Thorough analysis of Iranian spearmint essential oil: combination of chemometrics and gas chromatography-mass spectrometry

Abstract

The components of Iranian spearmint essential oil were identified and quantified using gas chromatography-mass spectrometry (GC-MS) combined with chemometric tools. A multivariate curve resolution (MCR) approach was used to overcome the problems of background, baseline offset and overlapping/embedded peaks in GC-MS. The peaks were resolved using heuristic evolving latent projection (HELP) and multivariate curve resolution-alternating least squares (MCR-ALS) techniques. A new pure variable selection method named multivariate curve resolution-objective function equal to zero (MCR-FEQZ) is introduced and was applied in this work. The performance of this technique was evaluated and confirmed using MCR-ALS. The analysis of GC-MS data with the help of MCR techniques revealed that the five most abundant constituents of the Iranian spearmint essential oil are (+)-carvone (73.20%), limonen (14.63%), β-bourbonene (1.13%), cineole (1.10%) and 3-terpinolenone (0.82%). The results show that this essential oil could be a great source of carvone and limonene.