为考察不同类型烟叶挥发性成分的差异,采用两步顶空进样-GC-MS法分析烤烟、雪茄烟、白肋烟、香料烟和晒黄烟烟叶的挥发性成分.两步顶空进样是将静态顶空进样器与程序升温进样口耦合,采用大体积的顶空进样环提高灵敏度,同时采用程序升温进样口以避免因进样体积较大引起的色谱峰展宽.结果表明:①采用新方法共从5种类型烟叶中检出121种挥发性成分;②采用主成分分析和系统聚类分析验证了挥发性成分组成与烟叶类型的关系;③晒黄烟与香料烟的挥发性成分组成最为相似,雪茄烟挥发性成分组成明显区别于其他类型烟叶;④雪茄烟挥发性成分组成与产地有关.该分析方法简便、灵敏、可靠,可用于烟叶成分研究及品质评价.

为研究吸烟者的唾液成分,改进并优化了闭环回路气提系统,使用咀嚼刺激法以棉球收集吸烟者唾液,建立了吸烟者唾液成分的闭环回路气提-热脱附-气质联用分析方法,采用该方法分析了不同类型卷烟吸烟者的唾液成分.结果表明:①相较于主流烟气,唾液中不同种类化合物的组成以及比例变化明显,其中,变化最为显著的是环戊酮类、吡嗪类和内酯类化合物以及三乙酸甘油酯,唾液中环戊酮类和吡嗪类化合物的色谱峰面积与烟碱的比值提升了10～30倍,内酯类化合物和三乙酸甘油酯的色谱峰面积与烟碱的比值降低了95％以上;②不同类型卷烟吸烟者唾液的主要化合物的色谱峰面积差异明显,差异较大的成分为吡啶类、吡嗪类、环戊烯酮类和呋喃类化合物,英式烤烟型和混合型卷烟吸烟者唾液中吡啶类和吡嗪类化合物的色谱峰面积高于中式烤烟型,中式烤烟型卷烟吸烟者唾液中环戊烯酮类和呋喃类化合物的质量分数则高于英式烤烟和混合型卷烟.

[目的]研究薄板滚筒干燥(KLD)、气流干燥(HDT)两种烘丝模式对烟丝挥发性成分的影响规律.[方法]采用吹扫捕集-多模式进样口-气质联用(P&T-MMI-GC/MS)法鉴定烟丝挥发性成分.[结果](1)主成分分析表明不同烘丝模式对烟丝挥发性成分的影响具有规律性差异.(2)相较烘前,KLD及HDT烘后烟丝中大部分挥发性成分含量降低,明显散失,挥发性成分的散失幅度都与其沸点相关,沸点越低,散失幅度越大;HDT加工烟丝中挥发性成分的散失幅度明显大于KLD.(3)不同类别挥发性成分散失幅度也有差异.脂肪酸降解产物、挥发性有机酸及酚类,烘后散失幅度相对较大;类胡萝卜素降解产物等散失幅度相对较小.

A method for glycosides detection in tobacco leaves by heart cutting Rp/Rp two dimensional liquid chromatography tandem mass spectrometry was established. Three glycosides were determined, including 3-oxo-7,8-dihydro-α-ionol-β-D-glucopyranoside, 3-oxo-α-ionol-β-D-glucopyranoside and 3-hydroxy-β-dihydro-damascone-β-D-glucopyranoside. Only extraction and filtration were required in sample pretreatment. The RSDs of intra day and inter day were in the range of 1.0%~3.2% and 2.8%~8.4%, respectively, which showed good reproducibility. Since sample pretreatment was very simple, the method was quite suitable for daily detection. Different types of tobacco were determined, including Virginian type tobacco, Burley tobacco, oriental tobacco and sun cured tobacco. The results revealed that glycosides in flue cured and fresh Virginian type tobacco were significantly higher than other types, which agreed well with previous reported articles. 157 kinds of Virginian type tobacco samples from different regions were monitored and investigated. Among the factors, which influenced contents of glucosides in Virginian type tobacco, sugar was no longer the major one, catabolite of carotenoids (C13 isoprenol glucosides) and temperature were also considered an important factor in our study.

