Simultaneous Determination of Tobacco Alkaloids, Tobacco-Specific Nitrosamines, and Solanesol in Consumer Products Using UPLC–ESI-MS/MS

Firstly Electrochemical Examination of Myosmine at Glassy Carbon Electrode: Sensitive Determination in Tobacco Leaves by Differential Pulse Voltammetry

In this study, the electrochemical properties of myosmine, one of the tobacco alkaloids, were investigated for the first time using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques on glassy carbon electrode (GCE). Using GCE with CV technique, it gave an irreversible reduction peak with diffusion control at about −1.38 V in Britton‐Robinson (BR, pH 12.0) medium. A good linear relationship between concentration and current in the range of 0.5 μM–3.5 μM in BR (pH 12.0) medium on GCE with DPV technique [Ip(μA)=0.847 C(μM)+0.114, r=0.995, n=7] has been observed. The proposed method has been successfully applied to tobacco leaves.

Chiral determination of nornicotine, anatabine and anabasine in tobacco by achiral gas chromatography with (1S)-(-)-camphanic chloride derivatization: Application to enantiomeric profiling of cultivars and curing processes

The alkaloid enantiomers are well-known to have different physiological and pharmacological effects, and to play an important role in enantioselectivity metabolism with enzymes catalysis in tobacco plants. Here, we developed an improved method for simultaneous and high-precision determination of the individual enantiomers of nornicotine, anatabine and anabasine in four tobacco matrices, based on an achiral gas chromatography-nitrogen phosphorus detector (GCNPD) with commonly available Rtx-200 column using (1S)-(-)-camphanic chloride derivatization. The method development consists of the optimization of extraction and derivatization, screening of achiral column, analysis of the fragmentation mechanisms and evaluation of matrix effect (ME). Under the optimized experimental conditions, the current method exhibited excellent detection capability for the alkaloid enantiomers, with coefficients of determination (R2) > 0.9989 and normality test of residuals P > 0.05 in linear regression parameters. The ME can be neglected for the camphanic derivatives. The limit of detection (LOD) and limit of quantitation (LOQ) ranged from 0.087 to 0.24 μg g - 1 and 0.29 to 0.81 μg g - 1, respectively. The recoveries and within-laboratory relative standard deviations (RSDR) were 94.3%~104.2% and 0.51%~3.89%, respectively. The developed method was successfully applied to determine the enantiomeric profiling of cultivars and curing processes. Tobacco cultivars had a significant impact on the nornicotine, anatabine, anabasine concentration and enantiomeric fraction (EF) of (R)-nornicotine, whereas the only significant change induced by the curing processes was an increase in the EF of (R)-anabasine.

Progress in the pretreatment and analysis of N-nitrosamines: an update since 2010

As highly toxic substances, N-nitrosamines (NAs) have been proved to cause carcinogenesis and mutagenesis in humans. Therefore, to carefully monitor safety and preserve human health, the development of rapid, accurate, and high-sensitivity determination methods of NAs is of substantial importance. This review provides a current-status comprehensive summary of the pretreatment and determination methods of NAs in various samples since 2010. Common pretreatment methods that have been used to extract and purify targets include solid-phase extraction, liquid-liquid extraction and various microextraction methods, such as solid-phase microextraction and liquid-phase microextraction, among others. Determination methods include liquid chromatography, gas chromatography, supercritical fluid chromatography and electrochemical methods, among others. In addition, we discuss and compare the advantages and disadvantages of various pretreatment and analytical methods and examine the prospects in this area.

Use of autoclave extraction-supercritical fluid chromatography/tandem mass spectrometry to analyze 4-(methylintrosamino)-1-(3-pyridyl)-1-butanone and N'-nitrosonornicotine in tobacco

4-(methylintrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) are the most prevalent and toxic tobacco specific nitrosamines (TSNAs). Due to their carcinogenicity, knowledge of the composition of NNK and NNN in tobacco is necessary. Herein, a sensitive and rapid method, which employs autoclave extraction-supercritical fluid chromatography/tandem mass spectrometry (SFC-MS/MS), has been developed for the analysis of NNK and NNN in tobacco. Both water-soluble and matrix-bound NNK and NNN were extracted with 100 mM ammonium acetate in an autoclave (130 °C, 4 h), and the aqueous extract was subjected to solvent replacement prior to SFC-MS/MS analysis. NNK and NNN were effectively separated within 5 min by using supercritical CO2 as the main mobile phase coupled with a co-solvent of methanol. Excellent linearity was obtained with coefficients of determination (R2) greater than 0.9997 in the range of 1-160 ng/mL and 5-800 ng/mL for NNK and NNN, respectively. The recoveries were in the range of 92.5-110.0% at different spiked levels of real samples. 12 tobacco samples which include 3 typical tobacco varieties of burley, flue-cured, and oriental tobaccos had been analyzed, and the fraction of matrix-bound NNK was determined as well. In addition, a comparison between the proposed SFC-MS/MS method and a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) internal standard method was conducted. Both techniques exhibit comparable analysis results, but peak splitting of NNN was observed by LC-MSMS due to the existence of E/Z isomers, while SFC-MS/MS offers great improvement through elution condition optimization, demonstrating the applicability of SFC-MS/MS as an alternative tool for NNK and NNN analysis.

