- Journal Details
- First Published
- 01 Jan 1992
- Publication timeframe
- 4 times per year
- Open Access
Page range: 573 - 573
It is with sadness that we learned that T.C. Tso passed away in April of this year. In this issue of Beitraege, we publish an obituary written by Professor Lowell Bush on the personality and scientific career of Dr Tso.
T.C. Tso published 19 manuscripts in our journal. His first article in Beitraege was entitled “Examination of Aflatoxin B1 in Leaf Tobacco and in Cigarette Smoke Condensate” and published in 1967. His last article in Beitraege was a review entitled “Tobacco Research and Its Relevance to Science, Medicine and Industry” revealing a vision for the future of tobacco plant research. In a letter to the editor (Beitr. Tabakforsch Int. 23 (2008) 63-65), Hubert Klus appreciated this publication of Dr Tso in terms of its retrospective and prospective implications on tobacco-related science and science policy.
In this context, we would like to draw our readers’ attention to the autobiography of Dr Tso, which is mentioned in the obituary by Professor Bush. Finally, it should not go unmentioned that, for one decade - from 1988 to 1998, Dr Tso served as a member of the advisory board of our journal and helped to maintain the scientific standard of Beitraege.
- Open Access
Tien Chioh Tso, T.C. Tso, 1917-2013
Page range: 574 - 575
- Open Access
Quantitative Analysis of Humectants in Tobacco Products Using Gas Chromatography (GC) with Simultaneous Mass Spectrometry (MSD) and Flame Ionization Detection (FID)
Page range: 576 - 585
This paper describes the modification of an existing gas chromatographic (GC) method to incorporate simultaneous mass spectrometric (MSD) and flame ionization detection (FID) into the analysis of tobacco humectants. Glycerol, propylene glycol, and triethylene glycol were analyzed in tobacco labeled as roll-your-own (RYO), cigar, cigarette, moist snuff, and hookah tobacco. Tobacco was extracted in methanol containing 1,3-butanediol (internal standard), filtered, and separated on a 15 m megabore DB-Wax column. Post-column flow was distributed using a microfluidic splitter between the MSD and FID for simultaneous detection. The limits of detection for the FID detector were 0.5 μg/mL (propylene glycol and triethylene glycol) and 0.25 μg/mL (glycerol) with a linear range of 2-2000 μg/mL (propylene glycol and triethylene glycol) and 1-4000 μg/mL (glycerol). The limits of detection for the MSD detector were 2 μg/mL (propylene glycol and triethylene glycol) and 4 μg/mL (glycerol) with a linear range of 20-2000 μg/mL (propylene glycol and triethylene glycol) and 40-4000 μg/mL (glycerol). Significant improvement in the sensitivity of the MSD can be achieved by employing selective ion monitoring (SIM) detection mode. Although a high degree of correlation was observed between the results from FID and MSD analyses, marginal chromatographic resolution between glycerol and triethylene glycol limits the applicability of FID to samples containing low levels of both of these humectants. Utilizing MSD greatly improves the reliability of quantitative results because compensation for inadequate chromatographic resolution can be accomplished with mass selectivity in detection.
- Open Access
Characterisation of the Draw Resistance Across a Lit Cigarette
Page range: 586 - 594
The consumer senses and reacts to the draw resistance of the cigarette after it is lit. In spite of this obvious fact, this physical parameter is usually measured under standard conditions on the unlit cigarette (1). In order to evaluate more accurately the smokers’ perception during the course of cigarette smoking, the theoretical aspects of the draw resistance measurement of a lit cigarette have been studied and an experimental device has been developed.
During puffing on a smoking machine, the variation of the pressure in the cigarette holder is influenced by several parameters which are independent of the characteristics of the cigarette itself, such as the airflow and the experimental device characteristics. Theory and experiments show that the saturation of the Cambridge filter pad and the dead volume, in the sample holder and connection tubes, significantly modify the measured pressure at the mouth end. The impact of these modifications can be minimized by the calculation of a single parameter which is characteristic of the draw resistance of the cigarette, and derived from the evolution of pressure over time. In addition, the integration of the measured pressure profile during each puff provides another way for the draw resistance assessment and gives a value related to the energy required to generate each of them.
An experimental device has been developed using a oneport smoking machine, a cigarette holder with a connection for a pressure sensor, an analog-to-digital converter and a recorder. For the calibration of the system, a procedure using multi-capillary pressure drop standards composed of capillary tubes is discussed.
Finally, the developed device and approach enabled the measurement and the recording of the draw resistance evolution over the time as the cigarette burns, and thus a better assessment of the potential smokers’ sensation during smoking.
- Open Access
Roles of Tobacco Fractions in the Formation of Polycyclic Aromatic Amines in Tobacco Pyrolysis
Page range: 595 - 606
The aim of the present study was to gain further understanding of the precursors in tobacco of four polycyclic aromatic amines (PAAs) - 1- and 2-aminonaphthalene, 3- and 4-aminobiphenyl. We carried out non-isothermal pyrolysis of the residues, which were obtained after extraction of tobacco cut filler with methylene chloride followed by extraction with water, under three different pyrolysis conditions (target temperature 800 °C / 800 °C / 400 °C and O2 concentration in carrier gas 0% / 20% / 3%, resp.). The yields of the four PAAs obtained by the pyrolysis of each sample were evaluated. Several nitrogenous components in the sample were also analyzed. The results under all these pyrolysis conditions showed that 1) the methylene chloride-soluble fraction, in which 50-60% of nicotine was extracted, did NOT contribute significantly contribution to the yields of the four PAAs; 2) the watersoluble fraction, in which most of the nitrogenous inorganic ions and amino acids were extracted, contributed at an average of about 30% to total PAA yield; and 3) the insoluble residue, in which only protein was detected during the investigation of the nitrogenous components in the present study, showed the highest contribution, 50-60% of the four PAAs formed. Consequently, it is concluded that protein-like components in tobacco contribute highly to the formation of the four PAAs by tobacco pyrolysis.
- Open Access
Quantitative Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) Cited by the United States Food and Drug Administration
Page range: 607 - 616
The yields of 16 polycyclic aromatic hydrocarbons (PAHs) were determined from cigarette mainstream smoke condensate extracts using Gas Chromatography- Tandem Mass Spectrometry (GC-MS/MS). The method has been validated for ISO and Health Canada Intense (HCI) smoking protocols. Quantifiable levels (ISO means 0.16 to 365 ng/cig; HCI means 0.33 to 1595 ng/cig; n = 30) of 15 PAHs were found in the Kentucky reference cigarette K3R4F. The coefficient of variance (CV) was derived from ten determinations each run in triplicate. The CV range was 8.7% to 24.8% (ISO) and 6.6% to 24.3% (HCI). The limit of detection (LOD) based on empirical precision was ≤ 0.06 ng/cig (ISO) and ≤ 0.20 ng/cig (HCI) for all components except naphthalene (2.89 and 9.62 ng/cig, respectively). The yields from 5 unspecified branded cigarettes (Samples A-E) and 2 other reference cigarettes, K1R5F and the CORESTA monitor CM7, were determined under ISO smoking conditions. The same 15 PAHs were detected as in the K3R4F; however, cigarettes with lower yields of total particulate matter (TPM) were found to contain significantly less PAHs. One component was measured below the limit of quantification (LOQ) in Sample E and 2 components were < LOQ in the K1R5F.