Electronic Cigarette Liquids Research Articles

The Hidden Dangers: E-Cigarettes, Heated Tobacco, and Their Impact on Oxidative Stress and Atherosclerosis—A Systematic Review and Narrative Synthesis of the Evidence

Electronic cigarettes and heated tobacco products have seen significant growth in sales and usage in recent years. Initially promoted as potentially less harmful alternatives to traditional tobacco, recent scientific evidence has raised serious concerns about the risks they pose, particularly in relation to atherosclerosis. While atherosclerosis has long been associated with conventional tobacco smoking, emerging research suggests that electronic cigarettes and heated tobacco may also contribute to the development of this condition and related cardiovascular complications. In a narrative review, we examined the potential effects of heated tobacco products and electronic cigarettes on oxidative stress and atherosclerosis. Several studies have shown that e-cigarettes and heated tobacco increase oxidative stress through the activation of enzymes such as NADPH oxidase. One of the primary effects of these products is their pro-thrombotic and pro-atherosclerotic impact on endothelial cells and platelets, which promotes inflammatory processes within the arteries. Furthermore, the chemicals found in electronic cigarette liquids may exacerbate inflammation and cause endothelial dysfunction. Furthermore, through a systematic review, we analyzed the effects of chronic exposure to electronic and heated tobacco cigarettes on endothelial function, as assessed by brachial flow-mediated dilation (FMD). Although electronic cigarettes and heated tobacco cigarettes are often perceived as safer alternatives to traditional smoking, they could still present risks to cardiovascular health. It is essential to raise public awareness about the potential dangers associated with these products and implement protective measures, particularly for young people.

Evaluating the human abuse potential of concurrent use of electronic cigarettes and low nicotine cigarettes among adults who smoke.

The U.S. Food and Drug Administration has stated its intention to reduce the nicotine content of combustible cigarettes to render them less addictive. This study evaluated the impact of providing adults who smoke with both very low nicotine content cigarettes (VLNCCs) and electronic cigarettes (ECs) of varying nicotine content on measures of human abuse potential. Participants (n = 213) were adult combustible cigarette users. They smoked their usual brand cigarettes (UBCs) during Phase 1 (baseline; week 1) and were provided with and encouraged to exclusively use VLNCCs during Phase 2 (weeks 2-4). During dual-product Phases 3 (weeks 5-7) and 4 (weeks 8-10), participants received both VLNCCs and ECs (assigned to one of two EC devices in higher or lower nicotine concentrations and choice of flavor), with instructions to use them freely in Phases 3 and 4. Assessments included product use, exposure, acceptability, risk perception, and withdrawal-related measures. Results indicated that participants used significantly fewer UBCs during the VLNCC and dual-product phases and smoked fewer VLNCCs during the dual-product phases than the VLNCC-only phase. Neither EC liquid nicotine concentration nor flavor influenced product use. The three study product phases resulted in less product liking and more withdrawal symptoms than the UBC phase. These results suggest that adults who smoke are able to switch much of their tobacco product use from UBCs to VLNCCs and will substitute combustible UBCs and VLNCCs with noncombustible nicotine-containing ECs, but most remain dual users, at least in the short term. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of E-Cigarettes on Combustible Cigarette Smoking Among Adults with Opioid Use Disorder on Buprenorphine: Single Arm ERASER Pilot Trial.

