Optimization of a Differential Ion Mobility Spectrometry–Tandem Mass Spectrometry Method for High-Throughput Analysis of Nicotine and Related Compounds: Application to Electronic Cigarette Refill Liquids

Abstract

Fast market penetration of electronic cigarettes is leading to an exponentially growing number of electronic refill liquids with different nicotine contents and an endless list of flavors. Therefore, rapid and simple methods allowing a fast screening of these products are necessary to detect harmful substances which can negatively impact the health of consumers. In this regard, the present work explores the capabilities of differential ion mobility spectrometry coupled to tandem mass spectrometry for high-throughput analysis of nicotine and 11 related compounds in commercial refill liquids for electronic cigarettes. The influence of main factors affecting the ion mobility separation, such as modifier types and concentration, separation voltage, and temperature, was systematically investigated. Despite small molecular weight differences among the studied compounds, a good separation was achieved in the ion mobility cell under the optimized conditions, which involved the use of ethanol as a polar gas-phase chemical modifier. Indeed, differential ion mobility was able to resolve (resolution >4) nicotine from its structural isomer anabasine without the use of any chromatographic separation. The quantitative performance of the proposed method was then evaluated, showing satisfactory precision (RSD ≤ 16%) and recoveries ranging from 85 to 100% for nicotine, and from 84 to 126% for the rest of the target analytes. Several commercial electronic cigarette refill liquids were analyzed to demonstrate the applicability of the method. In some cases, significant differences were found between labeled and measured levels of nicotine. Anatabine, cotinine, myosmine, and nornicotine were also found in some of the analyzed samples.

Targeted isolation of sulfur-containing metabolites from Lsr2-deletion mutant strain of Streptomyces roseosporus

“…The product ions at m/z 157.0761 and 130.0652 were attributed to the characteristic fragment of dipyridyl derivatives, 12 and the mass difference between peaks 17 and 18 was m/z 182.0712 and 185.0707 units for cyano-substituted dipyridyl and aldehydesubstituted dipyridyl, respectively, suggesting the existence of new sulfur-containing compounds. 12 The similar investigation was applied to all 22 new peaks. As a result, eight target peaks (5,9,15,16,17,18, 20a and 21) were considered as unknowns of interest.…”

“…Herein, we report the isolation and structure elucidation of six new sulfur-containing compounds, pyrismycins A-F (1-6), with seven known analogues (7)(8)(9)(10)(11)(12)(13), from the Lsr2-deletion (DSrlsr2) mutant strain of S. roseosporus. In this research, UPLC-QTOF-MS/MS, a successful tool for dereplication purposes, 10 was used to identify sulfur-containing metabolites from the DSrlsr2 strain, with present in the wild-type (WT) strain, and then used to guide the isolation work.…”

E-cigarette Product Characteristics and Subsequent Frequency of Cigarette Smoking

“…Participants who reported using e-cigarettes without nicotine may also be exposed to nicotine; numerous studies have shown that solutions labeled "nicotine free" may contain nicotine. [41][42][43][44][45][46][47][48][49] It is also possible that if we had accurate estimates of e-liquid nicotine concentration, stronger associations would have been observed with subsequent smoking. Although some studies have reported decreasing levels of nicotine in e-liquids in later-generation e-cigarette devices, the effective dose may have been greater because of the more efficient and powerful latergeneration mod devices available at the time of this study.…”

Atmospheric Pressure Chemical Ionisation study of selected Volatile Organic Compounds (VOCs) by Ion Mobility Spectrometry coupled with orthogonal acceleration Time Of Flight Mass Spectrometry

“…In high purity, it can be used as a viscosity reducer for resins used in photoresist formulations in the electronics industry. Ethyl acetate is rarely selected as a reaction due to its tendency to hydrolysis and transesterification 27,28 . Mixtures containing ethyl acetate are commonly used in column-liquid chromatography and extractions.…”