Determination of perfluorodecalin and perfluoro-N-methylcyclohexylpiperidine in rat blood by gas chromatography-mass spectrometry

A gas chromatography-mass spectrometry method (SIM mode) was developed for the determination of perfluorodecalin (cis and trans isomers, 50% each) (FD C), and perfluoromethylcyclohexylpiperidine (3 isomers) (FMCP) in rat blood . The chromatographic separation was performed by injection in the split mo de using a CP-select 624 CB capillary column. Analysis was performed by ele ctronic impact ionization. The ions m/z 293 and m/z 181 were selected to qu antify FDC and FMCP due to their abundance and to their specificity, respec tively. The ion m/z 295 was selected to monitor internal standard. Before e xtraction, blood samples were stored at -30 degrees C for at least 24 h in order to break the emulsion. The sample preparation procedure involved samp le clean-up by liquid-liquid extraction. The bis(F-butyI)ethene was used as the internal standard. For each perfluorochemical compound multiple peaks were observed. The observed retention times were 1.78 and 1.87 min for FDC, and 2.28, 2.34, 2.48 and 2.56 min for FMCP. For each compound, two calibra tion curves were used; assays showed good linearity in the range 0.0195-0.7 8 and 0.78-7.8 mg/ml for FDC, and 0.00975-0.39 and 9.39-3.9 mg/ml for FMCP. Recoveries were 90 and 82% for the two compounds, respectively with a coef ficient of variation <8%. Precision ranged from 0.07 to 15.6%, and accuracy was between 89.5 and 111.4%. The limits of quantification were 13 and 9 mu g/ml for FDC and FMCP, respectively. This method has been used to determin e the pharmacokinetic profile of these two perfluorochemical compounds in b lood following administration of 1.3 g of FDC and 0.65 g of FMCP per kg bod y weight, in emulsion form, in rat. (C) 2000 Elsevier Science B.V. All righ ts reserved.