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. Accession number 1519 Lorillard Research Center creensh®ro A PROGRESS REPORT ON ACID-INDUCED NICOTINE MIGRATION Dr. R. W. Hurst Submitted by: Dr. R. W. Slaven Report number: Summary or Abstract: Date: 7/15/80 The migration of nicotine as induced by the presence of malic or tartaric acid has been studied. It has been demonstrated that the impregnation of cigarette paper with acid can cause migration of nicotine to the periphery. This in turn elevates delivery of nicotine in mainstream smoke. Preliminary results show no other major migratory species. /le Xc: Ms. M. S. Ireland Dr. Dr. H. F. J. J. Minnemeyer Schultz Library

INTRODUCTION The ability of acid-impregnated media to induce the migra- tion of nicotine is one of the most interesting results observed in these laboratories (1) in connection with work on methods of application and removal of nicotine. Work is now continuing to try and define the scope, utility and mechanism of this phenomenon. Several areas are of particular interest including the distances over which this migration takes place, the type of nicotine ("free" or "bound") involved and any other types of compounds which mi- grate. The distance over which the migration occurs is important for applications in which an attempt is made to move nicotine from the core of the cigarette to the periphery. It is hoped that this would have the effect of enhancing delivery without actually having to add nicotine to the cigarette. Thus, it is necessary to know how far nicotine can be migrated in order to determine if appropriate amounts are available to actually alter delivery. Several experiments involving migration in hand-made cigarettes and through flat pads of reconstituted leaf have been performed to elucidate this point. To determine whether forms of nicotine similar to "bound" nicotine can migrate, rates of equilibration of nicotine salts were studied. Preliminary results using nicotine tartrate are reported here. Finally, a preliminary study of materials which co-migrate with nicotine has been undertaken. This was done to determine if any important flavorants could be detected moving which would result in enhancement or depletion of flavor on specific substrates. EXPERIMENTAL Distance of Transfer Through Reconstituted Leaf In relation to work aimed at achieving migration of nicotine to the outer edges it was of interest to determine the physical distance over which the migration process is effective. This was done by separating nicotine enriched reconstituted leaf (RL) from acid impregnated paper by several layers of normal RL and then analyzing the amount of nicotine which had migrated after heating over an extended time period. The nicotine enriched RL was prepared by dipping 2" x 2.5" rectangles in a 5% aqueous nicotine solution and then air-drying. These samples were then compressed against similar sized pads of RL which contained 1, 2 or 4 layers of RL. The multiple-layer

-2- pads were prepared by thoroughly soaking single sheets of RL and then compressing the appropriate number of sheets into a unified body which was then air dried. Acid impregnated paper was pre- pared by dipping Whatman #2 filter paper in 2 M malic acid sol- ution. Analysis of selected samples of impregnated paper indi- cated it was 29.9 + 5.1% acid by weight (pH = 2.5). The experimental construction consisted of 1 sheet of nico- tine enriched RL pressed against the appropriate multi-layer pad which in turn was pressed against the acid impregnated paper. This assembly was tightly wrapped in alumina foil and put in quart mason jars. Five assemblies were placed in each jar and removed periodically over 3 weeks for analysis. During this time the mason jars were maintained at 1050F. Three different controls were run simultaneous to the actual experiment. These consisted of the two-ply pad construction with the following differences. In control M no malic acid was added to the paper, in N no nicotine was added to the RL and in control I the paper was insulated from the rest of the construction by a piece of waxed laboratory weighing paper. The results of analyses of the individual parts of the various constructions are tabulated in Table 1. In each experiment A refers to the paper, B to the middle pad and C to the single RL sheet. Nicotine Radial Distribution During Migration An earlier memorandum did not report a significant rise in mainstream nicotine delivery even though a substantial amount of nicotine had migrated to the cigarette paper (1). One explana- tion for this phenomenum involved the migration of nicotine only from the perimeter of the cigarette to the paper. To determine the radial distribution of nicotine during the migration process, sixty Golden Light 100 tubes were coated with 100-p1 of 2 M malic acid, allowed to dry, and filled with HH77 tobacco. These cig- arettes were stored in a dessicator containing a 74% glycerin/ water solution which has been reported to maintain moisture levels of 14-15% (2). Samples of 10 cigarettes were taken for nicotine analyses at intervals up to 1 month. A 3.2 mm diameter core was removed from each cigarette by an assembly similar to a cork borer. The tobacco from the periphery, core, and the paper were analyzed for nicotine by Mr. Heath Efird. Results are shown in Table 2. The nicotine levels of the core and perimeter never attained equilibrium. A greater fraction of the nicotine which had migrated to the paper originated from the perimeter than from the core. A mass balance of the nicotine for each portion yields a nicotine 4= level for the original HH77 tobacco of 3.070. This value is in 0 close agreement to the nicotine levels of the core following w migration and indicates there as no significant migration from Zb ~ -1 N

