Analysis of Cembranoids in Flue‐cured Tobacco by Accelerated Solvent Extraction and Gas Chromatography‐Mass Spectrometry‐Selected Ion Monitoring

An efficient and sensitive analytical method based on accelerated solvent extraction (ASE) and gas chromatography‐mass spectrometry‐selected ion monitoring (GC‐MS‐SIM) was developed and validated for analysis of cembranoids in flue‐cured tobacco leaves. Extraction efficiency of different pretreatment methods including liquid‐solid extraction (LSE), ultrasound‐assisted extraction (UAE), Soxlet extraction and accelerated solvent extraction (ASE) was compared and ASE was chosen as the optimal extraction method. During ASE procedure, effect of four parameters on extraction efficiency was considered and the experimental conditions were selected as follows: extraction solvent: dichloromethane; oven temperature: 50 °C; static time: 5 min and number of cycles: 2. Working standards of cembranoids were isolated by silica gel column chromatography and the identification was performed by mass spectrometry. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. The LOD and LOQ values were ranging from 5.0 × 10^?3 to 6.9 × 10^?3 μg/mL and 1.7 × 10^?2 to 2.3 × 10^?2 μg/mL for all analytes. At three different spiked levels, recoveries for CBT‐ol, α‐CBT‐diol and β‐CBT‐diol were 94.6%‐105.1%, 93.0%‐97.2% and 88.7%‐107.5% while the relative standard deviations (RSDs) were in the ranges of 3.9%‐6.2%, 1.8%‐8.7% and 1.7%‐6.0%, respectively. The proposed analytical methodology was successfully applied in the analysis of cembranoids in tobacco samples.