People with opioid use disorder (OUD) on buprenorphine smoke at high rates and have low cessation rates, even with evidence-based medications. Electronic cigarettes (EC) are a promising harm reduction strategy for combusted cigarette (CC) smokers unable to quit. Unfortunately, people with OUD are underrepresented in EC research. A pilot study assessed the feasibility, acceptability, and preliminary effectiveness of EC as a harm reduction tool among CC smokers with OUD on buprenorphine (N=30). Participants were provided with an EC and freebase nicotine liquid (6mg/mL) with a choice of flavor, and a brief training session. Research visits were scheduled in-person at baseline, week 4, and week 8 (follow-up). Daily diary assessments were completed during the 4-week EC period. Most visits (>74%) and 61.4% of daily diary assessments were completed. During the 4-week study period, 90% of participants used the EC at least one day, 66.7% used the EC for at least 16 days, and 43.3% used the EC every day. Significant reductions were observed between baseline and both weeks 4 and 8 in cigarettes smoked per day (CPDbaseline=16.2(8.3), CPDweek4=9.6(9.3), CPDweek8=8.4(8.3)) carbon monoxide (CO) levels (CObaseline=21.5(15.0), COweek4=16.9(9.6), COweek8=15.7(10.0)), and nicotine dependence measured using the Fagerström Test for Nicotine Dependence (FTNDbaseline=5.4(2.5), FTNDweek4=4.2(2.6), FTNDweek8=4.4(2.6))), with all p-values<.05. Implementing an EC protocol in outpatient maintenance treatment programs is feasible and acceptable. Preliminary results suggest that ECs may facilitate reductions in CPD, CO levels, and nicotine dependence. Future research should explore the effect of prolonged EC use on harm reduction and cessation milestones. EC are a potentially promising harm reduction strategy for adult CC smokers with OUD on buprenorphine who are unable to quit using evidence-based medications. However, previous studies have largely overlooked people with OUD on buprenorphine with recent drug use. This study addresses this gap through a pilot trial investigating the feasibility, acceptability, and preliminary effects of EC on CC behavior. The brief and standardized nature of the protocol and its implementation in outpatient settings highlights its potential for widespread implementation in facilities providing care to people with OUD on buprenorphine.

Assessment of human abuse potential of an unflavored, sucralose-sweetened electronic cigarette in combustible cigarette smokers.

Despite the popularity of electronic cigarettes (ECIGs), limited research has examined the role of sweeteners, independent of other flavors, in shaping ECIG human abuse potential (HAP). This study examined the effects of sucralose and nicotine in unflavored ECIG liquid solutions to provide a basic understanding of the effects of sweeteners on ECIG HAP compared to combustible cigarettes. Individuals who smoked cigarettes daily (N = 14) completed five within-subject, Latin-square ordered study sessions that differed by product used: (a) own-brand combustible cigarettes (OB), (b) 0 mg/mL nicotine, unsweetened liquid, (c) 0 mg/mL nicotine, sucralose-sweetened liquid, (d) 15 mg/mL nicotine, unsweetened liquid, and (e) 15 mg/mL nicotine, sucralose-sweetened liquid. Participants completed subjective questionnaires and behavioral tasks following a 10-puff directed use bout during which puff topography was measured, and blood was sampled for later measurement of plasma nicotine concentration. On average, the OB condition had a greater increase in plasma nicotine concentration and produced more pronounced subjective effects compared to the ECIG conditions. The 15 mg/mL nicotine ECIGs delivered significantly more nicotine and produced greater drug effects and reductions in tobacco abstinence symptoms than the 0 mg/mL nicotine ECIGs. Sucralose-containing solutions increased ECIG product appeal, puff duration, and puff volume during the 10-puff directed bout. Findings revealed greater HAP for OB cigarettes relative to all ECIGs tested and suggest that adding sucralose and nicotine elevates ECIG HAP via different mechanisms; sucralose appears to influence HAP through product appeal, while nicotine influences HAP through drug effects and tobacco/nicotine abstinence symptom suppression. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Determination of four tobacco-specific nitrosamines in electronic cigarette liquids and aerosols by UPLC-QTOF-HRMS

To elucidate the concentrations of four tobacco-specific nitrosamines (TSNAs) in commercial e-cigarettes, analyze the correlation between TSNAs and Nicotine, and clarify the main sources of TSNAs in e-cigarettes. Ultra-high performance liquid chromatography with quadrupole time-of-flight high-resolution mass spectrometry (UPLC-QTOF-HRMS) was employed to determine the concentrations of four TSNAs in thirty-two commercially available e-cigarettes. The results demonstrated that the method exhibits excellent linearity and high mass accuracy. The limits of quantification (LOQ) of four TSNAs in e-cigarettes were 0.0010 –0.0165 (e-liquids) and 0.0032–0.0554 (aerosols) ng·g−1. The limits of detection (LOD) of four TSNAs in e-cigarettes were 0.0011–0.0165 (e-liquids) and 0.0033–0.0537 (aerosols) ng·20 puffs−1. The recovery of four TSNAs ranged from 73.06 % to 109.95 %. The e-liquids contained: 0–33.970 (NNN), 0.063–15.654 (NNK), 0–10.033 (NAT), and 0–0.251 (NAB) ng·g−1. The aerosols contained: 0–60.662 (NNN), 0.021–9.435 (NNK), 0.202– 29.866 (NAT), and 0–2.841 (NAB) ng·20 puffs−1. The correlation analysis results have shown that there was no significant correlation between the concentrations of four TSNAs and nicotine in e-cigarettes. The concentrations of four TSNAs in e-liquid containing tobacco extract were significantly higher than that in e-liquid without tobacco extract, suggested that the main source of TSNAs was tobacco extract. This method is fast, simple, highly sensitive, and has low detection limits. The approach taken can provide data support for the actual supervision of e-cigarettes, and evaluation of safety components, contributing to effective quality evaluation systems.