the core. Unfortunately, verification of this number with the analyzed nicotine levels of the stored tobacco before and after the migration time was unreliable. From the 60 malic acid treated cigarettes, two sets of four were selected for mainstream nicotine analysis. Results are shown in Table 3. The controls used here were Golden Light 100 tubes filled with HH77 tobacco, stored with the other cig- arettes for the duration of the experiment. Migration of Nicotine Tartrate To determine the rate at which nicotine salts of stable non-volatile acids migrate.the following experiment was carried out. Pieces of Whatman #2 filter paper were coated with 0.5 ml of 0.02 M aqueous tartaric acid solution. Four such pieces (0.1 mmoles tartaric acid each) were then compressed into a pad. A fifth piece of filter paper was coated with 0.5 ml of 0.1 M nicotine tartrate (total 0.05 mmole) and added to the pad. The assemblies were placed in sealed polyethylene bags and placed in an oven at 80°C for one week. One assembly was then removed and allowed to stand at room temperature for 2 weeks. A second assembly was left in the oven and heated at 105°C for an addit- ional 5 days. The pads were disassembled and each piece of paper analyzed individually. The paper was extracted with 10 ml of water which was subsequently made alkaline with 1 ml of concentrated ammon- ium hydroxide. The aqueous solution was extracted with 3 x 10 ml of FC-113. After addition of an anethole internal standard the freon was brought up to 50 ml and chromatographed isothermally at 170°C on a 6' x 1/16" Carbowax 20M column. Migration of Other Tobacco Constituents In order to determine if any additional tobacco components migrate to acid-impregnated paper, extracts from such paper were subjected to gas chromatographic analysis. The acid-impregnated paper was prepared by dipping 12.5 cm diameter pieces of Whatman #2 filter paper in a 2 M malic acid solution. Selected samples were weighed before dipping and after drying. The malic acid content of the paper was found to be .524 + .09g (29.9 + 5.1%). Twenty-five gram samples of coarsely cut XX-77 burley tobacco were placed into 6 quart mason jars. Into three jars were placed a total of 6 sheets of acid impregnated paper cut into approxi- mately 1" squares. The remaining three jars were charged with filter paper squares (pH = 5.75) which had not been acid treated.

The mason jars were sealed and maintained at 105°F for 5 days with daily agitation. After cooling the jars were opened and the paper separated. The squares were cleaned with a stiff brush to remove tobacco dust. The two types of paper were then extracted with 3 x 100 ml of dry, distilled in glass diethyl ether. After drying with Na2SO4 and filtration the ether solutions were evapo- rated to 0.5 ml under a slow stream of nitrogen. GC analysis of these concentrates was carried out a 25 m x 0.3 m fused silica Carbowax 20M column programmed from 100° to 180°C at 2°/min. The chromatogram (Figure 1) of the extract from the untreated paper shows, as expected, the almost complete absence of nicotine. The only other major difference in the extraction mixtures is the large peak at retention time 6.29 min.in Figure 1 which is absent in the chromatogram (Fig. 2) of the extract from the acid- impregnated paper. DISCUSSION AND CONCLUSIONS The experiments involving nicotine migration and radial migration in cigarettes coated with tartaric acid allow us to draw several important conclusions. It is apparent that nicotine can be made to migrate over a sufficient distance and in sufficient quantities as to make a measurable difference in nicotine delivery. A major problem associated with this type of migration, however, is the observed rate. Since the cigarettes had not attained equilibrium after one month it is apparent that this rate is too slow to be used in a production situation. The rate may be dependent on the composition and concentra- tion of the nicotine salt as shown by the difference in rates between the tartaric acid filter paper experiment and the RL migration. Whether or not the rate can be increased by using higher nicotine tobacco, more acid, or a different acid must be explored. If problems with the rate of migration can be solved the level of nicotine enhancement is in the range that is usable. In terms of the mechanism of migration it is possible that two pathways are operative. The RL pad experiment in which the acid-impregnated paper was insulated from the rest of the con- struction indicates that at least some of the nicotine is moving via the vapor phase. The higher levels of migration noted when the paper is in contact with the RL may be due to a non-vapor phase mechanism or just the greater surface of paper and hence acid available under these conditions.

