%0 Journal Article %J Chemosensors %D 2024 %T Spectroscopy and Chemometrics for Conformity Analysis of e-Liquids: Illegal Additive Detection and Nicotine Characterization %A Zeb Akhtar %A Sophia Barhdadi %A Kris de Braeckeleer %A Cedric Delporte %A Erwin Adams %A Eric Deconinck %K e-liquids; spectroscopic techniques; chemometric techniques; data analysis %X

Vaping electronic cigarettes (e-cigarettes) has become a popular alternative to smoking tobacco. When an e-cigarette is activated, a liquid is vaporized by heating, producing an aerosol that users inhale. While e-cigarettes are marketed as less harmful than traditional cigarettes, there are ongoing concerns about their long-term health effects, including potential lung damage. Therefore, it is essential to closely monitor and study the composition of e-liquids. E-liquids typically consist of propylene glycol, glycerin, flavorings and nicotine, though there have been reports of non-compliant nicotine concentrations and the presence of illegal additives. This study explored spectroscopic techniques to examine the conformity of nicotine labeling and detect the presence of the not-allowed additives: the caffeine, taurine, vitamin E and cannabidiol (CBD) in e-liquids. A total of 236 e-liquid samples were carefully selected for analysis. Chemometric analysis was applied to the collected data, which included mid-infrared (MIR) and near-infrared (NIR) spectra. Supervised modeling approaches such as partial least squares-discriminant analysis (PLS-DA) and soft independent modeling of class analogy (SIMCA) were employed to classify the samples, based on the presence of nicotine and the targeted additives. This study demonstrates the efficacy of MIR and NIR spectroscopic techniques in conjunction with chemometric methods (SIMCA and PLS-DA) for detecting specific molecules in e-liquids. MIR with autoscaling data preprocessing and PLS-DA achieved 100% classification rates for CBD and vitamin E, while NIR with the same approach achieved 100% for CBD and taurine. Overall, MIR combined with PLS-DA yielded the best classification across all targeted molecules, suggesting its preference as a singular technique

%B Chemosensors %V 12 %G eng %N 1 %& 9 %R https://doi.org/10.3390/chemosensors12010009 %0 Journal Article %J Journal of Pharmaceutical and Biomedical Analysis %D 2023 %T The analysis of cannabinoids in e-cigarette liquids using LC-HRAM-MS and LC-UV %A Sophia Barhdadi %A Patricia Courselle %A Eric Deconinck %A Celine Vanhee %K Cannabinoids %K CBD-liquids %K e-cigarettes %K LC-HRAM-MS %X

The use of cannabidiol or CBD products has skyrocketed in the last five years due to the alleged therapeutic benefits, a low potential for abuse and lack of the typical psychoactive effects associated with the use of cannabis products containing high levels of ∆9-tetrahydrocannabinol (∆9-THC). In Belgium, CBD-containing e-liquids with a total THC content lower than 0.2% (w/w) are currently legal. In order to verify the compliance of the different CBD-containing e-cigarette liquids that are available to the Belgian population, a method was developed for screening of 17 cannabinoids and to quantify the major cannabinoids such as CBD, CBDA, ∆9-THC and ∆9-THCA. The latter was fully validated using the 'total error' approach, applying accuracy profiles and conforming to ISO17025. None of the analysed samples exceeded the legal limit for the total amount of ∆9-THC present. However, of the 20 CBD-liquids investigated in this study, only 30% of the samples contained an amount of CBD that was within 10% deviation of the label claim. Moreover, the CBD e-liquids labelled "full/broad spectrum" consisted of several minor alkaloids in comparison to the "classic" CBD e-liquids where the acidic forms of the cannabinoids were not present. Currently, no legislation is available for the regulation of CBD e-liquids, however these results indicate that quality controls are pertinent especially concerning the discrepancy in CBD label accuracy.

%B Journal of Pharmaceutical and Biomedical Analysis %V 230 %8 April-2023 %G eng %R 10.1016/j.jpba.2023.115394 %0 Journal Article %J J Pharm Biomed Anal %D 2023 %T The analysis of cannabinoids in e-cigarette liquids using LC-HRAM-MS and LC-UV. %A Sophia Barhdadi %A Patricia Courselle %A Eric Deconinck %A Celine Vanhee %K Cannabidiol %K Cannabinoids %K cannabis %K Chromatography, Liquid %K Dronabinol %K Electronic Nicotine Delivery Systems %K Mass Spectrometry %X

The use of cannabidiol or CBD products has skyrocketed in the last five years due to the alleged therapeutic benefits, a low potential for abuse and lack of the typical psychoactive effects associated with the use of cannabis products containing high levels of ∆9-tetrahydrocannabinol (∆9-THC). In Belgium, CBD-containing e-liquids with a total THC content lower than 0.2% (w/w) are currently legal. In order to verify the compliance of the different CBD-containing e-cigarette liquids that are available to the Belgian population, a method was developed for screening of 17 cannabinoids and to quantify the major cannabinoids such as CBD, CBDA, ∆9-THC and ∆9-THCA. The latter was fully validated using the 'total error' approach, applying accuracy profiles and conforming to ISO17025. None of the analysed samples exceeded the legal limit for the total amount of ∆9-THC present. However, of the 20 CBD-liquids investigated in this study, only 30% of the samples contained an amount of CBD that was within 10% deviation of the label claim. Moreover, the CBD e-liquids labelled "full/broad spectrum" consisted of several minor alkaloids in comparison to the "classic" CBD e-liquids where the acidic forms of the cannabinoids were not present. Currently, no legislation is available for the regulation of CBD e-liquids, however these results indicate that quality controls are pertinent especially concerning the discrepancy in CBD label accuracy.

