RESEARCH PAPER
Universal electronic-cigarette test: physiochemical characterization of reference e-liquid
 
More details
Hide details
1
Clinical Research, Volpe Research Center, ADA Foundation, 100 Bureau Drive Stop 8546 NIST, Gaithersburg, MD 20899, USA
2
School of Engineering, University of Maryland College Park, College Park, MD, USA
3
Present address: Food and Drug Administration, Silver Spring, MD, USA
4
Molecular Characterization and Analysis Complex, University of Maryland Baltimore County, Baltimore, MD, USA
5
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
6
Department of Chemistry and Biochemistry, University of Maryland College Park, College Park, MD, USA
Publish date: 2017-02-16
 
Tob. Induc. Dis. 2017;15(February):14
KEYWORDS:
ABSTRACT:
Background:
Despite the rising health and safety concerns of e-cigarettes, a universal e-cigarette testing method is still in its early developmental stage. The aim of this study was to develop an e-liquid Reference Material that can be used to improve accuracy and reproducibility of research results, and advance health risk assessment of e-cigarette products.

Methods:
E-liquid Reference Material was developed by purity assessment, gravimetric measurement, homogeneity testing, and stability testing with material and instrument traceability (adopted from ISO 35:2006E).

Results:
Homogeneity tests showed e-liquid Reference Material requires ≥ 1 h rotation at a speed of 5 rpm to reach complete homogeneity. Stability tests showed homogeneity is intact for at least 2 weeks without secondary separation, and e-liquids are stable in 21 °C–50 °C thermocycling conditions up to 72 h. A change in the e-liquid color was first observed at day seven, and progressed to 2- and 16 - fold increase in absorbance by one and 6 months respectively. We found that e-liquids do not have inherent material instabilities such as immiscibility or secondary separation. However, discrepancies in concentration and composition arose mainly due to viscosity of propylene glycol and glycerin. Aerosol generated from the e-liquid Reference Material had 16 chemical-byproducts and was composed of ~634,000 particles of which 38% were Fine Particulate Matters (<0.5 μm in diameter).

Conclusions:
The efforts described here to create a standardized e-liquid Reference Material aim to provide unbiased and robust testing parameters that may be useful for researchers, the industry and government agencies. Additionally, the reference e-liquid could open a channel of conversation among different laboratories by providing the means of independent verification and validation while establishing a system of transparency and reproducibility in materials and methods.

CORRESPONDING AUTHOR:
Jeffrey J. Kim   
Clinical Research, Volpe Research Center, ADA Foundation, 100 Bureau Drive Stop 8546 NIST, Gaithersburg, MD 20899, USA
 