西柏三烯二醇是重要的中性香味物质——茄酮及其衍生物的前体物,对烟叶的香气风格和品质具有重要影响.建立了以超声波辅助溶剂萃取技术,结合在线液相色谱-气相色谱/质谱(liquid chromatography-gas chromatography/mass spectrometry,LC-GC/MS)联用法对烟草中的西柏三烯二醇进行快速分析的方法.该方法的前处理操作快速简便,检测灵敏度高,重复性好,在对不同地区K326青烟叶中西柏三烯二醇含量的比较分析中也取得了良好的结果,适用于烟草中西柏三烯二醇含量的大规模分析.

In this work, the two-step headspace (HS) technique was applied to determine the actual volatile compositions of tea infusions. In order to eliminate the influence of water vapor to the gas chromatography-mass spectrometry (GC-MS) analysis and enable the capability to determine the volatile compounds in water base samples, a programed temperature vaporizer (PTV) was employed for the additional pre-concentration of thee analytes. While using the reported method, the volatile compounds were retained by the absorbent packed in the PTV, while the water vapor was directly removed through the purge valve. Then the retained volatile compounds were splitlessly injected into the GC column, which means that very low detection limits were achieved with the newly developed method. The obtained results demonstrated that the reported protocol possessed excellent repeatability and stability for volatile compound determination, and a total of 94 volatile compounds were identified from 28 teas. Multivariate data analysis was performed to obtain insights into the relationship between volatile compounds composition of the teas and their types. The volatiles composition of tea was shown to be closely related to the processing techniques adopted. Furthermore, the characteristic volatile compounds of each tea type were also illustrated. All of the results demonstrated that the presented method is a reliable approach to analyze and discriminate various beverages.

[背景和目的]本研究在烟茄嫁接(烤烟品种云烟87为接穗,茄子为砧木)的基础上,检测分析了所获得的超低烟碱含量烟叶TSNAs含量、中性香气物质含量,并对卷制的试验卷烟烟气参数和感官质量进行对比分析.[方法]试验共设烟/烟、烟/茄不培土、烟/茄培土等3个处理.[结果](1)烟茄嫁接的超低烟碱含量烟叶,中性香气物质含量变化较小,但NNN、NNK、NAT和TSNAs含量显著降低,上部叶烟/茄不培土处理的NNN、NNK及TSNAs含量比烟/烟低82.71％、79.46％和68.78％,中部叶烟/茄不培土处理的NNN、NNK及TSNAs含量比烟/烟低79.68％、79.80％和68.63％.(2)卷烟烟气中烟碱含量大幅度降低,其中烟/茄不培土烟叶比常规烟叶低94.12％,焦油、CO、总粒相物、水分和抽吸口数无显著差异.(3)超低烟碱含量烟叶的香气质、浓度、刺激性和燃烧性无显著差异,香气量、杂气和余味与常规烟叶相比有不同程度的降低,劲头下降明显,消费者满足感、愉悦感、接受度显著降低.[结论]通过嫁接技术选择性降低烟碱含量对烟叶化学组成和感官质量产生不同程度的影响.

A novel micro/mesoporous Si/O/C/N quaternary composite aerogels were prepared for the first time and possessed efficient synergistic effect of physisorption and chemisorption. In the preparation process, a simple sol-gel method was applied to integrating nitrogen rich chitosan sol and tetraethoxysilane (TEOS) sol skillfully. The 2 mm-thick Si/O/C/N composite adsorption layer was sandwiched into the acetate filter rod of control sample to form a test sample with high removal efficiency for volatile carbonyl compounds, especially for crotonaldehyde (75.9%) in mainstream cigarette smoke (MCS). The micro/mesopomus Si/O/C/N quaternary composite aerogels have brilliant prospect in the application of cigarette smoke filtration, water purification, etc.

Despite the importance of tobacco (Nicotiana tabacum) in agriculture and model organism investigations, the proteomic changes that occur in the tobacco leaf as it matures remain to be explored. In this study, an isobaric tags for relative and absolute quantification (iTRAQ) strategy was applied to investigate the proteomic profiles of K326 and Honghua Dajinyuan (HD) tobacco leaves at four growth stages. The proteomic profile varied with growth stage in both K326 and HD. Gene ontology (GO) classification was used to identify the biological processes that showed the greatest changes in protein expression between growth stages of HD and K326. Moreover, the number of differentially expressed proteins was greater in HD than in K326, especially during the rosette growth stage and the fast-growing stage. The galactose metabolism and glycosphingolipid biosynthesis-globo series pathways appeared only during the rosette growth stage of HD. It therefore appears that these pathways may be correlated with tobacco mosaic disease. The identification of these pathways should prove useful in investigations of the pathogenesis of tobacco mosaic virus.