%B J Pharm Biomed Anal %V 230 %8 2023 Jun 15 %G eng %R 10.1016/j.jpba.2023.115394 %0 Journal Article %J Separations %D 2023 %T The Development and Validation of a Targeted LC-HRAM-MS/MS Methodology to Separate and Quantify p-Synephrine and m-Synephrine in Dietary Supplements and Herbal Preparations %A Celine Vanhee %A Sophia Barhdadi %A Angélique Kamugisha %A Tanika Van Mulders %A Kevin Vanbrusselen %A Marie Willocx %A Eric Deconinck %B Separations %V 10 %8 08/08/2023 %G eng %N 8 %R 10.3390/separations10080444 %0 Generic %D 2023 %T Spectroscopic approaches for conformity analysis of e-liquids %A Zeb Akhtar %A Sophia Barhdadi %A Erwin Adams %A Eric Deconinck %K e-liquids %K IR spectroscopy %X

E-liquids are liquids used in e-cigarettes. They are responsible for creating the vapor that is inhaled by the user. E-cigarettes were created with the intention of assisting smokers in quitting because they are believed to be less dangerous than conventional combustible cigarettes. With a range of flavors and nicotine levels to choose from, as well as the presentation as “the healthier option” and cost-effectiveness, it's no wonder that e-liquids have become increasingly popular in the last 20 years, particularly with younger people. Though, vaping is not without health concerns. The long-term effects  are still not fully understood, and there have been reports of health problems associated with e-cigarette use, including lung damage. Therefore, it is necessary to monitor the compositions of the products on the market and conduct surveillance studies. In Belgium this is performed under the coordination of the Federal Public Service of public health.

E-liquids typically contain four main ingredients: propylene glycol, glycerin, flavorings and nicotine. The latter is of course not present in zero liquids. The primary issue is the content of nicotine. Previous reports showed that nicotine concentrations are not compliant to the label claim, with mean deviations between 5% and 20%. Also zero liquids containing nicotine were encountered. Another issue is the presence of  additives, illegal according to the European Directive. Some of the most important are caffeine, taurine and vitamin E. Cannabidiol (CBD), which is in the gray zone of the legislation, was also taken into account of this study, due to its popularity.

In this study spectroscopic approaches were explored to check the label conformity for nicotine and the presence of caffeine, taurine, vitamin E and CBD in e-liquids. Therefore a set of 236 e-liquids was selected. Since samples with caffeine, taurine, CBD and vitamin E as additives were hard to find, some of the samples were split in two and one of both aliquots was spiked with the targeted additives in realistic concentrations. After sample set preparation, mid-infrared, near-infrared and Raman spectra were recorded for all samples. After obtaining the data matrices, chemometric analysis was performed. For each type of data, the sample matrix was split into a training and  test set. Spectroscopic data were preprocessed before modelling. Next to baseline correction, classical preprocessing techniques like standard normal variate (SNV), derivatives and scaling were explored. In a first step, supervised modelling, using partial least squares-discriminant analysis (PLS-DA) and soft independent modelling by class analogy (SIMCA), was used to classify samples according to the presence of nicotine and/or the targeted additives. The results allowed to classify samples according to nicotine and present additives. So, their presence in new suspected samples could be detected. In a second step, PLS regression was applied to estimate the nicotine concentration and check the label conformity.

%B 21st Forum of Pharmaceutical Sciences %I BGFW %C Blanckenberghe, Belgium %8 27/04/2023 %G eng %N BGFW %0 Generic %D 2022 %T The analysis of cannabinoids in e-cigarettes liquids using LC-HR-MS and LC-UV %A Sophia Barhdadi %A Patricia Courselle %A Eric Deconinck %A Celine Vanhee %B 17th International Symposium on Hyphenated Techniques in Chromatography and Separation Technology (HTC-17) %I Royal Flemish Chemical Society (KVCV) and the Separation Science Group of the Royal Society of Chemistry (SSG RSC). %C Ghent, Belgium %8 18-20 May 2022 %G eng %N Royal Flemish Chemical Society (KVCV) and the Separation Science Group of the Royal Society of Chemistry (SSG RSC). %0 Thesis %D 2022 %T Development and validation of qualitative and semiquantitative methods for the analysis of phthalates and benzophenone in e-liquids %A Alban Morue %A Sophia Barhdadi %K e-cigarette %K Endocrine disruptors %K phtalates %I UCL %C Ottignies-Louvain-la-Neuve, Belgium %P 57 %8 2022 %G eng %0 Journal Article %J Drug Testing and Analysis %D 2022 %T Discrepancies between validated GC‐FID and UHPLC‐DAD methods for the analysis of Δ‐9‐THC and CBD in dried hemp flowers %A Céline Duchateau %A Cedric De Leersnijder %A Sophia Barhdadi %A Michael Canfyn %A De Braekeleer, Kris %A Eric Deconinck %K agricultural hemp %K GC-FID %K herbal product for smoking %K UHPLC-DAD %B Drug Testing and Analysis %V 14 %8 10/2022 %G eng %N 10 %R 10.1002/dta.3354 %0 Conference Proceedings %B HuisartsNu %D 2022 %T E-sigaretten: kunnen de smaken je later zuur opbreken? Analyse van smaakstoffen in vloeistoffen voor e-sigaretten %A Sophia Barhdadi %A Tamara Vanhaecke %A Eric Deconinck %K aerosol %K roken %B HuisartsNu %I HuisartsNu %V 51 %8 05/2022 %U https://www.huisartsnu.be/2022/nr3/artikel/e-sigaretten-kunnen-de-smaken-je-later-zuur-opbreken-analyse-van-smaakstoffen %N 3 %0 Generic %D 2022 %T Feasibility study of using surface enhanced Raman scattering (SERS) combined with handheld Raman spectrometer for the detection of nicotine in e-liquids %A Charlotte De Bleye %A Lise De Barsy %A Sophia Barhdadi %A Eric Deconinck %A Pierre-Yves Sacré %A Philippe Hubert %A Eric Ziemons %B GFSV Nivelles 2022 %I Groupe Français de Spectroscopie Vibrationnelle (GFSV) %C Nivelles, Belgium %8 18-22 May 2022 %G eng %N Groupe Français de Spectroscopie Vibrationnelle (GFSV) %0 Generic %D 2022 %T Identification of flavouring substances of genotoxic concern in e-liquids %A Sophia Barhdadi %A Vanhaecke, Tamara %A Birgit Mertens %A Eric Deconinck %K e-cigarette %K genotoxicity %B BfR Consumer Protection Forum "Opportunities and Risks of the e-cigarette" %I BfR %C Berlin, Germany %8 28-29 April 2022 %G eng %0 Journal Article %J LCGC Europe %D 2021 %T Development of a “Freeze-Pour” Sample Preparation Method for the GC Analysis of Semivolatile Flavouring Chemicals Present in E-cigarette Refill Liquids %A Sophia Barhdadi %A Michael Canfyn %A Sanae El Merabety %A Patricia Courselle %A Rogiers, Vera %A T Vanhaecke %A Eric Deconinck %K e-cigarettes %K flavours %K GC-MS %K genotoxicity %X

