Serban C. Moldoveanu

Particle Size Distribution of E-Cigarette Aerosols and the Relationship to Cambridge Filter Pad Collection Efficiency

Abstract The relatively volatile nature of the particulate matter fraction of e-cigarette aerosols presents an experimental challenge with regard to particle size distribution measure-ments. This is particularly true for instruments requiring a high degree of aerosol dilution. This was illustrated in a previous study, where average particle diameters in the 10-50 nm range were determined by a high-dilution, electrical mobility method. Total particulate matter (TPM) masses calculated based on those diameters were orders of magnitude smaller than gravimetrically determined TPM. This discrepancy was believed to result from almost complete particle evaporation at the dilution levels of the electrical mobility analysis. The same study described a spectral transmission measurement of e-cigarette particle size in an undiluted state, and reported particles from 210-380 nm count median diameter. Observed particle number concentrations were in the 109 particles/cm3 range. Additional particle size measurements described here also found e-cigarette particle size to be in the 260-320 nm count median diameter range. Cambridge filter pads have been used for decades to determine TPM yields of tobacco burning cigarettes, and collection of e-cigarette TPM by fibrous filters is predicted to be a highly efficient process over a wide range of filtration flow rates. The results presented in this work provide support for this hypothesis. Described here is a study in which e-cigarette aerosols were collected on Cambridge filters with adsorbent traps placed downstream in an effort to capture any material passing through the filter. Amounts of glycerin, propylene glycol, nicotine, and water were quantified on the filter and downstream trap. Glycerin, propylene glycol, and nicotine were effciently captured (> 98%) by the upstream Cambridge filter, and a correlation was observed between filtration efficiency and the partial vapor pressure of each component. The present analysis was largely inconclusive with regard to filter efficiency and particle-vapor partitioning of water. [Beitr. Tabakforsch. Int. 26 (2014) 183-190]

Nicotine Analysis in Several Non-Tobacco Plant Materials

Summary Present study describes the determination of nicotine in various plant samples with a low content of this compound. Nicotine is found naturally in plants from the Solanaceae family. The plants from Nicotiana genus contain large levels of nicotine. However, only low levels are present in plants from Solanum genus including potato, tomato, eggplant, and from Capsicum genus, which are used as food. Because the levels of nicotine in these materials are in the range of parts per billion, the measurements are difficult and the results are very different from study to study. The present study evaluated the level of nicotine in a number of plants (fruits, roots, leaves, tubers) from Solanaceae family (not including Nicotiana genus) and from several other vegetables commonly used as food. The analysis consisted of the treatment of plant material with an aqueous solution 5% NaOH at 70°C for 30 min, followed by extraction with TBME containing d3-nicotine as an internal standard. The TBME organic layer was analyzed on a 7890B/7000C GC-MS/MS system with a 30 m × 0.25 mm, 0.25 μm film CAM column. The MS/MS system worked in MRM positive ionization mode monitoring the transition 162 - 84 for nicotine and 165 - 87 for d3-nicotine. Particular attention was given to the preservation of the intact levels of nicotine in the plant material. The plant material was analyzed as is, without drying and with minimal exposure to contaminations. Separately, the moisture of the plant material was measured in order to report the nicotine level on a dry-basis. Levels of nicotine around 180 ng/g dry material were obtained for tomatoes and eggplant (fruit) and lower levels were obtained for green pepper and potato. Similar levels to that in the tomato fruit were detected in tomato leaves. Materials from other plant families also showed traces of nicotine. [Beitr. Tabakforsch. Int. 27 (2016) 54-59]

Evaluation of Several Minor Alkaloid Levels in Tobacco with Separation of R- and S-Nornicotine