Electronic Cigarette Device and Liquid Characteristics: Comparison of Self-Reports to User-Provided Pictures

Introduction: Self-reports of electronic cigarette (ECIG) device and liquid characteristics are not always accurate or consistent with characteristics as measured by researchers. Two methods for measuring ECIG characteristics were compared: user self-reports and rater-coded pictures. Methods: Exclusive ECIG users (N = 321) reported on device (disposable, refillable, adjustable power, brand) and liquid (nicotine concentration, formulation, flavor) characteristics. To measure device type, they chose the term that best described their device (“cig-alike,” “vape pen,” “mod,” “pod,” “don’t know”) and the picture that best resembled their device (cig-alike, vape pen, box mod, USB-shaped pod, teardrop-shaped pod, none). Respondents uploaded device and liquid pictures, and independent raters coded these same features. Agreement between methods was examined with Cohen’s kappa and intra-class correlations, including with “don’t know” responses included and excluded from analyses. Results: Regardless of how “don’t know” responses were treated, agreement was highest for disposable (95.3–97.7%), refillable (96.3%), adjustable power (83.6–88.7%), and brand (77.9–80.4%), and lower for nicotine concentration (72.7%), nicotine formulation (58.6–79.4%), and flavor (66.2%). For device type, agreement was moderate using both term-based (67.9–78.8%) and picture resemblance-based (71.7%) items. For terms, the greatest discrepancy was for devices classified as “vape pens” by self-reports; of these, 70.6% were classified as “pods” by raters. For picture resemblance, ∼13% of users reported that their device resembled none of the pictures; raters classified these devices as USB-shaped pods (50.0%) and mods (23.8%). Conclusions: Self-reports may be sufficient for measuring some characteristics (brand, disposable, refillable, adjustable power), but not others (nicotine concentration and formulation, and some flavor).

Discrepancies between the stated contents and analytical findings for electronic cigarette liquid products: Identification of the new cannabinoid, Δ9-tetrahydrocannabihexol acetate.

A number of synthetic cannabinoids have been appearing in the recreational drug market for more than a decade. Recent additions are so-called semi-synthetic cannabinoids, and they structurally closely resemble the main psychoactive component of cannabis, Δ9-tetrahydrocannabinol. Knowledge of new (semi-)synthetic cannabinoids is essential to help identify them in authentic forensic case samples. Therefore, the aim of the study was to examine two commercially available electronic cigarette liquid products claiming to contain cannabinoids and characterize the structures of the main compounds. The liquid products were analyzed by gas chromatography-mass spectrometry (GC-MS), GC-quadrupole time-of-flight mass spectrometry (GC-QTOF-MS), and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). In product A, typical cannabinoids (cannabidiol, cannabigerol, and cannabinol) and terpenes (α-caryophyllene and β-caryophyllene) were identified by comparison with reference materials. An unknown peak was isolated by semi-preparative high-performance LC, analyzed by nuclear magnetic resonance (NMR) spectroscopy, and identified to be Δ9-tetrahydrocannabihexol acetate (Δ9-THCH-O). To the authors' knowledge, this is the first report of the identification of Δ9-THCH-O in commercially available products. Another compound estimated as cannabihexol acetate was also detected. In product B, cannabidiol, cannabinol, α-caryophyllene, and β-caryophyllene were identified, while two unknown peaks were estimated as tetrahydrocannabidiol isomers. Despite products A and B being labeled to contain "60% HHCPM" and "80% 10-OH-HHC," respectively, no such compounds were detected. The findings of this study could help detect Δ9-THCH-O in case samples and highlight the need to keep monitoring commercial products to identify new drugs, while warning that the package labels cannot be trusted.

