Simultaneous determination of unmodified sevoflurane and of its metabolite hexafluoroisopropanol in urine by headspace sorptive extraction–thermal desorption–capillary gas chromatography–mass spectrometry

Unmodified sevoflurane and its metabolite, hexafluoroisopropanol (HFIP), have both been proposed as biomarkers of exposure in post-shift urine for operating room personnel exposed to inhalation anaesthetic sevoflurane. We used headspace sorptive extraction (HSSE) and thermal desorption–capillary GC–MS to assess sensitively both compounds in the urine matrix (after a HFIP deconjugation step). In GC–MS splitless mode, calibration plots (∼15–650 μg/L) were linear (r2 > 0.9910) and the limits of detection (1 μg/L for both biomarkers) showed increased sensitivity for HFIP with respect to the previously described headspace GC–MS method. The method was suitable for biological monitoring of both biomarkers of exposure to sevoflurane.