The Use of HPLC-PDA in Determining Nicotine and Nicotine-Related Alkaloids from E-Liquids: A Comparison of Five E-Liquid Brands Purchased Locally

Abstract

E-liquid manufacturers are under scrutiny concerning the purity and concentration accuracy of nicotine and the minor nicotine-related alkaloids (NRAs) packaged in their products. In this communication we report concentrations of nicotine and five NRAs (nornicotine, cotinine, anabasine, anatabine, myosmine) from locally purchased E-liquids. Methods: Five brands of E-liquids (three bottles each) were purchased locally. Additionally, three bottles of reference E-liquid were prepared. Concentrations of nicotine and NRAs from each bottle were measured by HPLC. Concentrations of these alkaloids were also determined from electronic cigarette-generated aerosol and traditional cigarette smoke. Results: Nicotine concentrations in E-liquid brands 1, 2, 3, 4, 5 and in the reference E-liquid were 17.8 ± 4.1, 23.2 ± 0.7, 24.0 ± 0.9, 24.9 ± 0.2, 19.7 ± 0.3 and 20.4 ± 0.1 mg/mL, respectively. Concentrations normalized to 100% of product label were 74%, 97%, 100%, 104%, 109% and 102%, respectively. E-liquid brand 1 showed significance (p < 0.001) between bottles, while the reference showed the least variability. Similar results were obtained for the NRAs. Results also indicated the NRAs in aerosol of the reference E-liquid are lower than in cigarette smoke. Conclusions: The amounts of NRAs present in E-liquids and E-liquid aerosol are less compared to cigarettes, however, inconsistencies and variation in nicotine concentrations supports the need for regulatory oversight.

A Comparison of Flavorless Electronic Cigarette-Generated Aerosol and Conventional Cigarette Smoke on the Planktonic Growth of Common Oral Commensal Streptococci

“…No flavorings were added. The nicotine concentration per cigarette equivalent is higher than the typical concentration of nicotine in a tobacco cigarette but comparable to the high-end nicotine concentration found in a number of commercially available E-liquids [50]. E-liquid was aerosolized using a Tripl3 (Kennesaw, GA, USA) eGo style lithium ion battery (650 mAh, 3.7 V unregulated).…”

“…Standard solutions of 99% (S)-(-)-nicotine, were prepared in BHI broth at concentrations of 0.4, 0.2, and 0.1 mg/mL. Standards and samples of BHI exposed to 25, 50, or 75 puffs of flavorless ECIG aerosol with nicotine or conventional cigarette smoke were analyzed by HPLC coupled with photodiode array detection, as previously described [49,50]. A Shimadzu HPLC system (Columbia, Standard solutions of 99% (S)-(-)-nicotine, were prepared in BHI broth at concentrations of 0.4, 0.2, and 0.1 mg/mL.…”

“…A Shimadzu HPLC system (Columbia, Standard solutions of 99% (S)-(-)-nicotine, were prepared in BHI broth at concentrations of 0.4, 0.2, and 0.1 mg/mL. Standards and samples of BHI exposed to 25, 50, or 75 puffs of flavorless ECIG aerosol with nicotine or conventional cigarette smoke were analyzed by HPLC coupled with photodiode array detection, as previously described [49,50]. A Shimadzu HPLC system (Columbia, MD, USA) was used to quantitate nicotine and included the following: a photodiode array detector (SPD-M20A), dual pumps (LC-20AT), a column oven (CTO-20A), an in-line membrane degasser (DGU-20A3R), and a Rheodyne 7725I manual injector with a 20 µL loop (40 µL injection volume).…”

Simple HPLC method for rapid quantification of nicotine content in e-cigarettes liquids

“…Several studies have revealed that e-liquids containing nicotine used in ENDs are greatly variable than what are stated on labels [6][7][8][9][10][11][12][13][14][15]. Hence, Jordan Food and Drug Administration (JFDA) has recently issued specific legislations for tobacco and nicotine delivery systems including ENDs licensing and regulation in July 2019, which necessitate the utilization of reliable analytical methods to control these products and their contents for quality and safety.…”

“…Since LC is a workhorse technique used for efficient and tedious analytical procedures [19][20][21]. It has been employed successfully for nicotine quantification in e-liquids such as liquid chromatography-mass spectrometry (LC-MS) [6,7], in addition to HPLC with photodiode array detection (HPLC-PDA) [13,14].…”