solid-phase microextraction (HS-SPME) is described. Using SPME fibres coated with 65 mu m carboxene/polydimethylsiloxane, limi ts of quantification (LOQ) of 5 ng/L for benzene and 25 ng/L for toluene ar e achieved. As a result of its large linear range (i.e. 5-5000 ng/L for ben zene) the method is suitable for biomonitoring of both occupationally and e nvironmentally exposed people. The reproducibility of the determination of benzene is less than or equal to 8%. An interlaboratory comparison demonstr ated that the method proposed here compares favorably with existing methods (dynamic headspace, purge and trap).