During the past decade, e-cigarettes have become increasingly popular. To guarantee their safe use and to comply with the notification requirements of the EU Tobacco Product Directive, the EU member state regulatory authorities need information about the exact composition of the e-liquids and their emissions. However, one of the challenges encountered during the analysis of e-liquids is the presence of the highly abundant e-liquid matrix components propylene glycol and glycerol. In this study, headspace gas chromatography (HS-GC) analysis is presented as an excellent method for the analysis of high volatile components in e-liquids. For the analysis of semivolatile ingredients, an additional sample preparation step is proposed based on a liquid–liquid extraction (LLE) followed by a freeze-out of the matrix components. The developed method was successfully validated in accordance with the validation requirements of ICH guidelines for the quantification of four flavourings with a potential health concern for e-cigarette users.

%B LCGC Europe %V 34 %8 01/06/2021 %G eng %N 6 %& 223 %R https://www.chromatographyonline.com/view/development-of-a-freeze-pour-sample-preparation-method-for-the-gc-analysis-of-semivolatile-flavouring-chemicals-present-in-e-cigarette-refill-liquids %0 Thesis %D 2021 %T Development of vibrational spectroscopic methods combined with chemometrics for the detection and quantification of nicotine in e-liquids. %A Lise De Barsy %A Charlotte De Bleye %A P.Y. Sacré %A Sophia Barhdadi %K Chemometrics %K e-cigarettes %K infra-red spectroscopy %K Nicotine %K RAMAN %X

E-cigarette have become a popular alternative to smoking tobacco cigarettes. They are sold in vapeshops and online. However, in Belgium, it is prohibited to import or to buy nicotine-containing e-liquids via the internet. The ban on long-distance sale implies that postal packages containing e-liquids are checked at customs. Furthermore, there is a demand of vapeshop-inspectors for on-site screening of e-liquid samples to check their compliance to the TPD i.e. non-nicotine labeled e-liquids should not contain nicotine and the maximum nicotine concentration of nicotine-labeled e-liquids should be respected (< 20mg/ml). The main objective of this paper is to develop a handheld NIR, Raman or SERS spectroscopic method combined with chemometrics (PLS and PCA) for detection and quantification of nicotine in e-liquids out of the laboratory. Raman and SERS, combined with chemometrics were proved to be promising tools for the detection and quantification of nicotine in e-liquids. However, improvement of Raman PLS model and further SERS studies with tests on a larger number of samples are still needed.

%I ULg %C Liège, Belgium %P 54 %8 2021 %G eng %0 Conference Proceedings %D 2021 %T E-cigarettes : des produits dangereux dans les e-liquides %A Olivier Corroenne %A Sophia Barhdadi %A Mathieu Capouet %K e-liquides %X

Une étude de Sciensano, l’Institut de santé publique, le démontre : des produits contenus dans certains e-liquides de cigarettes électroniques sont potentiellement et même carrément dangereux pour la santé. Pourtant, les producteurs ne sont pas toujours obligés de déclarer les composants de ces produits aux autorités publiques. Mais cela va changer …. 

Interview sur le site de rtbf: https://www.rtbf.be/info/societe/onpdp/detail_e-cigarettes-des-produits-dangereux-dans-les-e-liquides?id=10741976

%I rtbf.be %C https://www.rtbf.be/info/societe/onpdp/detail_e-cigarettes-des-produits-dangereux-dans-les-e-liquides?id=10741976 %8 16 apr 2021 %U https://www.rtbf.be/info/societe/onpdp/detail_e-cigarettes-des-produits-dangereux-dans-les-e-liquides?id=10741976 %0 Conference Proceedings %B E-liquides : fumer "bio", c'est meilleur pour la santé ? %D 2021 %T E-liquides : fumer "bio", c'est meilleur pour la santé ? %A Olivier Corroenne %A Mathieu Capouet %A Sophia Barhdadi %K Bio %K Consommateur %K e-liquides %K glycerine végétale %K Nicotine %K origine végétale %K Propylene Glycol %X

Fumer "bio" avec une cigarette électronique, est-ce meilleur pour la santé ? Les fabricants d' e-liquides qui développent des produits "bio" semblent en tout cas convaincus. 