A heart-cutting two dimensional liquid chromatography coupled with tandem mass spectrometry method was developed for the analysis of tobacco-specific N-nitrosamines (TSNAs) at low concentration level in Virginia-type cigarette smoke. A strong cation exchange column was utilized for the first dimensional separation, which effectively removed acidic and neutral components in the smoke, followed by a reversed phase liquid chromatography coupled with tandem mass spectrometric analysis. To capture components of the TSNAs in the effluent on the trapping column, a compensating pump was applied for online dilution and pH adjustment during the period of the TSNAs fraction transferring and enrichment. Highly sensitive determination of the TSNAs in mainstream cigarette smoke was achieved by isotope deuterated internal standards under the multiple reaction monitoring mode. Compared with traditional methodologies, the method was almost no matrix interference. Limits of quantity for the TSNAs were within 0.027-0.094 ng/mL, and the results showed good reproducibility and accuracy. Finally, the new method was applied for analysis of the Kentucky reference cigarettes and the results agreed well with joint experiments of Cooperation Centre for Scientific Research Relative to Tobacco.

In order to quantify the nicotine and cotinine levels in human urine, an automatic online thermal desorption-gas chromatography/mass spectrometry (GC/MS) method was developed. By using steam-treated SBA-15 type mesoporous silica as the sorbent and coupling with GC/MS, a device was designed for the efficient enrichment and rapid online analysis of nicotine and its metabolite cotinine in urine. The results showed that the device realized the online sample adsorption, thermal desorption, injection and analysis. The SBA-15 type mesoporous silica modified with steam at 700 ℃ for 6 h significantly improved the thermal desorption of nicotine and cotinine. Calibration curves in the range of 1-2 000 ng/mL of the analytes were established with R2 higher than 0.999 5. The spiked recoveries of the analytes ranged from 97.28% to 104.55% with the relative standard deviations(RSDs)of 0.25%-3.18%. The limits of detections for nicotine and cotinine were 0.5 and 0.4 ng/mL, respectively. This method is highly automatic, rapid and suitable for the analysis of nicotine and cotinine in human urine samples.

This paper proposed a newly developed heart-cutting two-dimensional supercritical fluid chromatography-high-performance liquid chromatography system coupled to tandem mass spectrometry (SFC-HPLC-MS/MS) for the determination of four tobacco-specific nitrosamines (TSNAs) in cigarette mainstream smoke. The orthogonality of five SFC columns and two HPLC columns was evaluated. The 1-AA column was applied for the first dimensional (1D) SFC separation to isolate the target compounds from the complex cigarette smoke matrices, and a trapping column in conjunction with an isocratic pump was employed to capture the 1D elutes. Then, the trapped 1D elutes were transferred into the C18 column through a two-position/six-port valve for the second dimensional (2D) analysis. The ion suppression was significantly reduced by the established SFC-HPLC system; meanwhile, the matrix interferences were eliminated as the results demonstrated. A dynamic range between 0.1 and 20 ng/mL was achieved with LOQs of 0.72 μg/cig for N-nitrosonornicotine (NNN), 0.66 μg/cig for nicotine-derived nitrosamine ketone (NNK), 0.81 μg/cig for N-nitrosoanatabine (NAT), and 0.39 μg/cig for N-nitrosoanabasine (NAB). All the results revealed that the presented method exhibited good repeatabilities and recoveries and could be used as a rapid and reliable approach for routine analysis of TSNAs in mainstream smoke.

在叶丝样品中掺配了5种不同比例的梗丝卷制成了卷烟样品,然后通过中心切割气质联用技术对卷烟样品主流烟气的粒相物中香味成分进行测定分析.分析结果表明:随着梗丝掺配比例的增加,样品卷烟的单支克重、抽吸口数、总粒相物含量和主流烟气粒相物中香味成分含量均逐渐减少.此外,粒相物中大部分香味成分的含量也都逐渐降低.而由于梗丝中木质素、纤维素、果胶等大分子含量高以及燃烧性好,使得叶丝中梗丝量掺配增加后,烟气中2-甲基吡嗪等美拉德反应产物、香兰素等木质素热解产物以及2,3-二甲基-2-环戊烯-1-酮等大分子热解产物含量也随之增加.这些研究结果表明梗丝掺配虽然可以有效实现降焦,但仍需要通过加香方式来弥补梗丝加入后香气不足的问题.

