doi:10.1016/j.chroma.2006.02.034
Copyright © 2006 Elsevier B.V. All rights reserved.
Characterization of essential oil components of Iranian geranium oil using gas chromatography–mass spectrometry combined with chemometric resolution techniques
Mehdi Jalali-Heravia,
,
, Behrooz Zekavata and Hassan Sereshtib
aDepartment of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran
bDepartment of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran
Received 5 December 2005;
revised 10 February 2006;
accepted 14 February 2006.
Available online 20 March 2006.
References and further reading may be available for this article. To view references and further reading you must
purchase this article.
Abstract
The essential oil components of geranium oil cultivated in center of Iran were identified and determined using gas chromatography–mass spectrometry data combined with the chemometric resolution techniques. A total of 61 components accounting for 91.51% were identified using similarity searches between the mass spectra and MS database. This number was extended to 85 components using chemometric techniques. Various chemometric methods such as morphological scores, simplified Borgen method (SBM) and fixed size moving window evolving factor analysis (FSMWEFA) were used for determining the number of components, pure variables, zero concentration and selective regions. Then the overlapping peak clusters were resolved into pure chromatograms and pure mass spectra using heuristic evolving latent projections (HELP) method. A characteristic feature of the Iranian geranium oil is the absence of 10-epi-γ-eudesmol in its constituents compared with the oil from northern and southern parts of India. The results of this work show that combination of hyphenated chromatographic methods and resolution techniques provide a complementary method for accurate analysis of essential oils.
Keywords: Geranium oil; Essential oil; Gas chromatography–mass spectrometry; Factor analysis; Resolution techniques
Fig. 1. Total ion current chromatogram of Iranian geranium oil.
Fig. 2. Total ion current chromatograms of peak clusters A, B and C.
Fig. 3. Morphological score plots for (a) peak cluster A; (b) peak cluster B; and (c) peak cluster C.
Fig. 4. FSWM plots of a–b, c–d and e–f for peak clusters A, B and C, respectively. Plots of a, c and e are obtained before correcting the heteroscedastic noise and b, d and f plots are due to after correction.
Fig. 5. Evolving latent projection graphs (ELPGs) of peak clusters A (a), B (b) and C (c). The straight lines 1 and 2 in (a) show the pure region of components 1 and 2 while curve 1 + 2 represents the overlapping region of components 1 and 2.The straight lines 1, 2 and 3 in (c) denote the pure regions of the three components in peak cluster BBB. Part (b) shows two straight lines 1 and 4 related to presence of two pure regions for the first and last components in peak cluster C, respectively.
Fig. 6. Resolved chromatograms of peak clusters A (a), B (b) and C (c).
Fig. 7. Resolved mass spectra and their counterpart standard mass spectra for peak clusters A, B and C. Resolved (a) and standard (b) mass spectra of 1,8-cineole; resolved (c) and standard (d) mass spectra of cis-ocimene; resolved (e) and standard (f) mass spectra of alpha-ylangene; resolved (g) and standard (h) mass spectra of trans-caryophyllene; resolved (i) and standard (j) mass spectra of citronellyl propionate; resolved (k) and standard (l) mass spectra of calarene; resolved (m) and standard (n) mass spectra of isoledene; resolved (o) and standard (p) mass spectra of alpha-muurolene; resolved (q) and standard (r) mass spectra of bicyclogermacrene.
Fig. 8. The mass chromatograms of purest m/z for peak cluster A, selected by simplified Borgen method (SBM) with κ = 0.1 and 0.75 when the number of components was set to be three.
Fig. 9. Borgen plot of peak cluster A.
Table 1.
Identity, retention time (R.T.), retention index (RI) and percentages of the components of Iranian geranium oil

Table 2.
Purest m/z founded by simplified Borgen method (SBM) for peak clusters A, B and C
