3.2. Concentrations of the marker in methanolic leaves extracts
of tobacco
The GC–MS method applied is a modification of that reported by Stuart et al. for the analysis of nicotine present in tobacco. In the present study, a programmed method was used for simultaneous assay of the authentic marker nicotine. The standard was determined in a single GC–MS run. The standard was resolved and eluted at 10.16 min, with respect to nicotine
(Fig. 1). The marker showed a good linearity in the range from 5.0 to 1000 ng in the calibration curves that were obtained by GC–MS analysis. The reference marker was present in the chromatographic profiles of the samples from various locations when the sample solution was analyzed by GC–MS
(Fig. 2). The peak of nicotine was confirmed by comparison of the retention times with reference standard.