Solid phase microextraction of alkenylbenzenes and other flavor-related compounds from tobacco for analysis by selected ion monitoring gas chromatography-mass spectrometry

Uncovering cloves: characterization of volatile compounds present in clove cigarettes

Indonesian clove cigarettes-called "kretek" due to the crackling sound that can be heard when the product burns-are tobacco products containing clove and the "saus", a mixture of essential oils and plant extracts whose ingredients are mostly kept in secret. It is important to determine which ingredients those are to properly assess the effects that clove cigarettes can cause. An organoleptic, qualitative and quantitative analysis was made in 9 different brands of clove cigarettes obtained in Brazil. Nicotine, eugenol, menthol, and β-caryophyllene were quantified through gas chromatography coupled to mass spectrometry. The samples presented 20 different compounds, and all samples had a different combination of the compounds. Nicotine concentrations were generally higher than eugenol, and lower than nicotine concentration in a conventional cigarette. One sample had menthol even though the cigarette pack did not inform that it was a menthol product. There were traces of 2 unusual substances. Clindamycin is an antibiotic that can be used to treat bacterial infections in respiratory airways, and octodrine is an amphetaminic stimulant used in nutritional supplements, considered as a substance of doping by the World Anti-Doping Association. The presence of both substances was not tested using certified reference materials, but its possible presence raises concern about the compounds in kretek cigarettes. There should be more studies about the contents of clove cigarettes, to improve antitobacco legislations and regulations. This way it would be possible to properly inform the risks of smoking clove cigarettes and to diminish the number of tobacco users throughout the world.

Where should I start? A scoping review about the publications on clove cigarettes

INTRODUCTION

The general lack of knowledge about the composition of clove cigarettes and the large number of terms that can be used to define different types of cigarettes that contain cloves makes it difficult to find scientific articles focused on the subject. We reviewed the publications that cited clove cigarettes to assess their relevance.

METHODS

We searched publications on Scopus, ScienceDirect, PubMed, and Portal CAPES during the first semester of 2021, without date restrictions. Through a quality assessment, the studies found were assorted in ten different categories.

RESULTS

Indonesian clove cigarettes-also known as kretek-are a mixture of tobacco and cloves rolled in a cigarette and sprayed with oils, plant extract, and food flavorings, in an unknown quantity and composition, different from each brand, which is usually kept in secret. Due to the relatively low prevalence of use in the general population, most publications on tobacco products tend to ignore clove cigarettes or place them in an existing category. Clove cigarettes can be hand-rolled, machine-made, filtered, unfiltered, and each form can be named differently. The interchangeable use of each term, sometimes grouping conventional cigarettes in the mix, can lead the researcher to consider a publication that should be excluded.

CONCLUSION

The existing regulations on flavored cigarettes, although well-intentioned, are still somewhat vague and broad, leaving possible loopholes that can be exploited by the tobacco industries. Fully understanding the precise effects caused by clove cigarettes can be an important tool in future discussions about tobacco control.

Flavor components in tobacco capsules identified through non-targeted quantitative analysis

Tobacco flavors increase the attractiveness of a tobacco brand and ultimately promote addiction. Information about what flavor and how much flavor is in flavor capsules can provide an effective way to regulate tobacco flavor. In this study, 128 flavor chemicals were identified and quantified by gas chromatography-mass spectrometry using libraries and authentic standards. Validation of the developed method was performed for interference, detection limits, calibration curves, accuracy, and precision. Menthol was the main ingredient in all capsules, and the carcinogenic pulegone was detected. Detected menthofuran, benzyl alcohol, geraniol, and eugenol cause toxic or severe irritation, and detected lactones can increase nicotine addiction by inhibiting nicotine metabolism in smokers. Margin of exposures for carcinogenic pulegone and non-carcinogenic menthol were well below safety thresholds, indicating a significant risk of inhalation exposure. It is desirable to prohibit the use of flavor capsules in consideration of human risk.