REFERENCES (36):
1. Pisinger C, Dossing M. A systematic review of health effects of electronic cigarettes. Prev Med. 2014;69:248–60.
2. Johnston LD, O’Mally PM, Miech RA, et al. Monitoring the future. National survey results on drug use: 1975–2014 Overview key findings on adolescent drug use. 2014. http://www.monitoringthefuture.... Accessed 29 Mar 2016.
3. World Health Organization. WHO Framework convention on tobacco control electronic nicotine delivery systems. Moscow: Russian Federation; 2014.
4. King BA, Patel R, Nguyen KH, et al. Trends in awareness and use of electronic cigarettes among US adults, 2010-2013. Nicotine Tob Res. 2015;17(2):219–27.
5. Chatham-Stephens K, Law R, Taylor E, et al. Notes from the field: calls to poison centers for exposures to electronic cigarettes - United States, September 2010-February 2014. MMWR. 2014;63(13):292–3.
6. Corey C, Wang B, Johnson SE, et al. Notes from the field: electronic cigarette use among middle and high school students - United States, 2011–2012. MMWR. 2013;62(35):729–30.
7. Tomar SL, Fox CH, Connolly GN. Electronic cigarettes the tobacco industry’s latest threat to oral health? JADA. 2015;146(9):651–3.
8. Harvard T.H. Chan School of Public Health and STAT. Americans’ perspectives on e-cigarettes. 2015. https://cdn1.sph.harvard.edu/w.... Accessed 29 Mar 2016.
9. American Lung Association. Statement on e-cigarettes. 2015. http://www.lung.org/our-initia.... Accessed 29 Mar 2016.
10. Schoenborn CA, Gindi RM. Electronic cigarette use among adults: United States. 2014. October 2015. http://www.cdc.gov/nchs/produc.... Accessed 27 Sept 2016.
11. Filippidis FT, Laverty AA, Gerovasili V, et al. Two-year trends and predictors of e-cigarette use in 27 European Union member states. Tob Control. 2016;23 Suppl 0:iii1–7.
12. Action on Smoking and Health. Use of electronic cigarettes (vapourisers) among adults in Great Britain. 2016. http://www.ash.org.uk/files/do.... Accessed 27 Sept 2016.
13. Lindblom EN. Effectively regulating e-cigarettes and their advertising and the first amendment. Food Drug Law J. 2015;70(1):55–92.
14. Pearson JL, Richardson A, Niaura RS, et al. E-cigarette awareness, use, and harm perceptions in US adults. Am J Public Health. 2012;102(9):1758–1766.
15. Zhu SH, Sun JY, Bonnevie E, et al. Four hundred and sixty brands of e-cigarettes and counting: implications for product regulation. Tob Control. 2014;23 Suppl 3:iii3–9.
16. Huang, Y. E-Cigarettes: China's next growth industry. May 2014. http://www.forbes.com/sites/ya.... Accessed 27 Sept 2016.
17. Brown CJ, Cheng JM. Electronic cigarettes: product characterisation and design considerations. Tob Control. 2014;23 Suppl 2:ii4–10.
18. Callahan-Lyon P. Electronic cigarettes: human health effects. Tob Control. 2014;23 Suppl 2:ii36–40.
19. Orr MS. Electronic cigarettes in the USA: a summary of available toxicology data and suggestions for the future. Tob Control. 2014;23 Suppl 2:ii18–22.
20. Goniewicz ML, Kuma T, Gawron M, et al. Nicotine levels in electronic cigarettes. Nicotine Tob Res. 2013;15(1):158–66.
21. Hutzler C, Paschke M, Kruschinski S, et al. Chemical hazards present in liquids and vapors of electronic cigarettes. Arch Toxicol. 2014;88(7):1295–308.
22. Trehy ML, Ye W, Hadwiger ME, et al. Analysis of electronic cigarette cartridges, refill solutions, and smoke for nicotine and nicotine related impurities. J Liq Chromatogr Relat Technol. 2011;34(14):1442–58.
23. Goniewicz ML, Knysak J, Gawron M, et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob Control. 2014;23(2):133–9.
24. Cobb NK, Byron MJ, Abrams DB, et al. Novel nicotine delivery systems and public health: the rise of the “e-cigarette”. Am J Public Health. 2010;100(12):2340–2.
25. Cameron JM, Howell DN, White JR, et al. Variable and potentially fatal amounts of nicotine in e-cigarette nicotine solutions. Tob Control. 2014;23(1):77–8.
26. Cheah NP, Chong NW, Tan J, et al. Electronic nicotine delivery systems: regulatory and safety challenges: Singapore perspective. Tob Control. 2014;23(2):119–25.
27. Etter JF, Zather E, Svensson S. Analysis of refill liquids for electronic cigarettes. Addiction. 2013;108(9):1671–9.
28. Hadwiger ME, Trehy ML, Ye W, Moore T, Allgire J, Westenberger B. Identification of amino-tadalafil and rimonabant in electronic cigarette products using high pressure liquid chromatography with diode array and tandem mass spectrometric detection. J Chromatogr A. 2010;1217(48):7547–55.
29. Department of Health. Therapeutic Goods Administration. Australian Government. Liquid nicotine and personal importation for use in electronic cigarettes. 2014. https://www.tga.gov.au/behind-.... Accessed 27 Sept 2016.
30. European Comission. The Tobacco Products Directive (2014/40/EU). 2014 http://ec.europa.eu/health/tob.... Accessed 27 Sept 2016.
31. U.S. Food and Drug Administration. New regulations for e-cigarettes, cigars, and all other tobacco products. Family smoking prevention and tobacco control act. 2016. http://www.fda.gov/TobaccoProd.... Accessed 27 Sept 2016.
32. Cheng T. Chemical evaluation of electronic cigarettes. Tob Control. 2014;23 Suppl 2:ii11–17.
33. World Health Organization. Water quality monitoring: a practical guide to the design and implementation of freshwater quality studies and monitoring programmes. 1996. http://www.who.int/water_sanit.... Accessed 29 Mar 2016.
34. Jablonski JE, Schlesser JE, Mariappagoudar P. HPLC-UV method for nicotine, strychnine, and aconitine in dairy products. J Agric Food Chem. 2006;54(20):7460–5.
35. Behar RZ, Hua M, Talbot P. Puffing topography and nicotine intake of electronic cigarette users. PLoS One. 2015;10(2):e0117222.
36. Skoog DA, West DM, Holler FJ. Fundamentals of analytical chemistry. 7th ed. Fort Worth: Saunders College Pub.; 1996.
eISSN:1617-9625