Electronic cigarettes - harmful substances contained in e-cigarette liquids and smoke

Electronic cigarettes and electronic cigarette liquids are increasingly popular in society, especially among young people. However, despite the widespread belief that they are a safe alternative to traditional cigarettes, many scientific studies confirm that electronic cigarettes can be equally, if not more, harmful to health. There are many chemicals in electronic cigarette liquids, such as nicotine, propylene glycol, glycerol, flavors and fragrances. Some of these substances are toxic and can cause a number of negative health effects, such as irritation of the respiratory tract, the onset of lung disease, neurological disorders and increased risk of cardiovascular disease. In addition, electronic cigarettes can be harmful to the environment due to the emission of toxic substances into the air and improper disposal of used batteries. Therefore, an informed approach to the use of electronic cigarettes and an understanding of the potential health risks associated with them is necessary. Further scientific research and education of the public about the harms of electronic cigarettes are key to preventing the negative consequences associated with their use.

Ethyl acetate in e-liquids: Implications for breath testing.

Electronic cigarette liquids (e-liquids) can contain a variety of chemicals to impart flavors, smells and pharmacological effects. Surveillance studies have identified hundreds of chemicals used in e-liquids that have known health and safety implications. Ethyl acetate has been identified as a common constituent of e-liquids. Ethyl acetate is rapidly hydrolyzed to ethanol in vivo. Animal studies have demonstrated that inhaling >2,000 mg/L ethyl acetate can lead to the accumulation of ethanol in the blood at concentrations >1,000 mg/L, or 0.10%. A "Heisenberg" e-liquid was submitted to the Laboratory for Forensic Toxicology Research for analysis after a random workplace drug test resulted in a breath test result of 0.019% for a safety-sensitive position employee. Analysis of this sample resulted in the detection of 1,488 ± 6 mg/L ethyl acetate. The evaluation of purchased "Heisenberg" e-liquids determined that these products contain ethyl acetate. The identification of ethyl acetate in e-liquids demonstrates poor regulatory oversight and enforcement that potentially has consequences for breath ethanol testing and interpretations. The accumulation of ethanol in the breath from the ingestion/inhalation of ethyl acetate from an e-liquid used prior to a breath test may contribute to the detection of ethanol.

Investigation of the in vitro toxic effects induced by real-time aerosol of electronic cigarette solvents using microfluidic chips

The safety of propylene glycol (PG) and vegetable glycerin (VG) as solvents in electronic cigarette liquid has received increasing attention and discussion. However, the conclusions derived from toxicity assessments conducted through animal experiments and traditional in vitro methodologies have consistently been contentious. This study constructed an original real-time aerosol exposure system, centered around a self-designed microfluidic bionic-lung chip, to assess the biological effects following exposure to aerosols from different solvents (PG, PG/VG mixture alone and PG/VG mixture in combination with nicotine) on BEAS-2B cells. The study aimed to investigate the impact of aerosols from different solvents on gene expression profiles, intracellular biomarkers (i.e., reactive oxygen species content, nitric oxide content, and caspase-3/7 activity), and extracellular biomarkers (i.e., IL-6, IL-8, TNF-α, and malondialdehyde) of BEAS-2B cells on-chip. Transcriptome analyses suggest that ribosomal function could serve as a potential target for the impact of aerosols derived from various solvents on the biological responses of BEAS-2B cells on-chip. And the results showed that aerosols of PG/VG mixtures had significantly less effect on intracellular and extracellular biomarkers in BEAS-2B cells than aerosols of PG, whereas increasing nicotine levels might elevate these effects of aerosol from PG/VG mixture.

Extraction and Purification of Nicotine from Tobacco Rhizomes by Supercritical CO2.

