Polydimethylsiloxane/ionic liquid sponge used in headspace solid-phase extraction coupled with GC-MS for rapid analysis of essential oil in lavender

摘要

A headspace (HS) solid-phase extraction (SPE) based on polydimethylsiloxane (PDMS)/ionic liquid (IL) sponge was developed for the extraction of lavender essential oil. The PDMS after loading of 1-butyl-3-methylimidazolium tetrachloroferrate ([BMIM]FeCI_4) with a high surface area and excellent adsorption capacity was successfully applied in the SPE process. Microwave distillation (MD) coupled with HS-PDMS/[BMIM]FeCI_4 extraction after GC-MS was proposed. Various experimental parameters were studied. The optimal conditions were as follows: optimal IL, [BMIM] FeCI_4; volume ratio of IL to ethanol, 1:5; extraction solvent, n-hexane; microwave power, 600 W; and irradiation time, 12 min. The limits of detection and quantification of the analytic compounds were in the ranges 4.00-16.32 and 10.00-40.00 ng, respectively. The intra-day and inter-day precisions were in the ranges 0.37-1.94% and 1.20-2.45%, respectively. Under the optimized conditions, 13 samples of 3 lavender varieties were analyzed, and 40 compounds were identified. Lavender varieties were distinguished using principal component analysis. The results showed that MD-HS-PDMS/IL-GC-MS is a novel, simple, and sensitive method for the determination of essential oil in complex plant samples.