Qualitative and quantitative comparison of flavor chemicals in tobacco heating products, traditional tobacco products and flavoring capsules

A gas chromatography-mass spectrometric (GC-MS) method was developed for the qualitative and quantitative analysis of flavor chemicals in tobacco heating products (THPs), traditional tobacco products (TTPs) and their flavoring capsules. A total of 283 compounds were identified through non-target analysis, and the final 302 compounds were selected to develop an analytical method. The lower limits of detection (LOD) of analytes were 0.00074-12 mg/kg and their LOD range was wide depending on the presence or absence in the reference cigarette. The precision of the 302 compounds was less than 24.5%, and the accuracy ranged from 80.0% to 120%. A total of 190 flavors and 5 contaminants were determined in 21 THP, 10 TTP, 8 THP capsules and 11 TTP capsules. When comparing the total flavor content of flavors per cigarette, it was in the order of THP capsule> TTP capsule ≫ THP ≫ TTP. The correlations between the 53 cigarette products and 190 flavor chemicals were analyzed using PCA. It has been demonstrated that PCA results can be a useful tool in differentiating brands and manufacturers of tobacco products.

Profiling of volatile substances by direct thermal desorption gas chromatography high-resolution mass spectrometry for flagging a characterising flavour in cigarette tobacco

This paper describes an analytical method that supports the implementation of articles 9 and 10 of the WHO Framework Convention on Tobacco Control (FCTC) regarding the provisions on the reduction of the palatability and attractiveness of tobacco products regarding flavour ingredients. This study aimed to develop a screening method to identify cigarettes that may have a characterising flavour to support the implementation of the ban of characterising flavours of tobacco products, as laid down in the US and EU law. An analytical method combining direct thermal desorption and GC-QTOF MS was developed for acquiring the profile of volatile and semi-volatile substances in tobacco. A database of flavour additives was created comprising 133 compounds. A group of cigarettes without a declared characterising flavour was used to establish a reference profile of flavouring chemicals commonly present in tobacco products. A reference profile was modelled both by the means of principal component analysis (PCA) and based on the calculation of threshold values specified as 95th percentile of measured compounds' relative responses. Cigarettes and roll-your-own tobacco labelled as flavoured were analysed to evaluate the discrimination power of the method. A constructed model of the reference cigarettes allowed the differentiation of the flavoured tobacco products from the reference group. The method allows drawing conclusions on the chemical profiles of flavour constituents of tobacco products at even sensorial subliminal concentration levels and is suitable for both the initial screening of products on the market for characterising flavours and for confirmatory purposes after sensory analysis.

Risk Analysis for the Carcinogen Pulegone in Mint- and Menthol-Flavored e-Cigarettes and Smokeless Tobacco Products

This analysis assesses the levels of the carcinogen pulegone in top-marketed brands of e-cigarettes and smokeless tobacco products.

Analysis of coumarin and angelica lactones in smokeless tobacco products

Differences in health risks between different styles of smokeless tobacco products (STPs) have prompted interest in their relative levels of toxic chemicals. We report here the development of methods for the analysis of STPs for coumarin and for α-angelica lactone (α-AL), both of which have been included in various published lists of tobacco toxicants. We have also determined the concentrations of these lactones in commercial STPs from the US and Sweden, representing 80-90% of the 2010 market share for all the major STP categories in these two countries: 65 products (plus two reference products) for coumarin and 66 commercial products for α-AL. For coumarin, methanol extracts of the STPs were analysed by HPLC/MS/MS. The lower limit of quantification (LOQ) and limit of detection (LOD) were, respectively, 100 and 30 ng coumarin/g of STP on a wet weight basis (WWB). Alpha-AL was determined via direct headspace GC/MS. The LOQ and LOD were 65 and 30 ng/g WWB respectively. Coumarin was detected In 3/33 Swedish snus, 5/13 US chewing tobaccos, 16/16 moist snuffs and 5/6 dry snuffs. Concentrations in those samples with quantifiable coumarin contents ranged from 186 to 1656 ng/g WWB. Concentrations of coumarin measured in this study were consistent with levels naturally found in tobacco. None of the STPs analysed would significantly contribute to coumarin exposure in consumers compared with dietary sources, and estimated exposure levels were 1000× lower than the European Food Safety Authority Tolerable Daily Intake. Hence the relevance of coumarin to the toxicity of STPs and its inclusion in the FDA's list of harmful and potentially harmful compounds list is questionable. Measurements of α-AL in these STPs found that the majority did not have quantifiable contents, however, for three STPs concentrations of α-AL were above the LOQ (116-140 ng/g WWB) and for four other STPs concentrations of α-AL could be estimated between the LOD and LOQ. Beta-angelica lactone was tentatively identified in three of the STPs but the levels could not be reliably quantified. The levels of α-AL in tobacco products are reported here for the first time, but the relevance of α-AL to the toxicity of STPs is also highly questionable given that it has GRAS status as a permitted food additive.