Currently, in the ongoing development of the tobacco industry, a large amount of tobacco rhizomes is discarded as waste. These wastes are usually disposed of through incineration or burial. However, these tobacco wastes still have some economic value. High-purity nicotine has a promising market outlook as the primary raw material for electronic cigarette liquid. Nicotine is not only found in tobacco leaves but also in the rhizomes of tobacco plants. This study presents a method for treating tobacco waste and extracting high-purity nicotine from it. After mixing the raw material powder and entrainer in specific ratios, as much of the nicotine in tobacco roots can be extracted as possible using supercritical carbon dioxide extraction. The effects of temperature, the ratio of the entrainer, and the volume fraction of ethanol in the entrainer on the nicotine yield in supercritical fluid extraction (SFE) at 25 MPa for 120 min were discussed. By using 90% ethanol (a raw material mass-to-volume ratio of 1:5) as the entrainer, we obtained the highest nicotine yield of 0.49% at 65 °C. Meanwhile, the purity of the crude extract was 61.71%, and after purification, it increased to 97.57%. In this way, we can not only obtain nicotine with market value but also further reduce the harm to the environment caused by tobacco waste disposal.

Analysis of Coumarin in Tobacco, Smokeless Tobacco Products, and Electronic Cigarette Liquids by Isotope Dilution LC–MS/MS

This article describes a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the analysis of coumarin in various tobacco matrices and electronic cigarette (E-cig) liquids, and highlights the importance of evaluating different MS/MS transitions of an analyte in complex sample matrices to overcome matrix effects. Matrix interfering components were separated from analyte using a C18 ultrahigh-pressure liquid chromatography (UHPLC) column with a larger inner diameter (3.0 mm, or 4.6 mm). Matrix suppressions on analyte responses were corrected by isotope dilution. Four different MS/MS transitions of coumarin were studied in each sample matrix to select a suitable MS/MS transition for analyte quantification based on matrix effects on each MS/MS transition. The method was validated using different tobacco matrices and E-cig liquids.

Reactions to a Hypothetical Ban of Open-System Electronic Cigarettes Among People Who Currently Use Electronic Cigarettes.

Policies limiting electronic cigarette (ECIG) device and liquid characteristics have been considered to prevent dependence potential and youth product appeal. "Open-system" ECIGs allow people to adjust device and liquid characteristics, which may undermine these policies. This study examined anticipated reactions to a policy prohibiting the sale of open-system ECIG devices in the United States using concept mapping. In 2020, adults who reported ECIG use in the past 30 days (n = 70; 45.1% women; mean age = 33.0, SD = 10.6) recruited from a research registry of individuals from across the United States provided statements into a shared list that completed a prompt: "If open-system vaping devices were no longer sold in the US and only closed-system vaping devices were available, what is a specific reaction or response you would have?" at a study website. Participants rated statements (1-7) on how true the statements were for them. Multidimensional scaling and hierarchical cluster analyses were used to identify thematic clusters. Mean ratings of statements were calculated and compared based on the type of ECIG used and current cigarette smoking status. Participants generated 85 unique statements. The analysis identified eight themes that were organized into two broad groups. The first group of five clusters described behavioral responses to the hypothetical policy (Loopholes, Switch to Closed-System ECIGs, Legal Approaches to Use Open-System ECIGs, ECIG Use Cessation, Switch to non-ECIG Products). The second group of three clusters described psychological responses to the hypothetical policy (Closed-System ECIG Cons, Psychological Responses, Policy Outcome Concerns). While a ban on open-system ECIG devices may have positive impacts on public health, policy loopholes, and consumer behaviors may undermine the policy. Efforts to support policy enforcement could increase policy effectiveness. Open-system electronic cigarettes (ECIGs) that allow people who use ECIGs to modify ECIG device and liquid characteristics may limit the effectiveness of policies that establish product standards which attempt to limit nicotine delivery and flavor content in ECIG liquids. This study identified predicted reactions to a hypothetical policy prohibiting the sale of open-system ECIGs in the United States. Results suggest that people who use ECIGs may view a policy prohibiting open-system ECIGs unfavorably, but would be willing to use closed-system ECIGs. However, many ECIG users may attempt to find loopholes in the policy or alternative sources to purchase open-system ECIGs if open-systems were banned. Future research should identify strategies for tobacco regulatory policy enforcement to increase effectiveness.

Genotoxicity and mutagenicity assessment of electronic cigarette liquids.

