Analytical method for determination of allylic isoprenols in rat tissues by liquid chromatography/tandem mass spectrometry following chemical derivatization with 3-nitrophtalic anhydride

A liquid chromatography-tandem mass spectrometric (LC–MS/MS) method following chemical derivatization with 3-nitrophtalic anhydride was developed for the simultaneous determination of farnesol and geranylgeraniol in rat liver and testis. One analogue compound of the analytes, n-pentadecanol, was used as an internal standard (IS) for both analytes in this method. Rat tissues were disintegrated with 8% KOH ethanol solution, and then farnesol, geranylgeraniol and IS were extracted with a mixture of n-hexane–ethanol (98.5:1.5, v/v) in twice. Farnesol, geranylgeraniol and IS were then converted to 3-nitrophtalic derivatives of each analyte, and extracted with n-hexane. A turbo ion spray interface was used as the ionization source of LC–MS/MS and the analysis was performed in the multiple reaction monitoring (MRM) mode. The calibration curve at the spiked concentrations of 0.15–15 μg/g for both analytes showed good linearity. The method was precise; the relative standard deviations of the method for rat liver were not more than 13.4 and 5.4% for farnesol and geranylgeraniol, respectively, and those for rat testis were not more than 8.4 and 8.6% for farnesol and geranylgeraniol, respectively. The accuracies of the method for both rat liver and testis were good, with the deviations between the nominal concentration and calculated concentration of farnesol and geranylgeraniol typically being within 12.3 and 10.2%, respectively. This method provided reliable concentration levels for farnesol and geranylgeraniol in rat liver and testis.