Quantitative analysis of menthol and identification of other flavoring ingredients in capsule cigarettes marketed in Korea

Currently, capsule cigarettes have been introduced by tobacco industries and their sales have increased exponentially. However, the capsule flavoring ingredients and their safety are still unknown. Although the contents of menthol and other ingredients directly added to cigarettes have been determined extensively, no analogous study exists for menthol-containing cigarette capsules. Basic physical properties of capsules in all 31 different capsule cigarettes commercially available in Korea were investigated, and their menthol contents were determined in this study. Other ingredients in these capsules were also qualitatively analyzed; methyl octanoate, menthone and isopulegol as well as menthol were detected in all the capsules. There is considerable variability in basic physical properties and menthol contents of cigarette capsules depending on their brand styles. The menthol contents of capsules and whole cigarettes are similar or higher than those previously reported for conventional menthol cigarettes. This is the first report on the physical properties of capsules and the fact that a wide range of menthol contents in capsule cigarettes, regardless of flavor types, allows smokers to select menthol content to their liking.

Simultaneous Determination of Coumarin and Its Derivatives in Tobacco Products by Liquid Chromatography-Tandem Mass Spectrometry

In this paper an analytical method based on high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) for the determination of coumarin and its derivatives in tobacco products was developed. The MS/MS fragmentation pathways of the eight coumarins were elucidated. The new analytical method was defined based on two main axes, an extraction procedure with acetonitrile and analyte detection performed by HPLC-MS/MS in electron impact mode. The excellent selectivity and sensitivity achieved in multiple reaction monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the coumarin flavor additives. Under the optimized gradient elution conditions, it took only 4.5 min to separate all eight coumarins. Good linearity for all the analytes were confirmed by the correlation coefficient r², ranging from 0.9987 to 0.9996. The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range of 0.5-1.7 μg/kg and 1.7-5.2 μg/kg, respectively. The average recoveries at three spiked levels (LOQ, 1.5LOQ, 2LOQ) were all in the range of 69.6%-95.1% with RSDs (n = 6) lower than 5.3%. The method of HPLC-MS/MS developed in this study was initially applied to the research of coumarin flavor additives in tobacco products collected from the located market in Beijing from China and proved to be accurate, sensitive, convenient and practical.

Multivariate analysis of mainstream tobacco smoke particulate phase by headspace solid-phase micro extraction coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

A method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography (GC×GC) coupled to time-of-flight mass spectrometry (TOFMS) was developed and applied to evaluate profiles of volatile compounds present in mainstream tobacco smoke particulate matter trapped on glass fiber filters. Six SPME fibers were tested for the extraction capacities toward selected compounds, showing the best results for the polyacrylate fiber. The optimization of the extraction conditions was carried out using multivariate response surface methodology. Two cigarette types differing in a filter design were analyzed using optimized conditions. A template was built in order to generate comprehensive chemical information, which conceded obtaining consistent information across 24 chromatograms. Principal component analysis (PCA) allowed a clear differentiation of the studied cigarette types. Fisher ratio analysis allowed identification of compounds responsible for the chemical differences between the cigarette samples. Of the selected 143 most important ones, 134 analytes were reduced by the active carbon filter, while for nine, classical cellulose acetate filter was more efficient.

Quantitation of Ten Flavor Compounds in Unburned Tobacco Products

Most research on unburned tobacco has focused on the harmful chemicals associated with the tobacco itself. However, certain flavor additives in tobacco products can pose additional health risks. Flavors like camphor, coumarin, pulegone, eugenol, methyl salicylate, menthol and diphenyl ether have exhibited biological activity and/or toxicity in both lab animals and humans. This publication presents a new GC/MS method for the quantitation of ten flavor compounds (eucalyptol, camphor, menthol, pulegone, ethyl salicylate, methyl salicylate, cinnamaldehyde, eugenol, diphenyl ether and coumarin) in a variety of tobacco products, including smokeless products and cigar filler. Excellent linearity (>0.997), accuracy (93.9% - 106.6%) and precision (C.V., 0.5% - 3.0%) were achieved for all flavor analytes measured. A summary of the concentrations of these flavors in selected international smokeless tobacco (SLT) products including zarda, quiwam, gutkha, and khaini varieties from Southeast Asia and snuff, clove cigarette filler and flavored cigar filler from the United States is reported. High concentrations of eugenol (2110 μg/g), coumarin (439 μg/g), camphor (1060 μg/g) and diphenyl ether (4840 μg/g) were found in selected products. Accurate identification and quantitation of potentially hazardous flavor compounds is important because they can exist in relatively high levels in some tobacco products, including international SLT products. We outline a versatile method which can be used to quantitate flavor compounds in multiple types of tobacco products.