Electronic cigarettes (e-cigarettes) are often advertised as a safer alternative to traditional smoking. However, recent data suggest they may not be as safe as previously believed. This study aims to evaluate the genotoxicity and mutagenicity of e-cigarette liquids. We randomly selected eight varieties of e-cigarette liquids from the local market in Jeddah, Saudi Arabia. We evaluated their genotoxicity using the Genotoxicity SOS-Chromo Test™ Kit. In this investigation, a rat liver S9 fraction was utilized to emulate liver metabolic function to measure any chemical substance's mutagenic potential. The SOS-Chromo Test was performed by recording the β-galactosidase and alkaline phosphatase activity with and without the metabolic activation enzyme (S-9). All samples, except for the first two dilutions of sample 2, were nongenotoxic in the absence of the S9 activation enzyme, according to the genotoxicity analysis. However, when tested in the presence of the S9 enzyme, samples 2, 4, and 7 exhibited mutagenic activity at varying concentrations. Contrary to common belief, e-cigarettes are not safe. The present investigation confirms the presence of both toxicants and carcinogens in some e-cigarette liquids. This exposure could increase users' risk of various health complications.

Comparison of brain nicotine accumulation from traditional combustible cigarettes and electronic cigarettes with different formulations.

Rapid brain accumulation is critical for the acute reinforcing effects of nicotine. Although nicotine formulation (free-base vs. protonated or salt) in electronic cigarette (E-cig) liquid affects user satisfaction, its impact on brain nicotine accumulation (BNA) from E-cig use has not been evaluated in comparison with traditional combustible cigarettes (C-cigs) using a within-subjects design. BNA was directly assessed with 29 adult dual users (13 females) of E-cigs and C-cigs, using [11C]nicotine and positron emission tomography (PET). Participants underwent two 15-min upper body (from chest to head) scanning sessions during which they inhaled a single puff of [11C]nicotine-labeled vapor from E-cigs with free-base nicotine or C-cig smoke in a randomized order. Seventeen of them also went through another session during which they inhaled from E-cigs with nicotine salt. A full-body scan was also conducted at each session to measure total absorbed dose of [11C]nicotine. Mean maximum nicotine concentration (Cmax) in brain following inhalation of free-base nicotine E-cig vapor was 19% and 15% lower relative to C-cig smoke and nicotine salt E-cig vapor (ps = 0.014 and 0.043, respectively). The Cmax values did not differ significantly between the C-cig and nicotine salt E-cig. Mean values of time to the maximum concentration (Tmax) were not significantly different between the two types of E-cig, but they were 64% and 40% longer than that for C-cig smoking (ps = 0.0005 and 0.004, respectively). Mean Cmax with C-cigs and free-base nicotine E-cigs were greater in females relative to males and correlated with T1/2 of lung nicotine clearance and participants' pack-years. These results suggest that while E-cigs with free-base nicotine formulation can deliver nicotine rapidly to the brain, those with nicotine salt formulation are capable of even more efficient brain nicotine delivery closely resembling combustible cigarettes. Therefore, nicotine formulation or pH in E-liquid should be considered in evaluation of E-cigs in terms of abuse liability and potential in substituting for combustible cigarettes.

On the extension of the use of a standard operating procedure for nicotine, glycerol and propylene glycol analysis in e-liquids using mass spectrometry.

Standard operating procedures (SOP), accessible to several laboratories, are essential for product verification. EU-JATC (European-Joint Action on Tobacco Control) SOP and the WHO TobLabNet (World Health Organization Tobacco Laboratories Network) SOP (SOP11) are available standard methodologies to measure nicotine, glycerol, and propylene glycol, and propose mass spectrometer (MS) as an alternative method to flame ionization detector (FID). This study conducted a comparison between FID and MS concentration results, following the MS method described in SOP11. In May 2020, five test e-liquids in replicates (A-E) were prepared at the Istituto di Ricerche Farmacologiche Mario Negri and sent, with SOP 11, validation document and results datasheet to 32 different laboratories all over the world from WHO TobLabNet and EU-JATC (18 from JATC, ten from WHO TobLabNet and four academic laboratories). Among thirty-two independent laboratories that participated in the study, results were received from 30 laboratories. The e-liquids analyses, using the two approaches, were compared. Of the 30 laboratories surveyed, 21 utilized the FID approach exclusively, 7 opted for MS detection, and 2 employed both methods. The findings demonstrated that the gas chromatography-mass spectrometry (GC-MS) method offers comparable analytical capabilities regarding accuracy and precision for nicotine, glycerol, and propylene glycol to the FID approach. Through Pearson's correlation test with r≃1 showing a positive correlation between GC-FID and GC-MS data, and the Student's t-test, no significant differences between the two approaches were revealed, showing p>0.005 for almost all three analytes in all samples. This study indicates that it is possible to apply the available EU-JATC SOP and the WHO TobLabNet SOP11 even in laboratories that do not have access to an FID, for example, to analyze flavors, trace compounds or carcinogenic, mutagenic, or toxic for reproduction (CMR) in electronic cigarette liquids.

