title: Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations.
abstract: Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography-tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography-mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations.
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Room 2015, PO Box 843079, Richmond, VA 23284, USA mrpeace@vcu.edu.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Peace
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Room 2015, PO Box 843079, Richmond, VA 23284, USA.
authors.forename: Tyson R
authors.initials: TR
authors.lastname: Baird
authors.affiliation: Department of Chemistry, Virginia Commonwealth University, PO Box 842006, Richmond, VA 23284, USA.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Smith
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Room 2015, PO Box 843079, Richmond, VA 23284, USA Department of Pathology, Virginia Commonwealth University, PO Box 980165, Richmond, VA 23298-0165, USA.
authors.forename: Carl E
authors.initials: CE
authors.lastname: Wolf
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298-0613, USA.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Poklis
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Room 2015, PO Box 843079, Richmond, VA 23284, USA Department of Pathology, Virginia Commonwealth University, PO Box 980165, Richmond, VA 23298-0165, USA Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298-0613, USA.
authors.forename: Alphonse
authors.initials: A
authors.lastname: Poklis
mesh_terms: D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D006018:Glycols / Q000032:analysis*; D009538:Nicotine / Q000032:analysis*; D014028:Tobacco Smoke Pollution
chemical_list: D006018:Glycols; D014028:Tobacco Smoke Pollution; D009538:Nicotine