interview sur le site web de rtbf: https://www.rtbf.be/info/societe/onpdp/detail_e-liquides-fumer-bio-c-est-meilleur-pour-la-sante?id=10754298

%B E-liquides : fumer "bio", c'est meilleur pour la santé ? %I rtbf.be %C https://www.rtbf.be/info/societe/onpdp/detail_e-liquides-fumer-bio-c-est-meilleur-pour-la-sante?id=10754298 %8 7 may 2021 %U https://www.rtbf.be/info/societe/onpdp/detail_e-liquides-fumer-bio-c-est-meilleur-pour-la-sante?id=10754298 %0 Journal Article %J Food and Chemical Toxicology %D 2021 %T Identification of flavouring substances of genotoxic concern present in e-cigarette refills %A Sophia Barhdadi %A Birgit Mertens %A Melissa Van Bossuyt %A Jolien Van de Maele %A Roel Anthonissen %A Michael Canfyn %A Patricia Courselle %A Rogiers, Vera %A Eric Deconinck %A Vanhaecke, Tamara %K (Q)SAR methodologies %K e-cigarettes %K genotoxicity %K mutagenicity %X

E-cigarettes have become very popular, a trend that has been stimulated by the wide variety of available e-liquid flavours. Considering the large number of e-liquid flavours (>7000), there is an urgent need to establish a screening strategy to prioritize the flavouring substances of highest concern for human health. In the present study, a prioritization strategy combining analytical screening, in silico tools and literature data was developed to identify potentially genotoxic e-liquid flavourings. Based on the analysis of 129 e-liquids collected on the Belgian market, 60 flavourings with positive in silico predictions for genotoxicity were identified. By using literature data, genotoxicity was excluded for 33 of them whereas for 5, i.e. estragole, safrole, 2-furylmethylketon, 2,5-dimethyl4-hydroxyl-3(2H)-furanone and transhexanal, there was a clear concern for in vivo genotoxicity. A selection of 4 out of the remaining 22 flavourings was tested in two in vitro genotoxicity assays. Three out of the four tested flavourings induced gene mutations and chromosome damage in vitro, whereas equivocal results were obtained for the fourth compound. Thus, although there is a legislative framework which excludes the use of CMR compounds in e-liquids, flavourings of genotoxic concern are present and might pose a health risk for e-cigarette users.

%B Food and Chemical Toxicology %V 147 %8 jan 2021 %G eng %N 111864 %R 10.1016/j.fct.2020.111864 %0 Journal Article %J Nicotine & Tobacco Research %D 2021 %T Impact of the revised European Tobacco Product Directive on the quality of e-cigarette refill liquids in Belgium %A Sophia Barhdadi %A Moens, Goedele %A Michael Canfyn %A Celine Vanhee %A Bart Desmedt %A Patricia Courselle %A Rogiers, Vera %A Vanhaecke, Tamara %A Eric Deconinck %K e-cigarettes %X

Introduction

Since its introduction, the e-cigarette has become a commonly used consumer product. In this study, we investigate whether regulatory changes had an impact on the quality of refill liquids (e-liquids) available on the Belgian market through analysis of their chemical composition. Hence, the nicotine concentration accuracy was investigated in samples before, during and after the implementation of the revised Tobacco Product Directive (TPD) as an indicator of good manufacturing practices. This is, however, not enough to assure the quality. Therefore, extra criteria were also assessed based on TPD requirements.

Methods

By using in-house validated methods, a total of 246 e-liquids purchased prior (2013-2015), during (2016) and after (2017-2018) the implementation of the TPD revisions, were analyzed for the presence of nicotine, nicotine-related impurities, volatile organic compounds (VOCs), caffeine and taurine, and the flavours diacetyl and acetylpropionyl.

Results

Although not all manufacturers managed to produce and label their products accurately, nicotine labelling discrepancies have decreased over time. Moreover, also the number of e-liquids, containing high risk VOCs (10% in 2016 versus none of the samples in 2017-2018), caffeine (16% in 2017 versus 5% in 2018) and diacetyl and acetylpropionyl (55% in 2017 versus 27% in 2018 of sweet flavoured samples) diminished over time.

Conclusion

Our results demonstrate that the overall quality of the e-liquids has improved after the implementation of the revised TPD. However, the results also show that periodic quality control might be required to ensure further compliance to the TPD.

Implications

This study clearly demonstrates that the implementation of the revised TPD has improved the quality of the e-liquids on the Belgian market. However, there are still e-liquids that are not in agreement with the TPD due to nicotine concentration label discrepancies, presence of e-liquid impurities and controversial flavours diacetyl and acetylpropionyl or the additive caffeine.

%B Nicotine & Tobacco Research %8 jan 2021 %G eng %R 10.1093/ntr/ntaa023 %0 Journal Article %J Archives of Toxicology %D 2021 %T Toxicity assessment of flavour chemicals used in e-cigarettes: current state and future challenges %A Sophia Barhdadi %A Rogiers, Vera %A Eric Deconinck %A Vanhaecke, Tamara %K e-cigarettes %K flavours %K toxicity %X

NA

%B Archives of Toxicology %V 95 %8 08/01/2021 %G eng %N 8 %R 10.1007/s00204-021-03080-6 %0 Thesis %D 2020 %T Chemical and toxciological characterization of e-liquid cigarettes %A Sophia Barhdadi %A Eric Deconinck %K E-sigaret %X

The popularity of the electronic cigarette (e-cigarette) has increased significantly in the past decade. In Belgium, the implementation of the revised European Tobacco Products Directive (TPD) in 2014 marked a turning point for this phenomenon. Prior to this, the use of the e-cigarette was not yet mainstream, as only nicotine-free e-cigarettes were allowed on the market. However, as a result of the legislative changes, nicotine-containing e-cigarettes became freely available on the market and ‘vapeshops’ skyrocketed since then. As the number of e-cigarette users increased, so did the media coverage about the benefits and dangers of the e-cigarette, whether scientifically substantiated or not. To assure public health, scientific research about the safety and quality of the e-cigarette is of great importance. The objective of this PhD thesis was therefore to first determine the chemical composition of the liquids used in e-cigarettes (e-liquid) and next to investigate toxicological aspects of flavouring substances present in e-liquid refills.