Simultaneous enrichment and analysis of tobacco alkaloids by microextraction coupled with mass spectrometry using a poly (N-isopropyl-acrylamide-co-divinyl-benzene-co-N, N'-methylene diacrylamide) monolithic column

Herein, we realized the simultaneous online detection of six tobacco alkaloids (TAs) by in-tube solid-phase microextraction (In-tube SPME) coupled with mass spectrometry by a rapid, sensitive, and matrix effect-free method requiring no chromatographic separation and only minimal sample pre-treatment. A poly (N-isopropylacrylamide-co-divinylbenzene-co-N, N'-methylenediacrylamide) [Poly (NIPAAm-co-DVB-co-MBAA)] monolithic column was designed according to the chemical structures of selected TAs and used as an extraction medium engaging in hydrophobic, π-π, and hydrogen bonding interactions with analytes, allowing them to be effectively extracted. A number of important parameters were systematically optimized to achieve maximal extraction efficiency. The ion intensity of the TAs signals obtained by in-tube SPME-MS were higher than the direct MS mode by about 400 folds with the signal-to-noise ratio improved by 2-7 folds. The detection limits of the six TAs were determined as 1.99-4.06 ng g^-1, with good linearity with correlation coefficients exceeding 0.99 obtained under optimal extraction conditions. Besides, TA recoveries in cigarette tobacco spiked at three concentration levels were in the range of 76.4-100.2%, and the corresponding RSDs (n = 5) were obtained as 4.32-7.16%. The extraction performance of the poly (NIPAAm-co-DVB-co-MBAA) monolithic column was well reproducible, with intra- or inter-day precision RSDs determined not to exceed 7.38%. Finally, no marked matrix effects were observed when the developed method was applied to the analysis of both high-abundance and trace-level TAs in practical samples, and the above technique was therefore concluded to be well suited for the detection of TAs in cigarette tobacco or other products.

Analytical Method for Measurement of Tobacco-Specific Nitrosamines in E-Cigarette Liquid and Aerosol

An experimental method was developed and validated for the collection and analysis of tobacco-specific nitrosamines (TSNAs) that are present in electronic cigarette (EC) liquid or are released from aerosol samples using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system. As part of this study, the relative recovery of four target TSNAs was assessed by spiking standards in a mixture of propylene glycol and vegetable glycerin. Recovery was assessed against two major variables: (1) the chemical media (solution) selected for sample dilution (acetonitrile [ACN] vs. ammonium acetate [AA]) and (2) the type of sampling filter used (Cambridge filter pad [CFP] vs. quartz wool [QW] tube). The average recovery of TSNAs in terms of variable 1 was 134 ± 22.1% for ACN and 92.6 ± 8.27% for AA. The average recovery in terms of variable 2 was 83.4 ± 7.33% for QW and 58.5 ± 12.9% for CFP. Based on these conditions, the detection limits of N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), and N′-nitrosoanabasine (NAB) were calculated as 4.40, 4.47, 3.71, and 3.28 ng mL−1, respectively. The concentration of TSNAs in liquid and aerosol samples of six commercial EC solutions was measured as below the detection limit.

New shape-selectivity discovered on graphene-based materials in catching tobacco specific nitrosamines

New shape-selectivity of graphene-based materials was discovered on this article. To explore the new selectivity, the structure and surface state of graphene and carbon nanotube were examined firstly, and their specific selectivity was verified and was compared with that of ZSM-5 zeolite in aqueous solutions of tobacco specific nitrosamines (TSNA) along with dyes. These two adsorbents trapped about 55% and 70% of 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) but only 3% of N'-nitrosonornicotine (NNN) in solution, having an obvious selectivity for the former, due to its stronger interaction with graphene. NNK on graphene sheet obtained more electrons (0.015 e) and owned larger adsorption energy (15.63 kcal mol-1) than that of NNN (0.003 e, 9.19 kcal mol-1), according to theoretical calculation and FTIR results. More 95 or 136 mg g -1 acid red 88 than methyl orange was captured by graphene or carbon nanotube, demonstrating this special and abnormal selectivity again. With new selectivity, graphene showed a higher capacity (6.9%) and shorter adorption equilibrium time (5 min) for TSNA than the typical selecive sorbent ZSM-5 zeolite (1.7% and 20 min) in tobacco solution but kept the similar selctivity to NNK, paving a new way to control the carcinogens like TSNA in environment.