Waterpipe smoking: analysis of the aroma profile of flavored waterpipe tobaccos

In the last years the habit of smoking waterpipes has spread worldwide, especially among young people and emerged as global health issue. Although research is now under way for no less than 40 years in the field of waterpipe smoking, in comparison to cigarette smoking there is still insufficient knowledge on the real composition and the toxicity of the smoke inhaled and the resulting levels of exposure against particular hazardous ingredients. In most cases for waterpipe smoking a highly flavored tobacco called "moassel" is used. However, the number, quantity and toxicity of the added flavorings are widely unknown. In this study the static headspace gas chromatography-mass spectrometry (SHS-GC-MS) was used to identify 79 volatile flavor compounds present in waterpipe tobacco. Among these eleven compounds were analyzed quantitatively. The results show that waterpipe tobacco contains high amounts of the fragrance benzyl alcohol as well as considerable levels of limonene, linalool and eugenol, all of which are known as being allergenic in human skin. The proposed SHS-GC-MS method has been validated and found to be accurate, simple and characterized by low limits of detection (LOD) in the range of 0.016 to 4.3 µg/g tobacco for benzaldehyde and benzyl alcohol, respectively. The identification and characterization of waterpipe tobacco ingredients indeed reveals crucial for the assessment of potential health risks that may be posed by these additives in smokers.

Simultaneous determination of 23 flavor additives in tobacco products using gas chromatography-triple quadrupole mass spectrometry

A method based on gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ MS/MS) was developed for the determination of 23 widely used flavor additives in tobacco products in this paper. The MS/MS fragmentation pathway of the cinnamic esters additives was illustrated. The new analytical method was defined based on two main axes, ultrasonic solvent extraction procedure with dichloromethane and analyte detection performed by GC-QqQ MS/MS in electron impact mode. The excellent selectivity and sensitivity achieved in multiple reactions monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the tobacco flavor additives. The linear range of the 23 flavor additives is 0.2-500.0μg/L with good correlation coefficients (r(2)>0.9963). The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range 0.1-2.0μg/L and 0.4-6.0μg/kg, respectively. The average recoveries at three spiked levels (LOQ, 2LOQ, 4LOQ) were all in the range 62.1-93.8% with RSDs (n=6) lower than 7.8%. The method of GC-QqQ MS/MS developed in this study was initially applied to the research of flavor additives in 12 retail cigarette samples and proved to be accurate, sensitive, convenient and practical.

Determination of myristicin in commonly spices applying SPE/GC

The increasing use of myristicin (a component of nutmeg) as a cheap hallucinogenic intoxicant requires from the world of science the elaboration of new methods for determination of this compound in daily-use foodstuffs. The present study describes a fast, simple and sensitive method of myristicin analysis in nutmeg and spices containing it using gas chromatography combined with ultrasonic solvent extraction and solid phase extraction processes. The developed method is characterized by high recovery (almost 100%), a low detection limit 1.35 ng g(-1) and good repeatability (average RDS value equal 2.39%). The presented analytical approach constitutes a substantial improvement on previously reported methods for myristicin analysis and seems to be the method of choice for determining the amount of the compound in spices containing nutmeg.