Nicotine (Nic) exposed to the environment which comes from tobacco products is the main addictive agent and specific classes of hazardous compound that merit concern. In this study, we have established a fast and reliable method to achieve specific detection of Nic in natural nicotiana tabacum within 30 s through a miniaturized platform based on screen printed gold electrode (SPE). A simple electrochemical pretreatment mean was employed on gold surface that led to the exposure of Au (111) facet and a convenient sample pretreatment method was adopted to realize the extraction of Nic in tobacco. The present electrochemical sensor exhibits an ample range of sensing from 10 μg/g to 200 μg/g, which is able to compliance with tobacco industry testing standards of actual samples. Over 60 sampling points from different origins in China or other countries were performed with direct analysis using this method and satisfactory results have been obtained. The proposed approach was demonstrated to be a very promising platform for significantly improving analytical efficiency in laboratories as well as for monitoring the source reduction control of Nic in the environment.

In this work, a strategy of in-series combination of ultrasound-assisted extraction and online LC-GC/MS was constructed for effective separation and analysis of sucrose esters in tobacco. Sucrose esters were first extracted by ultrasoundassisted extraction with high efficiency and easyhandling. Online LC-GC/MS was then applied for sucrose ester clean-up and analysis. To better evaluate the effectiveness of this strategy, we limited our focus to five groups of sucrose ester isomers. Each group differed in mass from the next by 14 Da. The obtained coefficient of the calibration curve was 0.9986. Limit of detection (LOD) and limit of quantitation (LOQ) were 0.05 and 0.16 μg/ mL, respectively. The recovery was above 90% and the reproducibility was below 4%. This strategy was subsequently applied to the comparison of relative amounts of five groups of sucrose esters extracted from three different parts of aromatic tobacco. The satisfactory performance indicated that this strategy has great prospect for the rapid and high-throughput analysis of sucrose esters in tobacco.

Two metal-organic frameworks [(Zn0.5L)·(H2O)]n (1) and [(Ni0.5L)·(H2O)]n (2) constructed by the 3-formyl-4-(pyridin-4-yl) benzoic acid ligand (HL) were synthesized and characterized by single-crystal X-ray diffraction. 1 crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) Å, V = 3243.2(3) Å3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I > 2σ(I). 2 is isostructural to 1, which also crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) Å, V = 3243.2(3) Å3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I > 2σ(I). Additionally, thermogravimetric analysis, FT-IR spectroscopy and powder X-ray diffraction were discussed.

为了进一步明确不同类型烟叶样品长期贮藏过程中主要酮类香气成分变化规律,采用LC-GC方法测定调制后样品在6年自然贮藏过程中主要酮类香气成分含量.结果表明:1)随贮藏时间增加,烟叶主要酮类香气成分变化均符合二次曲线模型,白肋烟酮类香气物质总量最高,贮藏期间所有阶段平均值为46.25 1μg/g,且在长期贮藏过程中含量增加时间长,酮类挥发性香气含量峰值出现在61个月.其次为晒烟,贮藏期间平均含量为40.053μg/g,酮类挥发性香气含量峰值出现在48个月.烤烟贮藏期间平均含量最低,为26.306μg/g,酮类挥发性香气含量峰值出现在38个月.2)类胡萝卜素降解产物巨豆三烯酮、氧化紫罗兰酮等含量先上升后下降,呈现抛物线形式.茄酮、降茄二酮等含量逐渐下降.3)白肋烟巨豆三烯酮等含量最高;晒烟β-紫罗兰酮(0.830μg/g)等含量最高;烤烟降茄二酮等含量较高,两地区烤烟降茄二酮平均含量达到0.400μg/g.不同类型烟叶样品适宜的陈化期不同,白肋烟和晒烟比烤烟更耐贮藏,烤烟贮藏时间应控制在35个月内,白肋烟晒烟贮藏时间不超过60个月,有利于提高烟叶可用性.

A novel phosphonate-based chiral metal-organic framework 1 was synthesized from C-2-symmetric 1,1'-biphenol-based ligand and structurally characterized by single-crystal and powder X-ray diffraction, Fourier-transform infrared spectra (FTIR), circular dichroism (CD) and thermogravimetric analyses (TGA). Two neighboring Mn ions are linked by two carboxylate groups and one phosphate group to form a di-manganese unit [Mn-2] and each [Mn-2] cluster in 1 is linked by five ligands, generating a 3D network with fns topology. In addition, the photoluminescence properties of 1 and H4L were investigated.