Analysis of cantharidin in false blister beetles (Coleoptera: Oedemeridae) by headspace solid-phase microextraction and gas chromatography–mass spectrometry

A headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrometry (GC–MS) method was developed to determine a type of terpenoid named as cantharidin in the false blister beetles, family Oedemeridae. The experimental parameters for HS-SPME method were optimized. Six commercial fibers for HS-SPME method development were tested and the divinylbenzene/carboxene/polydimethylsiloxane fiber was selected to provide the best detection of analyzed compound. The calibration curve showed linearity in the range of 0.1–50 μg mL−1, correlation coefficient (R2 = 0.992), limit of detection (0.01 ng mL−1) and quantitation (0.04 ng mL−1) were obtained for the proposed method. The relative standard deviations of intra-day and inter-day assays were 7.8 and 3.4%, respectively. The recovery values, obtained after spiking the beetle samples by three concentration levels of standard solution, were higher than 87%. The results indicated the successful application of the proposed method on the analysis of cantharidin from the false blister beetles.