Resolving batch chromatographic overlapping peaks of flavoring essence using stepwise key spectrum selection

Stepwise key spectrum selection (SKSS) was introduced to resolve batch overlapping peaks from gas chromatography-mass spectrometry (GC-MS) analysis of ten batch tobacco flavoring samples in different storage times. Resolution was implemented on a software platform that embedded the SKSS method. The data from GC-MS analysis of the samples were saved and prepared in ASCII files and then were inputted into the software platform for visual inspections. The data segment with overlapping peaks was precut for subsequent analysis. Spectral background in the data was removed using a linear fitting of the baseline. Four components in the overlapping peaks were automatically detected by the SKSS method. The resolution of the concentration profiles and spectra of the four components was conducted by setting only one parameter, the negative area ratio, as 0.01. The fixed size moving window evolving factor analysis and evolving factor analysis were applied to validate the resolved concentration profiles. The resolved mass spectra were validated by the searched standard through library search at the pure component regions revealed by the resolved concentration profiles. The results showed that the SKSS method could be a simple but powerful tool in resolving batch chromatographic overlapping peaks.

An improved headspace solid-phase microextraction method for the analysis of free-base nicotine in particulate phase of mainstream cigarette smoke

The content of free-base nicotine in cigarette smoke is a controversial subject, partly due to methodological issues. In this investigation, an improved method to measure free-base nicotine in cigarette smoke using headspace solid-phase microextraction (HS-SPME) combined with GC/MS analysis, was developed and validated for this purpose. Cigarette smoke particulate phase (PP) was collected onto a 44mm glass fiber filter pad. The pad was cut in halves with one half used to determine the concentrations of total nicotine and water. The remaining half was analyzed by HS-SPME for free-base nicotine. The following factors were found to have a significant impact on the responses of free-base nicotine: SPME fiber type, pre-equilibrium time before HS-SPME, extraction time and temperature, PP water content, and the solvent used for the preparation of standards. It was also found that the impact of PP water content on the determination of free-base nicotine from smoke sample could be corrected by a water correction factor calculated based on an experimentally determined reciprocal model. The precision of the method was evaluated with smoke samples of reference cigarettes: Canadian flue-cured monitor and Kentucky reference 2R4F. The RSD values obtained were in the 12.8-16.8% range.

Pattern recognition and genetic algorithms for discrimination of orange juices and reduction of significant components from headspace solid-phase microextraction

INTRODUCTION

Orange (Citrus sinensis L.) juice comprises a complex mixture of volatile components that are difficult to identify and quantify. Classification and discrimination of the varieties on the basis of the volatile composition could help to guarantee the quality of a juice and to detect possible adulteration of the product.

OBJECTIVE

To provide information on the amounts of volatile constituents in fresh-squeezed juices from four orange cultivars and to establish suitable discrimination rules to differentiate orange juices using new chemometric approaches.

METHODOLOGY

Fresh juices of four orange cultivars were analysed by headspace solid-phase microextraction (HS-SPME) coupled with GC-MS. Principal component analysis, linear discriminant analysis and heuristic methods, such as neural networks, allowed clustering of the data from HS-SPME analysis while genetic algorithms addressed the problem of data reduction. To check the quality of the results the chemometric techniques were also evaluated on a sample.

RESULTS

Thirty volatile compounds were identified by HS-SPME and GC-MS analyses and their relative amounts calculated. Differences in composition of orange juice volatile components were observed. The chosen orange cultivars could be discriminated using neural networks, genetic relocation algorithms and linear discriminant analysis. Genetic algorithms applied to the data were also able to detect the most significant compounds.

CONCLUSIONS

SPME is a useful technique to investigate orange juice volatile composition and a flexible chemometric approach is able to correctly separate the juices.

Determination of eugenol, anethole, and coumarin in the mainstream cigarette smoke of Indonesian clove cigarettes

Indonesian clove cigarettes (kreteks), typically have the appearance of a conventional domestic cigarette. The unique aspects of kreteks are that in addition to tobacco they contain dried clove buds (15-40%, by wt.), and are flavored with a proprietary "sauce". Whereas the clove buds contribute to generating high levels of eugenol in the smoke, the "sauce" may also contribute other potentially harmful constituents in addition to those associated with tobacco use. We measured levels of eugenol, trans-anethole (anethole), and coumarin in smoke from 33 brands of clove-flavored cigarettes (filtered and unfiltered) from five kretek manufacturers. In order to provide information for evaluating the delivery of these compounds under standard smoking conditions, a quantification method was developed for their measurement in mainstream cigarette smoke. The method allowed collection of mainstream cigarette smoke particulate matter on a Cambridge filter pad, extraction with methanol, sampling by automated headspace solid-phase microextraction, and subsequent analysis using gas chromatography/mass spectrometry. The presence of these compounds was confirmed in the smoke of kreteks using mass spectral library matching, high-resolution mass spectrometry (+/-0.0002 amu), and agreement with a relative retention time index, and native standards. We found that when kreteks were smoked according to standardized machine smoke parameters as specified by the International Standards Organization, all 33 clove brands contained levels of eugenol ranging from 2,490 to 37,900 microg/cigarette (microg/cig). Anethole was detected in smoke from 13 brands at levels of 22.8-1,030 microg/cig, and coumarin was detected in 19 brands at levels ranging from 9.2 to 215 microg/cig. These detected levels are significantly higher than the levels found in commercial cigarette brands available in the United States.