Abstract The chiral separation of minor alkaloids from tobacco is of interest because R and S isomers of these compounds have differences in their physiological activity. This difference is also reflected in the physiological properties of tobaccospecificN’-nitrosamines (TSNAs), in particular that of N’-nitrosonornicotine. This compound results mainly from nornicotinenitrosation. The previously reported analytical techniques for the enantiomer separation of minor alkaloids have various shortcomings, such as the need for bidimensional chromatography or poor enantiomer separation. A new method for the analysis of nornicotine, anabasine and anatabine has been developed, based on an original derivatization and a simple gas chromatography/ mass spectrometry (GC/MS) analysis. The method allows separate quantitation of S-nornicotine and R-nornicotine, and the analysis of anabasine and anatabine (without isomer separation). It was found that the proportion of S-nornicotine in the total nornicotine present in tobacco varies, depending on the tobacco type, between 52.6% for a flue-cured tobacco to 91.4% for a Burley. Green tobaccos (freeze dried) showed lower levels of minor alkaloids and S-nornicotine accounted for between 31.6% to 43.8% of the total nornicotine (in the analyzed samples).

Analysis of Certain Nitrogenous Compounds in Tobacco. Part 1: Adenosine, 2,5- and 2,6-Deoxyfructosazines, Mannosamine and Glucosamine

Abstract Nitrogenous compounds such as amino acids and proteins are frequently analyzed in tobacco since they are considered precursors of toxicants in cigarette smoke. However, much less attention is given to other nitrogenous compounds such as amino sugars and deoxyfructosazines, although their concentration in tobacco can be equal to or even higher than that of most free amino acids. These nitrogenous compounds may contribute to the formation of toxicants in smoke, or may contribute to the sensory properties of cigarette smoke, reasons for which their analysis is important. This study describes a procedure for the analysis of adenosine, 2,5- and 2,6-deoxyfructosazines (DFs), mannosamine and glucosamine in tobacco. The analysis uses a liquid chromatographytandem mass spectrometry (LC/MS/MS) technique. Sample preparation for analysis consists of the extraction of the tobacco with a solution of 90% water and 10% methanol, followed by filtration. The separation of the analytes was done on a hydrophilic interaction liquid chromatography HILIC column using an isocratic procedure with a solvent consisting of 78% CH3CN, 22% H2O, that also contained 0.1 % HCOOH and 0.143 g/L CH3COONH4. The measurements were done using electrospray positive ionization mass spectrometric detection. The analytical procedure was validated and was proven very reliable. A number of tobaccos were analyzed, including several fluecured and Burley USA tobaccos, off-shore tobaccos, two Oriental tobaccos, two green tobaccos, as well as tobaccos from commercial and Kentucky reference cigarettes. The ranges for the analytes per g tobacco were found between 0.4 and 20.3 µg/g for adenosine, between 0.0 and 608.5 µg/g for 2,5-DF, between 0.0 and 424.5 µg/g for 2,6-DF, between 12.5 and 415.5 µg/g for mannosamine and between 25.9 and 1885.7 µg/g for glucosamine. The study also indicated that the levels of DFs and that of the amino sugars in tobacco show a very good correlation. This correlation can be explained by the same source of the two classes of compounds, namely the reaction of (reducing) sugars and ammonia.

An LC-MS Method for the Analysis of Some Organic Acids in Tobacco Leaf, Snus, and Wet Snuff

Summary The present study describes the analysis of several organic acids in tobacco and smokeless tobacco products using a liquid chromatography (LC) method with mass spectrometric (MS) detection (LC-MS). Prior to the application of the LC-MS method, a qualitative analysis for the identification of the organic acids in tobacco and oral tobacco products was performed. The qualitative method used direct silylation of the plant material followed by GC-MS separation and detection. For the acids’ quantitation, a novel LC-MS method has been developed and validated. The acids of interest for quantitation were the following: acetic, citric, fumaric, glyceric, lactic, maleic, malic, oxalic, pyroglutamic, pyruvic, quinic, and trihydroxybutanoic. The LC separation was performed on a Synergy 4u Hydro-RP column 250 × 4.6 mm, with an aqueous mobile phase containing 5% methanol and 0.15% formic acid. The LCMS method has the advantage versus LC methods with other detection types (refractive index, UV absorption at low UV range, or conductivity) of being capable of positive identification of the analytes based on their specific ions, and of having significantly better sensitivity. Unfortunately, the LC-MS method was not generating good results for oxalic acid and acetic acid also expected to be present in some samples of tobacco or tobacco products. The study describes the advantages and disadvantages of the LC-MS method for the analysis of organic acids in tobacco and smokeless tobacco products.