The effect of electronic cigarette liquids on blood biochemistry during chemically induced liver carcinogenesis in rats

The effect of electronic cigarette liquids on blood biochemistry during chemically induced liver carcinogenesis in rats

Electronic Cigarettes on Sperm Quality: Review in Animal and Human Study

Electronic cigarettes that are currently popular are used as nicotine replacement therapy. There are several substances contained in electronic cigarette liquid that have carcinogenic effects. These substances can also increase free radicals which in turn can cause oxidative stress. Nicotine, propylene glycol, and glycerin can cause disturbances in male reproductive function. Infertility can occur due to lifestyle factors, one of which is smoking. Nicotine found in cigarettes can reduce sperm quality, including concentration, mobility, viability, and sperm morphology. The purpose of this study was to determine the effect of electronic cigarettes on sperm quality. The research method uses a literature review system. The twelve studies that are in accordance with the topic of discussion are experimental studies on mice and rats, two studies on human, and one study on both human and rats. Five journals showed a significant decrease in sperm count and testosterone serum level, three other journals showed a significant decrease in sperm morphology and viability, six journals showed a decrease in sperm motility, seven journals showed a significant impairment of testis histological structure, four journals showed a decrease of steroidogenesis enzymes, and one journal showed a significant increase of DNA fragmentation due to the use of electronic cigarettes. Electronic cigarettes had an effect on sperm quality.

HKUST−1 loaded Ag/TiO2 nanoparticles/graphene oxide composites modified sensor for sensitive detection of nicotine in electronic cigarette liquids

Electronic cigarettes (e-cigarette) have become more and more popular among young smokers in recent years. Nicotine, the main addictive component in cigarettes, is widely present in many e-cigarette. Assessing levels of nicotine is critical to the health of consumers and the development of tobacco industry. Herein, a novel electrochemical sensor based on Ag/TiO2 nanoparticles, metal–organic frameworks (MOFs) and graphene oxide (dual−NPs@HKUST−1/GO) nanocomposite was prepared for the rapid detection of nicotine in e-cigarette. The composites were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy, respectively. The results showed that the successfully synthesized composites have an average size of (20 ± 5) μm and excellent characterization properties. Under optimized conditions, the peak current response of nicotine with the differential pulse voltammetry showed a linear relationship in the range of 0.025–300 μM with a detection limit of 0.0145 μM. This newly developed dual−NPs@HKUST−1/GO-based sensor exhibited excellent selectivity, sensitivity and reproducibility for the accurate detection of nicotine. In addition, it also has excellent performance in detecting nicotine in actual e-cigarette refill liquids. The recoveries ranged from 88.6 % to 101.8 % in e-cigarette refill liquids, indicating good detection performance. This method provides a new concept for the detection of nicotine in the tobacco industry and clinical fields.

A new in vitro study demonstrates that electronic cigarettes promote cellular carcinogenic characteristics.

Electronic cigarettes have been used as a new form of cigarettes, especially among young people, but the impact of these effects on mouth cancer is unknown. Therefore, there is a need for studies to evaluate their impact on health and oral mucosa. In this way, this study evaluates the risk of electronic cigarette liquid on in vitro cells of a panel: normal oral epithelium cell lines (NOE and HMK), oral squamous cell carcinoma human cell lines (CAL27 and HSC3), and a mouse oral cancer cell line (AT84). It was demonstrated that electronic cigarettes promote proliferation and anchorage-independent growth and induces morphological changes associated with enhanced motility and invasive phenotypes. Also, it was observed that the enhanced invasive migratory activity associated with the loss of epithelial markers, such as E-cadherin, and the acquisition of mesenchymal markers, strongly suggest that epithelial cells are undergoing to an aggressive phenotype within the framework of epithelial-mesenchymal transition. In conclusion, the liquid can promote carcinogenesis, in addition to promoting an aggressive phenotype in pre-existing lesions.