Determination of coumarin, vanillin, and ethyl vanillin in vanilla extract products: liquid chromatography mass spectrometry method development and validation studies

A LC-MS method was developed for the determination of coumarin, vanillin, and ethyl vanillin in vanilla products. Samples were analyzed using LC-electrospray ionization (ESI)-MS in the positive ionization mode. Limits of detection for the method ranged from 0.051 to 0.073 microg mL(-1). Using the optimized method, 24 vanilla products were analyzed. All samples tested negative for coumarin. Concentrations ranged from 0.38 to 8.59 mg mL(-1) (x =3.73) for vanillin and 0.33 to 2.27 mg mL(-1) (x =1.03) for ethyl vanillin. The measured concentrations are compared to values calculated using UV monitoring and to results reported in a similar survey in 1988. Analytical results, method precision, and accuracy data are presented.

Quantification of flavor-related compounds in the unburned contents of bidi and clove cigarettes

Bidi cigarettes, small hand-rolled cigarettes produced primarily in India, are sold in the United States in a wide variety of candy-like flavors (e.g. dewberry, chocolate, clove) and are popular with adolescents. Many flavored bidis contain high concentrations of compounds such as eugenol, anethole, methyleugenol, pulegone, and estragole; several of these compounds have known toxic or carcinogenic properties. Clove cigarettes, or kreteks, are another highly flavored tobacco product with high levels of eugenol due to clove buds present in the tobacco filler. In this study, compounds in the burnable portion-the filler and wrapper material actually consumed during the smoking of bidis, kreteks, and U.S. cigarettes-were analyzed. Flavor-related compounds were solvent extracted from the burnable portion of each cigarette with methanol. An aliquot of the methanol extract was heated, and the sample headspace was sampled with a solid-phase microextraction fiber and introduced into a gas chromatograph-mass spectrometer for analysis in selected-ion monitoring mode. High levels of eugenol were detected in five clove-flavored bidi brands ranging from 78.6 to 7130 microg/cigarette (microg/cig), whereas diphenyl ether (128-3550 microg/cig) and methyl anthranilate (154-2360 microg/cig) were found in one grape-flavored bidi brand. A nontobacco herbal bidi brand contained the greatest variety of compounds, including anethole (489-665 microg/cig), eugenol (1670-2470 microg/cig), methyleugenol (27.7-36.6 microg/cig), safrole (32.4-34.4 microg/cig), myristicin (170-247 microg/cig), and elemicin (101-109 microg/cig). Filler from kreteks was found to contain high levels of eugenol, anethole, and coumarin. Flavored bidis and clove cigarettes contain a number of compounds that are present at levels far exceeding those reported in U.S. cigarette tobacco. Research is underway to determine the levels of these compounds delivered in smoke. It is not known what effect inhalation of these compounds has on smokers.

Application of headspace solid phase microextraction to qualitative and quantitative analysis of tobacco additives in cigarettes

Cigarettes may contain up to 10% by weight additives which are intended to make them more attractive. A fast and rugged method for a cigarette-screening for additives with medium volatility was developed using automatic headspace solid phase microextraction (HS-SPME) with a 65 microm carbowax-divinylbenzene fiber and gas chromatography-mass spectrometry (GC-MS) with standard electron impact ionisation. In three runs, each cigarette sample was extracted in closed headspace vials using basic, acidic and neutral medium containing 0.5 g NaCl or Na2SO4. Furthermore, the method was optimized for quantitative determination of 17 frequently occurring additives. The practical applicability of the method was demonstrated for cigarettes from 32 brands.