First, a comprehensive literature search was performed to obtain an overview about the chemical composition of the e-liquids and the analytical methods used for their detection. Although the analytical methods used in these studies have not always been well validated and thus the results of these studies need to be critically examined; three main problems could be uncovered: (1) the content of nicotine in the e-liquids often does not correspond to the claimed concentration, (2) there is a significant presence of hazardous impurities and contaminants in the e-liquids and (3) food flavourings (diacetyl and acetylpropionyl) which are toxic when inhaled are also present.

In order to analyse the composition of the e-cigarettes and to check the e-liquids for the abovementioned issues, alternative methods were developed for the quantitative determination of nicotine and its related impurities (HPLC-DAD) and for the flavours diacetyl and acetylpropionyl (HS/GC-MS). Also, screening methods were developed for the identification of volatile organic compounds (HS/GC-MS) and the additives taurine (LC-MS/MS) and caffeine (GC-MS). Subsequently, the influence of the revised TPD on the quality of e-liquids available on the Belgian market was investigated using these developed methods. A total of 246 e-liquids were purchased before (2013-2016), during (2016) and after (2017-2018) the implementation of the revised TPD. The samples were examined for the presence of nicotine, nicotine-related impurities, volatile organic compounds, caffeine, taurine and the harmful flavours diacetyl and acetylpropionyl. In general, the legislative changes have had a positive effect on the quality of e-liquids: the results of our study show that the quality of e-liquids has improved following the implementation of the revised TPD. Indeed, in recent years, there have been significantly fewer discrepancies between the effective nicotine content and the claimed concentration. No hazardous volatile organic compounds were found in the 2017-2018 samples compared to the samples before the TPD. In 2018, 5% of the samples contained caffeine, compared to 16% in 2017. The food flavours diacetyl and acetylpropionyl were still present in e-liquids with a sweet, buttery taste such as cake, caramel, popcorn (55% in 2017 compared to 27% in 2018).

Next, as a test case, the risk of inhaling diacetyl present in e-liquids was investigated. An adapted risk assessment methodology for intentional inhalation of substances through the e-cigarette was applied. This exercise showed that there is no risk for systemic toxicity related to diacetyl vapours. However, the risk for local lung toxicity (lung tissue lesions associated with chronic pulmonary bronchiolitis obliterans) could not be excluded in case of repeated exposure to diacetyl through e-cigarette use.

In the final experimental part of the thesis, we focused on the identification of potential genotoxic flavouring substances in e-liquids through the use of non-animal methodologies. As such, 807 flavouring substances were identified in 129 e-liquids using complementary HS-GC MS methods. In a first step, all these substances were screened for genotoxicity using qualitative and quantitative in silico models. In total, potential genotoxicity activity was predicted for 44 flavourings. Based on information from European databases, genotoxicity could be confirmed for five of these flavourings (estragole, safrole, 2-furylmethylketone, 2,5-dimethyl-4-hydroxyl-3(2H)-furanone and transhexanal). Genotoxicity could be excluded for 23 flavourings. For the remaining 16 flavourings, insufficient information on their genotoxicity was present. For four of these flavourings, a commercial standard was available and thus could be tested in vitro using an Ames- and micronucleus test. One of the four substances was only slightly positive in the micronucleus test (b-hellandrene), while for isoledene, 2,3-butanedione and 2,3-pentanedione a clear positive result was obtained in at least one of the two in vitro tests.

Finally, in order to minimise potential health risks imposed by the use of e-cigarettes, some recommendations are suggested to further amend the current e-cigarette legislation.

%I Vrije Universiteit Brussel (VUB) %C Brussels, Belgium %P 214 %8 09/2020 %G eng %0 Generic %D 2019 %T Development of a sample preparation method for the GC-analysis of e-cigarette refill liquids %A Sophia Barhdadi %A Michael Canfyn %A Bart Desmedt %A Sanae El Merabety %A Patricia Courselle %A Rogiers, Vera %A Tamara Vanhaecke %A Eric Deconinck %X

Since its introduction more than 10 years ago, the e-cigarette has become a commonly used consumer product. To guarantee the users safety, analytical characterization of the refill liquids (e-liquids) used for e-cigarettes is essential. Different techniques have been used for the qualitative and quantitative chemical characterization of e-liquids of which gas-chromatography is the most often used technique as e-liquids mainly consist out of (semi)-volatile ingredients (i.e. nicotine and flavourings) dissolved in a propylene glycol and glycerol matrix. The e-liquid matrix is viscous and greasy which may result in a faster deterioration of the GC-columns and deactivate the interaction with the active groups. To overcome this issue, a proper sample preparation is needed, to improve the life span of the column and reduce the total number of cuts in the GC-column.

The aim of our study is to quantify potential harmful flavourings used in e-cigarettes using GC-method with an appropriate sample preparation. The group of flavourings are divided in two groups: high and low semi-volatiles. High volatile flavouring group contains the flavourings diacetyl and acetylpropionyl. The low and semi-volatiles contain potential genotoxic flavourings, selected through in-silico genotoxicity screening of 436 identified components in 77 e-liquid samples. These components are pulegone, estragole, 5-methylfurfural, 2-furylmethylketon, methylnaphthalene, trans-menthone and trans-2-hexanal.

