Measuring volatile nicotine from electronic cigarettes

Abstract: This thesis is focused on electronic cigarettes and the formulations (also known as e-juices) associated with these. The reason is that there have been countless studies on the health effects and nicotine delivery of normal cigarettes, but not as much on electronic cigarettes. This work aims to provide some insights into how electronic cigarettes behaves as nicotine delivery system. The overall research question is how different compositions of e-juice affects the release of nicotine vapor from the produced aerosol particles. Depending on if the nicotine is in gas phase or aerosol particle phase effects how the deposition and uptake occurs in the body. This is interesting to be able to compare nicotine delivery of electronic cigarettes to normal cigarettes, as well as understand the effect of e-cigarettes better. This thesis looked at how e-juice with propylene glycol compares to the use of glycerol, but also how addition of water changes the results. Along the way, different parameters were studied to see how, or if, the nicotine evaporation changed as well as size distribution for the aerosol particles formed. A denuder with oxalic acid coating was used to catch the nicotine vapor leaving the aerosol particle as well as oxalic coated filters at the end. The purpose of the filters was to capture all the aerosol particles. For the size measurements, a scanning mobility particle sizer (SMPS) as well as a next generation impactor (NGI) was used to study how the different formulations affected the size distribution. An aerosol mass spectrometer (AMS) was also used to see how the chemical composition of the aerosol particles changed over time. The key result was that glycerol in the e-juice increases the vapor release between 2-4 times compared to propylene glycol. It was observed that for propylene glycol the addition of water did not affect the release significantly, while for glycerol a larger change could be seen. The size of the aerosol particles was similar regardless of formulation. The conclusion drawn from this is that there is a clear difference in nicotine evaporation depending on the e-juice used, where glycerol has a higher evaporation of nicotine compared to propylene glycol. What is unexpected is that it does not seem to be due to difference in size distribution of the aerosol particles but rather due to the chemical composition.