Concentrations of nine alkenylbenzenes, coumarin, piperonal and pulegone in Indian bidi cigarette tobacco

Indian-made bidi cigarettes sold in the United States are available in a variety of exotic (e.g. clove, mango) and candy-like (e.g. chocolate, raspberry) flavors. Because certain tobacco flavorings contain alkenylbenzenes and other toxic or carcinogenic chemicals, we measured the concentration of flavor-related compounds in bidi tobacco using a previously developed method. Twenty-three brands of bidis were sampled using automated headspace solid-phase microextraction and subsequently analyzed for 12 compounds by gas chromatography-mass spectrometry. Two alkenylbenzene compounds, trans-anethole and eugenol, were found in greater than 90% of the brands analyzed. Methyleugenol, pulegone and estragole were each detected in 30% or more of the brands, whereas safrole and elemicin were not detected in any of the brands. The flavor-related compounds with the highest tobacco concentrations were eugenol (12,000 microg/g tobacco) and trans-anethole (2200 microg/g tobacco). The highest eugenol and trans-anethole concentrations found in bidi tobacco were about 70,000 and 7500 times greater, respectively, than the highest levels previously found in US cigarette brands. Measurement of these compounds is crucial to evaluation of potential risks associated with inhaling highly concentrated flavor-related compounds from bidis or other tobacco products.

Assessment of strawberry aroma through SPME/GC and ANN methods. Classification and discrimination of varieties

To provide an efficient and running analytical tool to strawberry plant breeders who have to characterize and compare the aromatic properties of new cultivars to those already known, a HS-SPME/GC-MS analysis method has been coupled with a statistical treatment method issued from the current development of artificial neuron networks (ANN), and more specifically, the unsupervised learning systems called Kohonen self-organizing maps (SOMs). So, 70 strawberry samples harvested at CIREF from 17 known varieties have been extracted by using a DVB/Carboxen/PDMS SPME fiber according to the headspace procedure, and then chromatographed. A panel of 23 characteristic aromatic constituents has been selected according to published results relative to strawberry aroma. The complex resulting matrix, collecting the relative abundance of the 23 selected constituents for each sample, has been input into the SOM software adapted and optimized from the Kohonen approach described by one of the authors. After a period of training, the self-organized system affords a map of virtual strawberries to which real samples are compared and plotted in the best matching unit (BMU) of the map. The efficiency for discriminating the real samples according to their variety is dependent on the number of units selected to define the map. In this case, a 24-unit map allowed the complete discrimination of the 17 selected varieties. Moreover, to test the validity of this approach, two additional samples were blind-analyzed and the results were computed according to the same procedure. At the end of this treatment, both samples were plotted into the same unit as those of the same variety used for training the map.

Solid-phase trapping of solutes for further chromatographic or electrophoretic analysis

Because of its simplicity, speed and effectiveness, solid-phase extraction (SPE) has become the preferred technique for concentration of selected analytes prior to chromatographic or electrophoretic analysis. In this review the historical development of SPE is briefly traced. Then the principles of SPE are reviewed in some detail. Numerous references are given on the format, sorbents, elution conditions, online techniques and automation with special emphasis on relatively recent developments. The principles and recent advances in solid-phase microextraction (SPME) are also reviewed. The final section on selected recent applications includes an extensive list of references to work published within the last three years. Future trends and developments are discussed briefly.

Quantitation of flavor-related alkenylbenzenes in tobacco smoke particulate by selected ion monitoring gas chromatography-mass spectrometry

Little is known about the possible health effects associated with inhaling alkenylbenzenes through cigarette smoking, even though these flavor-related compounds have known toxic effects in animals. We developed a rapid and sensitive solid-phase extraction (SPE) method to quantify seven alkenylbenzenes and piperonal in mainstream cigarette smoke particulate. The smoke particulate fraction of a single cigarette was collected on Cambridge filter pads, solvent extracted, concentrated, purified with SPE, and analyzed by selected ion monitoring gas chromatography-mass spectrometry. We positively identified and quantified five alkenylbenzenes compounds (eugenol, isoeugenol, methyleugenol myristicin, and elemicin) and piperonal in the smoke particulate from eight U.S. brands with mean levels (measured in triplicate) ranging from 6.6 to 4210 ng per cigarette. Additionally, complete blocking of nearly invisible ventilation holes in the cigarette filter increased 2- to 7-fold the percent transfer of alkenylbenzenes from tobacco to the particulate fraction of mainstream smoke.