title: Nicotine and Carbonyl Emissions From Popular Electronic Cigarette Products: Correlation to Liquid Composition and Design Characteristics.
abstract: Available in hundreds of device designs and thousands of flavors, electronic cigarette (ECIG) may have differing toxicant emission characteristics. This study assesses nicotine and carbonyl yields in the most popular brands in the U.S. market. These products included disposable, prefilled cartridge, and tank-based ECIGs.
  
  
  
  Twenty-seven ECIG products of 10 brands were procured and their power outputs were measured. The e-liquids were characterized for pH, nicotine concentration, propylene glycol/vegetable glycerin (PG/VG) ratio, and water content. Aerosols were generated using a puffing machine and nicotine and carbonyls were, respectively, quantified using gas chromatograph and high-performance liquid chromatography. A multiregression model was used to interpret the data.
  
  
  
  Nicotine yields varied from 0.27 to 2.91 mg/15 puffs, a range corresponding to the nicotine yield of less than 1 to more than 3 combustible cigarettes. Nicotine yield was highly correlated with ECIG type and brand, liquid nicotine concentration, and PG/VG ratio, and to a lower significance with electrical power, but not with pH and water content. Carbonyls, including the carcinogen formaldehyde, were detected in all ECIG aerosols, with total carbonyl concentrations ranging from 3.72 to 48.85 µg/15 puffs. Unlike nicotine, carbonyl concentrations were mainly correlated with power.
  
  
  
  In 15 puffs, some ECIG devices emit nicotine quantities that exceed those of tobacco cigarettes. Nicotine emissions vary widely across products but carbonyl emissions showed little variations. In spite of that ECIG users are exposed to toxicologically significant levels of carbonyl compounds, especially formaldehyde. Regression analysis showed the importance of design and e-liquid characteristics as determinants of nicotine and carbonyl emissions.
  
  
  
  Periodic surveying of characteristics of ECIG products available in the marketplace is valuable for understanding population-wide changes in ECIG use patterns over time.
authors: Chemistry Department, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon.|Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.
authors: Ahmad
authors: A
authors: El-Hellani
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Mechanical Engineering Department, Faculty of Engineering and Architecture, American University of Beirut, Beirut, Lebanon.
authors: Rola
authors: R
authors: Salman
authors: Chemistry Department, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon.|Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.
authors: Rachel
authors: R
authors: El-Hage
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Mechanical Engineering Department, Faculty of Engineering and Architecture, American University of Beirut, Beirut, Lebanon.
authors: Soha
authors: S
authors: Talih
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Department of Health Promotion and Community Health, American University of Beirut, Beirut, Lebanon.
authors: Nathalie
authors: N
authors: Malek
authors: Chemistry Department, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon.|Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.
authors: Rima
authors: R
authors: Baalbaki
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Mechanical Engineering Department, Faculty of Engineering and Architecture, American University of Beirut, Beirut, Lebanon.
authors: Nareg
authors: N
authors: Karaoghlanian
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Department of Health Promotion and Community Health, American University of Beirut, Beirut, Lebanon.
authors: Rima
authors: R
authors: Nakkash
authors: Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.|Mechanical Engineering Department, Faculty of Engineering and Architecture, American University of Beirut, Beirut, Lebanon.
authors: Alan
authors: A
authors: Shihadeh
authors: Chemistry Department, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon.|Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA.
authors: Najat A
authors: NA
authors: Saliba
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D066300:Electronic Nicotine Delivery Systems / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D005557:Formaldehyde / Q000032:analysis; D006801:Humans; D009538:Nicotine / Q000032:analysis*; D000072137:Vaping / Q000009:adverse effects*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D005557:Formaldehyde; D009538:Nicotine