Headspace gas chromatography-mass spectrometry in the analysis of lavender’s essential oil: Optimization by response surface methodology

•A HS–GC/MS method was developed to study the volatile content of lavender’s essential oils.•Experimental design (DοE) applied provided optimum HS injection system parameters.•A comprehensive profile of the EO volatiles can be obtained.•Rich informative aromatic profiles can aid lavender’s EO characterization. A static headspace gas chromatography - mass spectrometry (HS–GC/MS) method was developed and optimized with the aim to be applied in the analysis of lavender essential oil. To obtain a comprehensive profile of the essential oil, the optimum HS–GC/MS method parameters were selected based on a Design of Experiments (DοE) process. Plackett-Burman experimental design was applied by utilizing seven parameters of the HS injection system. Incubation equilibration temperature and time, agitator’s vortex speed, post injection dwell time, inlet temperature, split ratio and injection flow rate were screened to select the optimum conditions on the basis of the number and the intensity of the identified compounds. Other parameters, such as sample volume and dilution solvent ratio, were also examined to achieve a comprehensive profile in a chromatographic run of 55 min. With the obtained optimum method, more than 40 volatile compounds were identified in lavender’s essential oils from different geographical regions in Greece. The method can be utilized for the quality assessment of lavender’s essential oil and provide information on its characteristic aroma and discrimination among species based on the acquired GC–MS profiles.