Discrimination of three tobacco types (Burley, Virginia and Oriental) by pyrolysis single-photon ionisation?time-of-flight mass spectrometry and advanced statistical methods

Abstract

Pyrolysis single-photon ionisation (SPI)-time-of-flight mass spectrometry (TOFMS) and statistical analysis techniques have been applied to differentiate three major tobacco types, Burley, Virginia and Oriental, by means of the gas phase. SPI is known as a soft ionisation technique that allows fast and comprehensive on-line monitoring of a large variety of aliphatic and aromatic substances without fragmentation of the molecule ions. The tobacco samples were pyrolysed at 800 degrees C in a nitrogen atmosphere. The resulting pyrolysis gas contained signals from more than 70 masses between m/z 5 and 170. Mass spectra obtained were analysed by principal component analysis (PCA) and linear discriminant analysis (LDA) to distinguish between different tobacco types. Prior variable reduction of the data set was carried out by calculation of the Fisher ratios. Results achieved give information about chemical composition and characteristics of the smoke derived from each tobacco type and enable conclusions on plant cultivation to be drawn. Based on LDA, a model for tobacco type recognition of unknown samples was established, which was cross-checked by additional measurements of each tobacco type. Furthermore, first results on the recognition of tobacco mixtures based on principal component regression (PCR) are presented.

Pyrolysis and combustion of tobacco in a cigarette smoking simulator under air and nitrogen atmosphere

“…Since tobacco smoke is a complex and reactive matrix containing over 5,600 identified compounds in vapour and particle phases [11,24,25], unravelling mechanistic information in real time requires a fast analysis technique. Time-of-flight mass spectrometry combined with photo ionisation has been proven to be capable of analysing cigarette smoke and other complex gas mixtures online with a high time resolution [10,[26][27][28][29][30][31][32][33][34][35]. Various volatile organic compounds covering a wide dynamic range of concentrations can be detected.…”

“…acetaldehyde). The detection of bulk matrix compounds present in the combustion atmosphere such as nitrogen, oxygen, water and carbon dioxide is suppressed due to their ionisation potentials exceeding the energy of the laser-generated VUV-photons [10,28].…”

Electron spin resonance study of puff-resolved free radical formation in mainstream cigarette smoke

“…1,2 Although the dynamic and reactive nature of cigarette smoke is recognized, it is only recently that studies based on fast mass spectrometers and laser-based techniques have begun to unravel the extent of formation of transient smoke species. [3][4][5][6][7][8][9][10][11][12][13][14] Routine smoke analysis methods used in the tobacco industry are usually developed to quantify the total yields of smoke constituents after the entire cigarette is machine-smoked under a standard puffing regime. To provide the accuracy and sensitivity required for puff-resolved analysis, fast analytical techniques are needed.…”

“…[3][4][5][6][7] Thus, in addition to the gradual increase in the 'tar' yields with puff number, some other trends have also been observed. [7][8][9][10] For example, it has been shown that, for some vapour phase smoke components (e.g., formaldehyde and 1,3-butadiene), the yields for the first puff are much higher than for the subsequent puffs and can account for over 30 to 40% of the total yields. [11][12][13][14] This phenomenon may be related to the fact that the tobacco consumed in the 1 st puff is heated from room temperature, while for later puffs the tobacco is pre-heated by the advancing smouldering coal.…”

“…3 Different lighting methods can also affect the yields in the first puff. [3][4][5][6][7][8][9][10][11][12][13] It is well known that free radicals in cigarette smoke contain both short-lived gas phase radicals and persistent particulate phase radicals. [15][16][17] Using electron spin resonance (ESR) spectroscopy, it is possible to quantify as well as identify the radical species involved.…”