It should also be noted that nicotine was found on the paper which had not been treated with acid. This is the direct opposite of the result noted in the experiment to determine co-migration. At this point there is no way to completely explain the anomaly. It is possible the difference stems from the presence of added nicotine in the RL experiment and that such nicotine is more easily vol- atilized than that normally found in tobacco. The experiment to analyze for other migrating species gave no indication of any major components besides nicotine. However, since this experiment involved evaporating large amounts of solvent it is possible that volatile components of the extract may have been lost. Further experiments involving use of the Unacon 780 headspace condensor are contemplated to evaluate this possibility. PROPOSALS 1. Determination of effects on nicotine mainstream delivery by a band on the cigarette paper comprised of lactic, citric and malic acids. This band has been found to extinguish the cigarette under conditions of inactive draw (3). 2. Deterrination of the nicotine delivery on double wrap cigarettes where the inner wrap consists of acid or ammonium salt treated paper or reconstituted leaf. 3. Extension of the radial distribution experiment to equili- brium through higher storage temperatures. 4. Quantitation of nicotine migration as a function of nicotine level, acid concentration, temperature, pH and counterion. 5. If transfer of nicotine to the mainstream is increased, an investigation of effects on TPM, CO, CO2 resulting from changes in static burn time and pyrolysis characteristics should be undertaken. 6. Evaluation of taste and impact. 7. Re-examination of extracts via gas chromatography after con- densation using the Unacon 780.

REFERENCES (1) T. M. Larson, "Migration of Nicotine Progress Report I", Lorillard Internal Report, Accession No. 1126, 1978. (2) R. W. Hurst, "Enhancement of Nicotine Delivery by Redistri- bution of Nicotine Within the Cigarette", Memorandum to M. S. Ireland, 1/15/80. (3) R. L. Stedman, L. Lakritz, E. D. Strange, Beit. Z. Tabak- forsch, 5, 13 (1969). (4) V. Norman, A. Ihrig, Private Communication.

TABLE 1 o N I C O T I N E # of plys 5 days 12 days 18 days 20 days A 1A .59 .82 1.00 .74 + .05 1B 1.46 1.79 1.29 1.83 +.03 1C 2.67 2.39 1.20 1.18 +.09 2A .87 .72 .90 1.55 B 1.61 1.38 1.47 1.0 C 1.86 1.84 1.55 1.08 4A .78 .84 - 1.61 B + .1 B .82 .88 - 1.22 + .3 C 2.13 1.63 - 1.25 + .25 2 r1A .54 .57 .75 +.1 A 2MB - 1.10 1.40 1.30 + .1 2MC 2.45 1.58 1.54 + .05 2NA 0.47 .61 .50 .55 + .01 A 2NB 0.75 .62 .57 .61 + .01 2NC 0.73 .60 .60 .47 + .01 21A .58 .62 .60 .70 + 0.04 A 21B .95 1.23 1.02 1.25 + 0.06 21C 2.68 1. 93 1.72 1.32 + 0.15 NOTE: Average thickness of 2-ply pads 1.2 mm, 4-ply pads 2.5 mm.

TABLE 2 Day Paper % Nicotine Perimeter Core 0 - 2.71/3.51* 2.71/3.51* 1 1.11 2.93 3.06 9 1.99 2.82 3.00 13 1.98 2.88 3.08 20 1.99 2.90 3.08 26 1.93 2.90 3.04 * Prior to the experiment, the HH77 tobacco analyzed at 3.51% nicotine,-and at completion, 2.71%. It was stored in a closed glass container at ambient temperature and analyzed at the same time as all the other samples. Insufficient sample remained for repeat determinations

TABLE 3 Control 1 2 pressure drop (mm) 100 100 110 number of puffs/cig. 8 8 10 nicotine/cig. (mg) 1.53 2.13 2.70 % increase from control - 38.9 76.0 Although a significant rise in nicotine is shown in group 1, these results should be considered tentative until a statistical sampling can be acquired. TABLE 4 _ Paper No. GROUP 1 Nicotine (mg) GROUP 2 Nicotine (mg) 4 0 0.77 3 0 0.91 2 0.13 0.97 1 1.44 1.05 N 3.86 1.09