For the high volatiles flavourings headspace is considered to limit the transfer of the matrix to the column. The headspace temperature was chosen in  order to obtain an optimal transfer of the target components to the headspace with minimal transfer of the matrix components. The e-liquid was dissolved in water, to shift the equilibrium of the target components towards the headspace and to enhance the retention of the matrix components. The optimal headspace temperature was set at 85°. For the low and semi volatiles, full evaporation conditions (145°C) of the headspace were considered. In this case a sample clean-up is needed to avoid transfer of the matrix components to the column. Different sample clean up techniques were tested. Finally the liquid-liquid extraction (LLE) with freeze out using flash cooling technique was optimized. This sample preparation techniques can also be used with other GC-injection techniques. Both methodologies were further optimized and validated for quantification of the target components using matrix-matched calibration

The sample preparation of most quantification methods for e-liquids only consisted of simple dilute and shoot methodologies. In this study, we successfully developed a clean-up technique to eliminate most of the matrix components. The sample preparation of LLE with freeze out using flash cooling technique is a sample preparation which could be applied and optimized for other target components in e-liquids.

%B Euroanalysis XX - 1-5 September 2019, Istanbul %8 2019 %G eng %0 Thesis %D 2019 %T Genotoxic evaluation of the liquids present in electronic cigarettes %A Britt Buffaerts %A Birgit Mertens %A Sophia Barhdadi %X

[Background]  The electronic cigarette (e-cigarette) is a battery-powered device that vaporizes liquid for inhalation by the user. In general, the e-cigarette is perceived as being healthier than the conventional cigarette because no combustion process (and subsequently no formation of hazardous substances related to this process) occurs. However, the absence of the combustion process does not directly imply that the e-cigarette is a healthy substitute compared to the tobacco cigarette. While some studies indicate that the e-cigarette may be up to 95% healthier than the conventional cigarette, an important amount of hazardous substances are still present in the e-liquid, albeit at lower concentrations. Exposure to e-liquid substances has been associated with molecular changes, carcinogenicity and diseases such as heart malfunctions, delayed cellular differentiation and impaired immunological responses in animal models. Whether these findings are also relevant to humans remains unclear.

[Aim]  The genotoxic potential of flavouring substances present in e-cigarettes was studied using animal-free approaches. In addition, the applicability of the Ames test and the in vitro micronucleus test to evaluate the genotoxic potential of e-liquids mixtures was investigated.

[Methods]  The study was performed with flavouring substances that have previously been identified in e-liquids. First, the genotoxic potential of these compounds was assessed using in silico prediction software Derek and Sarah Nexus. For substances that showed a structural alert for genotoxicity in one of the models, genotoxicity data (if available) were collected from the databases of the European Food Safety Authority and European CHemicals Agency. In a next step, compounds for which no data were found and that were commercially available were studied in the Ames test and the in vitro micronucleus test (i.e. b-phellandrene, 2,3-pentanedione). However, for the majority of the compounds, no standard could be obtained and consequently, the Ames test and the in vitro micronucleus test were performed on the e-liquid mixtures. In order to assess the applicability of the in vitro tests for the e-liquid mixtures, three 2,3-pentanedione-containing e-liquids (i.e. Nutella Shake, Hyprtonic Mercedes, Miller’s Chocolate) and an e-liquid containing no substances with structural alerts for genotoxicity (i.e. Dark Turtle) were first tested. In a next step, two e-liquids containing components with a structural alert for genotoxicity but without in vitro or in vivo data (i.e. Ice Ice Baby, Candy Shop) were studied in the Ames test and the in vitro micronucleus test.

[Results and discussion]  Based on the predictions obtained with the in silico models and the availability of genotoxicity data, 28 compounds detected in e-liquids were selected for in vitro genotoxicity testing. However, only two of these compounds were commercially available. b-phellandrene showed a slightly genotoxic effect in the in vitro micronucleus test in the presence of S9 metabolic fraction but was clearly negative in the Ames test. In contrast, 2,3-pentanedione induced a clear dose-dependent genotoxic effect, both in the Ames test and the in vitro micronucleus test. The effect did not require metabolic activation. All three 2,3-pentadione-containing e-liquids showed a negative result in the Ames test. However, they all induced a positive effect in the in vitro micronucleus test that was clearly more pronounced than the effect induced by the propylene glycol/glycerol matrix. Dark Turtle, an e-liquid containing solely nicotine, showed no or little additional genotoxic effect when compared to the matrix. This e-liquid was also negative in the Ames test. The results indicate that e-liquids containing potentially genotoxic compounds can be picked up in the in vitro micronucleus test. Interestingly, out of the two e-liquids containing components with a structural alert for genotoxicity, one was clearly positive whereas the other was negative in the in vitro micronucleus test. Both were also negative in the Ames test.

[Conclusion]  Known and unknown potentially genotoxic compounds can be present in e-liquids. Furthermore, genotoxic effects of e-liquid mixtures can be picked up with the in vitro micronucleus test. Consequently, this test could be useful for ranking e-liquids based on their genotoxic concern. However, further research should be conducted.

%P 61 %8 2019 %G eng %0 Generic %D 2019 %T Impact of the revised European Tobacco Product Directive on the quality of e-cigarette refill liquids in Belgium %A Sophia Barhdadi %A Moens, Goedele %A Michael Canfyn %A Celine Vanhee %A Bart Desmedt %A Patricia Courselle %A Rogiers, Vera %A Vanhaecke, Tamara %A Eric Deconinck %K e-cigarettes %X

Introduction: Since its introduction more than 10 years ago, the e-cigarette has become a commonly used consumer product. This success has led in 2014 to the revision of the European Tobacco Product Directive (TPD) which came to force by the end of 2016, since then also containing mandatory rules to assure the quality and safety of electronic nicotine delivery systems. In this study, we investigate whether these regulatory changes had an impact on the quality of refill liquids (e-liquids) available on the Belgian market through analysis of their chemical composition.

