title: Analysis of refill liquids for electronic cigarettes.
abstract: OBJECTIVE
  To assess levels of nicotine, nicotine degradation products and some specific impurities in commercial refill liquids for electronic cigarettes.
  
  
  METHODS
  We analyzed 20 models of 10 of the most popular brands of refill liquids, using gas and liquid chromatography.
  
  
  METHODS
  We assessed nicotine content, content of the known nicotine degradation products and impurities, and presence of ethylene glycol and diethylene glycol.
  
  
  RESULTS
  The nicotine content in the bottles corresponded closely to the labels on the bottles. The levels of nicotine degradation products represented 0-4.4% of those for nicotine, but for most samples the level was 1-2%. Cis-N-oxide, trans-N-oxide, myosmine, anatabine and anabasine were the most common additional compounds found. Neither ethylene glycol nor diethylene glycol were detected.
  
  
  CONCLUSIONS
  The nicotine content of electronic cigarette refill bottles is close to what is stated on the label. Impurities are detectable in several brands above the level set for nicotine products in the European Pharmacopoeia, but below the level where they would be likely to cause harm.
authors.affiliation: Institute of Social and Preventive Medicine, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, Geneva, Switzerland. Jean-Francois.Etter@unige.ch
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Etter
authors.forename: Eva
authors.initials: E
authors.lastname: Zäther
authors.forename: Sofie
authors.initials: S
authors.lastname: Svensson
mesh_terms: D019855:Ethylene Glycol / Q000032:analysis; D005026:Ethylene Glycols / Q000032:analysis; D009538:Nicotine / Q000032:analysis*; D061485:Tobacco Use Cessation Devices
chemical_list: D005026:Ethylene Glycols; C013484:diethylene glycol; D009538:Nicotine; D019855:Ethylene Glycol
keywords: Electronic cigarette; electronic nicotine delivery systems; nicotine; quality control; smoking; tobacco