Amparo Gómez-Siurana

Comparative study of the main characteristics and composition of the mainstream smoke of ten cigarette brands sold in Spain.

In this study 10 commercial top selling cigarette brands in Spain have been machine smoked and the mainstream smoke has been analyzed. Multifunctional analysis has been satisfactorily employed to correlate the effect of the main design features of the cigarettes including amount of tobacco, filter size or paper weight with the amount of smoked tobacco and with the ratio CO(2)/CO. The composition of the vapor phase and that of the particulate matter have been analyzed. The particulate matter retained in the filter of the cigarettes has also been analyzed showing a distinct behavior of the compounds condensed in the cigarette filters and in the traps, related to their retention time. A general trend for the relative yield of some compounds in the different brands have been identified and confirmed by multifunctional analysis. Nevertheless, there are some noticeable compounds that behave differently in the different brands.

Reduction of tobacco smoke components yield in commercial cigarette brands by addition of HUSY, NaY and Al-MCM-41 to the cigarette rod

The effect of two zeolites, HUSY, NaY and a mesoporous synthesized Al-MCM-41 material on the smoke composition of ten commercial cigarettes brands has been studied. Cigarettes were prepared by mixing the tobacco with the three powdered materials, and the smoke obtained under the ISO conditions was analyzed. Up to 32 compounds were identified and quantified in the gas fraction and 80 in the total particulate matter (TPM) condensed in the cigarettes filters and in the traps located after the mouth end of the cigarettes. Al-MCM-41 is by far the best additive, providing the highest reductions of the yield for most compounds and brands analyzed. A positive correlation was observed among the TPM and nicotine yields with the reduction obtained in nicotine, CO, and most compounds with the three additives. The amount of ashes in additive free basis increases due to the coke deposited on the solids, especially with Al-MCM-41. Nicotine is reduced with Al-MCM-41 by an average of 34.4% for the brands studied (49.5% for the brand where the major reduction was obtained and 18.5 for the brand behaving the worst). CO is reduced by an average of 18.6% (ranging from 10.3 to 35.2% in the different brands).

Comparison between the mainstream smoke of eleven RYO tobacco brands and the reference tobacco 3R4F

In this study 11 commercial roll-your-own (RYO) tobacco brands sold in Spain and the reference tobacco 3R4F have been smoked and several components of the mainstream tobacco smoke have been analyzed. Cigarettes were prepared using commercial tubes, and were smoked under smoking conditions based on the ISO 3308. The gaseous and condensed fractions of the smoke from RYO brands and 3R4F have been analyzed and compared. RYO tobaccos, as opposed to 3R4F, present lower amounts of condensed products in the traps than in the filters. In general, RYO tobaccos also provide lower yields of most of the compounds detected in the gas fraction. The yield of CO is between 15.4 and 20.4 mg/cigarette. In most of the cases studied, RYO tobaccos deliver higher amounts of nicotine than the 3R4F tobacco. On average, the yield of the different chemical families of compounds appearing in the particulate matter retained in the cigarette filters tends to be around three times higher than those obtained from 3R4F, whereas similar values have been obtained in the particulate matter retained in the traps located after the filters. It can be concluded that RYO tobaccos are not less hazardous than the reference tobacco, which may be contrary to popular belief.

Comments on the Methods of Characterization of Textural Properties of Solids from Gas Adsorption Data

Certain drawbacks of several of the conventional methods of analyzing Type I and II adsorption isotherms frequently used to characterize the structural properties of adsorbent materials have been demonstrated. A simple and flexible procedure, based on an equation combining the Dubinin equation to account for the micropore contribution and the BET equation to account for the non-porous contribution, has been proposed which is capable of simultaneously correlating the adsorption isotherm up to relative pressures of 0.4. Examples are presented showing that the suggested procedure provides a proper interpretation of the data coherent with the origin of the samples and avoids the misinterpretation that could arise from the application of the conventional methods.

TGA-FTIR study of the pyrolysis of sodium citrate and its effect on the pyrolysis of tobacco and tobacco/SBA-15 mixtures under N2 and air atmospheres: TGA-FTIR study of the pyrolysis of sodium citrate

In this work, the effect of sodium citrate mixed with tobacco, in the presence and absence of SBA-15 material, was studied by thermogravimetric analysis coupled to Fourier-transform infrared spectrometry under N2 and air atmospheres. Depending on the atmosphere used, the decomposition of sodium citrate changes considerably at high temperatures, mainly due to the oxidation of the residue. The analysis of the experimental and calculated derivative thermogravimetric data of the sodium citrate/SBA-15 mixtures allows the observation of marked widening of the peaks appearing at lower temperatures, due to the presence of SBA-15, while the expected peak at high temperatures in air completely disappears. The presence of sodium citrate in tobacco and tobacco/SBA-15 mixtures produces changes, especially in air atmosphere, where the main peaks increase their intensity, whereas decreasing that of the oxidation of the residue at around 450 °C and an important peak appears at 630 °C. In N2 atmosphere, all decomposition processes of tobacco proceed at lower temperatures and with higher intensities. The peak due to the citrate at temperatures around 200 °C completely disappears in all samples.