 

Methods: By using in-house validated methods, a total of 246 e-liquids purchased prior (2013-2015), during (2016) and after (2017-2018) the implementation of the TPD revisions, were analyzed for the presence of nicotine, nicotine-related impurities, volatile organic compounds (VOCs), the additives caffeine and taurine, and the flavours diacetyl and acetylpropionyl.

 

Results: Although not all manufacturers manage to produce and label their products accurately, nicotine labelling discrepancies have decreased over time. Before the revised TPD came into force, almost half of the samples was not conform in contrast to less than 15% non-conformities observed in the period 2017-2018. Moreover, also the number of e-liquids, containing high risk VOCs (10% in 2016 versus none of the samples in 2017-2018), caffeine (16% in 2017 versus 5% in 2018) and diacetyl and acetylpropionyl (55% in 2017 versus 27% in 2018 of sweet flavoured samples) diminished over time.

 

Conclusion: Our results demonstrate that the overall quality of the e-liquids has improved after the implementation of the revised TPD. However, the results also show that periodic quality control might be required to ensure further compliance to the TPD.

 

Implications: This study clearly demonstrates that the implementation of the revised TPD has improved the quality of the e-liquids on the Belgian market. However, there are still e-liquids that are not in agreement with the TPD due to nicotine concentration label discrepancies, presence of e-liquid impurities and of the controversial flavours diacetyl and acetylpropionyl or the additive caffeine.

%B 20th Forum of Pharmaceutical Sciences - Brussels - 20 May 2019 %8 2019 %G eng %0 Journal Article %J Journal of Pharmaceutical and Biomedical Analysis %D 2019 %T A simple dilute-and-shoot method for screening and simultaneous quantification of nicotine and alkaloid impurities in electronic cigarette refills (e-liquids) by UHPLC-DAD %A Sophia Barhdadi %A Bart Desmedt %A Patricia Courselle %A Rogiers, Vera %A Vanhaecke, Tamara %A Eric Deconinck %K accuracy profiles %K e-cigarettes %K Nicotine %K nicotine-impurities %K UHPLC-DAD %X

The electronic cigarette (e-cigarette) has emerged as a popular alternative to the traditional hazardous tobacco cigarette. The substantial increase in e-cigarette use also urgently calls for controlling the quality of e-cigarette refill liquid products (e-liquids). Currently, the most important quality indicator of e-liquid products is the quantification of nicotine and its related impurities. Although different methods have been published to measure nicotine and impurity levels, the majority of them use a targeted LC-MS/MS approach. There is, however, a need for more robust quantification methods that are easy to implement in most control (industrial and governmental) laboratories. Therefore, in this study, a simple dilute-and-shoot UHPLC-DAD method has been developed and validated for the simultaneous quantification of nicotine and its alkaloid impurities in electronic cigarette refills. An optimal separation of the alkaloids was achieved in a runtime of 11 min. The method was successfully validated using the “total error” approach in accordance with the validation requirements of ISO-17025. During this validation, interference between the target components and a number of popular flavouring compounds such as vanillin, maltol, ethylacetate, etc. could be excluded. In addition, small changes to the column temperature, pH and molar concentration of the mobile phase buffer were deliberately introduced in order to assess the robustness of the method. Only a slightly different outcome between the newly developed UV-detection method and the targeted MS approach was found, due to the sensitivity of the different detection techniques. However, in the context of quality control of nicotine related impurities, for which the European Pharmacopoeia limits are currently applied, the sensitivity of the UHPLC-DAD method was found to be within the acceptable range. Despite the somewhat lower selectivity of the newly developed UV-detection technique versus a targeted LC-MS/MS approach, it may be concluded that this method is a suitable alternative for quality control purposes.

%B Journal of Pharmaceutical and Biomedical Analysis %V 169 %8 30 May 2019 %G eng %N 169 %& 225 %R 10.1016/j.jpba.2019.03.002 %0 Generic %D 2018 %T Chemical characterization of electronic cigarette refills (e-liquids) in Belgium %A Sophia Barhdadi %A Michael Canfyn %A Moens, Goedele %A Celine Vanhee %A Bart Desmedt %A Patricia Courselle %A Rogiers, Vera %A Vanhaecke, Tamara %A Eric Deconinck %K additives %K e-cigarettes %K GC %K impurities %K LC %K Nicotine %B 29th International Symposium on Pharmaceutical and Biomedical Analysis %I Journal of Pharmaceutical and Biomedical Analysis %C Leuven, Belgium %8 9/9/2018 %G eng %0 Generic %D 2018 %T Identification of Flavouring Substances of Genotoxic Concern Present in E-Cigarette Refills %A Sophia Barhdadi %A Birgit Mertens %A Melissa Van Bossuyt %A Michael Canfyn %A Patricia Courselle %A Rogiers, Vera %A Eric Deconinck %A Vanhaecke,T. %K e-cigarettes %K flavourings %K genotoxicity %X

Over the last years, the popularity of electronic e-cigarettes has increased significantly. An important contributor to this trend is the availability of a wide variety of flavours used in e-liquid refills. However, the role of these flavouring components in the potential toxicity of e-cigarette vapours remains unclear. Considering the large number of e-liquid flavours available on the market (> 7000), there is an urgent need to establish an efficient screening strategy to prioritize the substances of highest concern for human health. In this context, genotoxicity is a key (toxicological) endpoint as it is related to a broad range of adverse human health effects including cancer. Therefore, in this study, a prioritization strategy based on a combination of analytical screening, in silico prediction and literature consultation was developed for identifying potentially genotoxic substances in e-liquid flavours.

