| Abstract
| - A solid phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS)method was developed to assess actual doses of highly reactive organic compounds like styreneoxide (SO) in exposed cell cultures. Using SPME, we set up a method to measure accuratelyextracellular SO concentrations as well as to obtain an approximate assessment of intracellularlevels. The SPME−GC/MS method was developed and validated using two different coatingmaterials, carboxen-PDMS and polyacrylate. In cell-free systems, linearity was establishedover 3 orders of magnitude for both fibers, but carboxen-PDMS showed higher extractionefficiency and a lower limit of detection (0.5 × 10-7 vs 10-6 M for polyacrylate). Precisioncalculated as % RSD was within 4−16% for all intra- and interday determinations. Experimentsperformed to study SO stability in cell-free medium showed a time-dependent decrease in SOconcentration (11% of initial the concentration after 24 h), mostly due to the spontaneoushydrolysis of SO into styrene glycol, which was measured by liquid chromatography/tandemmass spectrometry (LC/MS/MS). When the neuronal cell line (SK-N-MC) was exposed to anominal concentration of 0.3 × 10-4 M SO, the actual concentration measured in thesupernatant was considerably lower and was found to decrease during incubation. IntracellularSO was estimated indirectly, by difference between the amount measured in the mediumwithout cells and in the supernatant of the cell-containing medium.
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