Solid phase microextraction of volatile organic compounds using carboxen-polydimethylsiloxane fibers

A new 80 mu m Carboxen-polydimethylsiloxane (PDMS) fiber for solid phase microextraction (SPME) was tested for the enrichment of volatile organic compounds from water and air. Detection limits between 13 ng L-1 (CH2Cl2) and 0.1 ng L-1 (CHCl2Br and CHClBr2) for the combination: Carboxen-PDMS fiber and GC-ECD and between 35 ng L-1 and 45 ng L-1 (BTEX compounds) for the combination: Carboxen-PDMS and GC-FID using the headspace procedure were determined. Comparisons with the 100 mu m PDMS fiber and further coatings show the advantages of the Carboxen-PDMS fiber with respect to extraction efficiency. Disadvantages of the new fiber compared with the 100 mu m PDMS fiber are poorer repeatability and prolongation of equilibrium time. Distribution coefficients of the BTEX compounds between aqueous solution and SPME fiber coating were calculated and compared with the results of other researchers and with octanol-water partition coefficients.