METHODS FOR FORMING AEROSOL-GENERATING SUBSTRATES HAVING A REDUCED AMOUNT OF TOBACCO SPECIFIC NITROSAMINES

Abstract

There is provided a method of forming an aerosol-generating substrate, the method including providing a liquid nicotine source containing at least one tobacco-specific nitrosamine; mixing the liquid nicotine source with a solvent and at least one aerosol former to form an aerosol-generating substrate; and irradiating the aerosol-generating substrate with ultraviolet light to reduce an amount of the at least one tobacco-specific nitrosamine. Also provided is a method of forming an aerosol-generating substrate, the method including providing a tobacco slurry containing at least one tobacco-specific nitrosamine; irradiating the tobacco slurry with ultraviolet light to reduce an amount of the at least one tobacco-specific nitrosamine; and drying the tobacco slurry to form an aerosol-generating substrate.

Claims

1.-14. (canceled)

15. A method for reducing an amount of at least one tobacco-specific nitrosamine in an aerosol-generating substrate, the method comprising: providing a tobacco slurry containing the at least one tobacco-specific nitrosamine; irradiating the tobacco slurry with ultraviolet light; and drying the tobacco slurry to form the aerosol-generating substrate.

16. The method according to claim 15, further comprising casting the tobacco slurry before the drying of the tobacco slurry, wherein the casting the tobacco slurry is performed before or after the irradiating of the tobacco slurry.

17. The method according to claim 15, wherein the ultraviolet light irradiance of the tobacco slurry is at least 4 milliwatts per square centimeter.

18. The method according to claim 15, wherein the tobacco slurry is irradiated with the ultraviolet light for less than 60 minutes.

19. The method according to claim 15, wherein the ultraviolet light has a peak intensity at a wavelength of between 315 nanometers and 400 nanometers.

20. The method according to claim 15, wherein the ultraviolet light has a peak intensity at a wavelength of between 350 nanometers and 380 nanometers.

Description

EXAMPLE 1

[0023] Defined concentrations of N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (380 and 613 nanograms per millilitre, respectively) were added to three different liquid aerosol-generating substrates each consisting of nicotine, glycerin, propylene glycol and water (2:10:68:20, 2:39:39:20 and 2:68:10:20 by weight). Aliquots of these solutions were placed in clear glass vials and irradiated for a specified time (0, 15, 30, 60, 120 or 240 minutes) with ultraviolet radiation (wavelength of 365 nanometres; lamp nominal power of 8 watts; distance to lamp of 3 centimetres). After irradiation the samples were diluted ten-fold with water and their nicotine, NNN and NNK content was analyzed.

[0024] The UV irradiation caused a time-dependent decrease of NNK and NNN in all three nicotine/glycerin/propylene-glycol/water mixtures. Nicotine concentrations were not affected. The nitrosamine decay is approximately exponential with respect to irradiation time. Half-lives for NNN and NNK were in the ranges of 30-50 minutes and 60-70 minutes, respectively. The results are illustrated in FIGS. 1 to 3.

EXAMPLE 2

[0025] A sample sheet of cast tobacco slurry having a thickness of 0.20 to 0.22 millimetres after drying to 195 to 200 grams per square metre was irradiated for 150 minutes, each, on both sides with UV light at a wavelength of 365 nanometres and an intensity of 4.5 milliwatts per square centimetre. After further drying and cutting, the irradiated cast leaf sample and a non-irradiated control were analysed for NNK, NNN, and nicotine content by mass spectroscopy. As compared to the control, the irradiated sample indicated no effect on nicotine content, a reduction of 12 percent in NNK content, and a reduction of 26 percent in NNN content.