77 e-liquids, representative for the different flavour categories, were collected on the Belgian market and screened for their chemical composition using GC-MS. By using the National Institute of Standards and Technology (NIST) research library, 436 individual components could be identified. Next, the genotoxic potential of these individual components was investigated in silico with two complementary (quantitative) structure-activity relationship ((Q)SAR) models (Derek Nexus, Sarah Nexus). In total, 57 flavouring components were identified with a structural alert for genotoxicity in at least one of the two (Q)SAR models. For these substances, genotoxicity data was collected from previous European safety evaluations in different regulatory domains (e.g. by the European Chemical Agency (ECHA) and the European Food Safety Authority (EFSA)). Genotoxicity could be excluded for only 12 of the 57 components, whilst for 2 of them there is a clear concern for genotoxic potential. Data for the remaining components was missing or ambiguous and hence additional toxicological data is required in order to be able to exclude genotoxic potential.

The above findings indicate that the use of flavoring components might thus pose a potential health risk for e-cigarette users. Further research might explore to which extent these flavouring substances are transferred from the e-liquid into the e-cigarette vapours.

%B EUROTOX 2018 %I Toxicology Letters %C Brussels, Belgium %8 05/09/2018 %G eng %0 Thesis %D 2018 %T Ontwikkeling en validatie van een HS-GC-MS/MS methode voor de bepaling van potentieel genotoxische smaakstoffen in e-vloeistoffen. %A Sanae El Merabety %A Sophia Barhdadi %A Eric Deconinck %K undefined %I Vrije Universiteit Brussel %C Brussels %P 50 %8 14/06/2018 %G eng %0 Journal Article %J J.Pharm.Biomed.Anal. %D 2017 %T Development and validation of a HS/GC-MS method for the simultaneous analysis of diacetyl and acetylpropionyl in electronic cigarette refills %A Sophia Barhdadi %A Michael Canfyn %A Patricia Courselle %A Rogiers,V. %A Vanhaecke,T. %A Eric Deconinck %K Analyses %K analysi %K analysis %K approach %K AS %K Belgium %K bias %K Brussels %K Control %K Development %K electronic %K EVALUATION %K food %K health %K identify %K Institute %K IS %K journal %K measurement %K Medicine %K method %K methodology %K methods %K ON %K profile %K public %K public health %K Public-health %K Quality %K Quality Control %K Quantification %K SAFETY %K Sample %K Samples %K SCREENING %K study %K tobacco %K toxicity %K Toxicology %K use %K VALIDATION %X

The use of e-cigarettes as alternative for tobacco cigarettes has become increasingly popular, even though their safety has not yet been scientifically established. One of the frequently raised concerns is the potential toxicity of certain flavours present in the e-liquids, such as diacetyl and acetylpropionyl. It is therefore important to be able to identify and quantify both compounds. Numerous analytical methods have been published for determining e-liquid compositions, but concerns exist with respect to the lack of analytical evaluation. Hence in this study, a new HS/GC-MS-based method was developed for the screening and quantification of diacetyl and acetylpropionyl in e-liquids. This method was fully validated using the 'total error' approach. The LOQ of the analytical method was 5ppm for diacetyl and acetylpropionyl. The obtained accuracy profiles show that the beta-expectation tolerance intervals did not exceed the acceptance limits of+/-10%, meaning that 95% of future measurements will be included in the [-10%, 10%] bias limits. As proof of applicability, the validated method was successfully applied on a small set of e-liquid samples, indicating that this methodology could be used for routine quality control analyses of e-liquids

%B J.Pharm.Biomed.Anal. %V 142 %P 218 - 224 %8 4/5/2017 %G eng %1 2682 %& 218 %R S0731-7085(16)31467-4 [pii];10.1016/j.jpba.2017.04.050 [doi] %0 Journal Article %J J Pharm Biomed Anal %D 2016 %T Discriminating nicotine and non-nicotine containing e-liquids using infrared spectroscopy. %A Eric Deconinck %A Bothy, J L %A Sophia Barhdadi %A Patricia Courselle %K Belgium %K Electronic Cigarettes %K Nicotine %K Spectroscopy, Near-Infrared %X

In a few countries, including Belgium, nicotine-containing e-cigarettes and e-liquids are considered medicines, and therefore cannot freely be sold, but should be distributed in a pharmacy. The fact that in the neighbouring countries these products are freely available, poses a problem for custom personnel, the more the nicotine content of the products is not always labelled, especially when they are bought through internet. Therefore there is a need for easy-to-use equipment and methods to perform a first on site screening of intercepted samples, both for border control as to check label compliance of the sample. The use of attenuated total reflectance-infrared spectroscopy (ATR-IR) and near infrared spectroscopy (NIR), combined with chemometrics was evaluated for the discrimination between nicotine containing and non-nicotine containing samples. It could be concluded that both ATR-IR and NIR could be used for the discrimination when combined with the appropriate chemometric techniques. The presented techniques do not need sample preparation and result in models with a minimum of false negative samples. If a large enough training set can be established the interpretation can be fully automated, making the presented approach suitable for on-site screening of e-liquid samples.

%B J Pharm Biomed Anal %V 120 %P 333-41 %8 2016 Feb 20 %G eng %1 http://www.ncbi.nlm.nih.gov/pubmed/26771132?dopt=Abstract %R 10.1016/j.jpba.2015.12.054