<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The vapor pressure of nicotine has been reported for unprotonated nicotine and for nicotine-water solutions. Yet no published values exist for nicotine in any commercially relevant matrix or for protonated forms (e.g., tobacco, smoke, electronic cigarette solutions, nicotine replacement products, nicotine salts). Therefore a methodology was developed to measure nicotine activity (defined as the vapor pressure from a matrix divided by the vapor pressure of pure nicotine). The headspace concentration of nicotine was measured for pure nicotine and tobacco stored at 23, 30, and 40 °C which allowed for conversion to vapor pressure and nicotine activity and for the estimation of enthalpy of vaporization. Burley, Flue-cured, Oriental, and cigarette blends were tested. Experiments were conducted with pure nicotine initially until the storage and sampling techniques were validated by comparison with previously published values. We found that the nicotine activity from tobacco was less than 1% with Burley > Flue-cured > Oriental. At 23 °C the nicotine vapor pressure averaged by tobacco type was 0.45 mPa for Oriental tobacco, 1.8 mPa for Flue-cured, 13 mPa for Burley while pure nicotine was 2.95 Pa. In general, the nicotine activity increased as the (calculated) unprotonated nicotine concentration increased. The nicotine enthalpy of vaporization from tobacco ranged from 77 kJ/mol to 92 kJ/mol with no obvious trends with regard to tobacco origin, type, stalk position or even the wide range of nicotine activity. The mean value for all tobacco types was 86.7 kJ/mol with a relative standard deviation of 6.5% indicating that this was an intrinsic property of the nicotine form in tobacco rather than the specific tobacco properties. This value was about 30 kJ/mol greater than that of pure nicotine and is similar to the energy needed to remove a proton from monoprotonated nicotine.</p></abstract>

The vapor pressure of nicotine has been reported for unprotonated nicotine and for nicotine-water solutions. Yet no published values exist for nicotine in any commercially relevant matrix or for protonated forms (e.g., tobacco, smoke, electronic cigarette solutions, nicotine replacement products, nicotine salts). Therefore a methodology was developed to measure nicotine activity (defined as the vapor pressure from a matrix divided by the vapor pressure of pure nicotine). The headspace concentration of nicotine was measured for pure nicotine and tobacco stored at 23, 30, and 40 °C which allowed for conversion to vapor pressure and nicotine activity and for the estimation of enthalpy of vaporization. Burley, Flue-cured, Oriental, and cigarette blends were tested. Experiments were conducted with pure nicotine initially until the storage and sampling techniques were validated by comparison with previously published values. We found that the nicotine activity from tobacco was less than 1% with Burley > Flue-cured > Oriental. At 23 °C the nicotine vapor pressure averaged by tobacco type was 0.45 mPa for Oriental tobacco, 1.8 mPa for Flue-cured, 13 mPa for Burley while pure nicotine was 2.95 Pa. In general, the nicotine activity increased as the (calculated) unprotonated nicotine concentration increased. The nicotine enthalpy of vaporization from tobacco ranged from 77 kJ/mol to 92 kJ/mol with no obvious trends with regard to tobacco origin, type, stalk position or even the wide range of nicotine activity. The mean value for all tobacco types was 86.7 kJ/mol with a relative standard deviation of 6.5% indicating that this was an intrinsic property of the nicotine form in tobacco rather than the specific tobacco properties. This value was about 30 kJ/mol greater than that of pure nicotine and is similar to the energy needed to remove a proton from monoprotonated nicotine.

The Activity and Enthalpy of Vaporization of Nicotine from Tobacco at Moderate Temperatures

St.Charles Consultancy, 585 Eden Rock Road, Lewisville, NC 27023, USA

R.J. Reynolds Tobacco Co. 950 Reynolds Boulevard Winston-Salem, NC 27105, USA

Contributions to Tobacco & Nicotine Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The vapor pressure of nicotine has been reported for unprotonated nicotine and for nicotine-water solutions. Yet no published values exist for nicotine in any...

The Activity and Enthalpy of Vaporization of Nicotine from Tobacco at Moderate Temperatures

Published Online: Feb 03, 2016

Page range: 11 - 19

Received: May 05, 2015

Accepted: Jan 11, 2016

DOI: https://doi.org/10.1515/cttr-2016-0003

Keywords
Vapor pressure, enthalpy of vaporization, headspace, nicotine, activity, Burley, Flue-cured, Oriental, 3R4F Kentucky Reference Cigarette

© Beiträge zur Tabakforschung International

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The Activity and Enthalpy of Vaporization of Nicotine from Tobacco at Moderate Temperatures

Published Online: Feb 03, 2016

Page range: 11 - 19

Received: May 05, 2015

Accepted: Jan 11, 2016

DOI: https://doi.org/10.1515/cttr-2016-0003

KeywordsVapor pressure, enthalpy of vaporization, headspace, nicotine, activity, Burley, Flue-cured, Oriental, 3R4F Kentucky Reference Cigarette

© Beiträge zur Tabakforschung International

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Vapor pressure, enthalpy of vaporization, headspace, nicotine, activity, Burley, Flue-cured, Oriental, 3R4F Kentucky Reference Cigarette