建立了金捕集-电感耦合等离子体质谱法同时测定电子烟气溶胶中铬、镍、砷、铅、镉、锑、汞7种重金属元素的方法.实验优化了电子烟气溶胶的捕集条件,采用含2.0 mg/L金元素的5.0％(体积比)硝酸溶液捕集吸收气溶胶,捕集阱为2瓶串联,每个捕集阱含吸收液25.0 mL,抽吸口数为100口.结果 表明,电子烟气溶胶中的铬、镍、砷、铅、镉、锑和汞均能得到有效捕集.在优化条件下,铬、镍、砷、铅和镉的线性范围为0.3～ 80 μg/L,锑和汞的线性范围为0.3～ 10μg/L,其相关系数(r2)均大于0.999,检出限为0.69 ～ 1.19 ng/100 puffs,定量下限为2.29 ～ 3.97 ng/1 00 puffs,方法的回收率为96.5％ ～ 103％,相对标准偏差(RSD)为6.6％～14％.使用该方法与法国标准方法对市售的10种电子烟样品进行测定,两种方法的检测数据基本一致.该方法准确、可靠、高效、使用试剂少,可用于电子烟气溶胶中多种重金属的检测.

[目的]了解加热烟草制品(HTPs)气溶胶成分特点.[方法]采用中心切割二维气相色谱-质谱法,对17个典型的HTPs气溶胶成分进行了分析.[结果](1)HTPs气溶胶的主要成分与普通卷烟烟气相近,但释放量较低,其中66.7%的成分种类在HTPs气溶胶中的每口释放量小于卷烟烟气释放量的10%;(2)HTPs气溶胶中占比最高的成分为甘油(35.8%),烟碱(25.7%),1,2-丙二醇(10.8%),乙酸(3.1%),糠醛(3.1%)等;苯甲醇、苯乙醇、茄酮、新植二烯等成分释放量与卷烟烟气较为接近;(3)不同种类HTPs气溶胶主要成分基本一致,但含氧裂解产物和酚类物质的释放量差别较大.

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.

Near-infrared spectroscopy (NIR) models built on a particular instrument are often invalid on other instruments due to spectral inconsistencies between the instruments. In the present work, global and robust NIR calibration models were constructed by partial least square (PLS) regression based on hybrid calibration sets, which are composed of both primary and secondary spectra. Three datasets were used as case studies. The first consisted of 72 radix scutellaria samples measured on two NIR spectrometers with known baicalin content. The second was composed of 80 corn samples measured on two instruments with known moisture, oil, and protein concentrations. The third dataset included 279 primary samples of tobacco with known nicotine content and 78 secondary samples of tobacco with known nicotine concentrations. The effect of the number of secondary spectra in the hybrid calibration sets and the methods for selecting secondary spectra on the PLS model performance were investigated by comparing the results obtained from different calibration sets. This study shows that the global and robust calibration models accurately predicted both primary and secondary samples as long as the ratios of the number of primary spectra to the number of secondary spectra were less than 22. The models performance was not influenced by the selection method of the secondary spectra. The hybrid calibration sets included the primary spectral information and also the secondary spectra; information, rendering the constructed global and robust models applicable to both primary and secondary instruments.

Pigments are important constituents in tobacco, that relate to appearance and quality of tobacco, meanwhile, the degradation products of pigments have great effects on the quality of aroma of tobacco. According to their color and property, pigments are generally divided into three categories; green pigment, yellow pigment and melanin. In growth, chlorophyll is the main green pigment in tobacco, while xanthophyll and carotene are the main yellow pigments in mature tobacco. Melanin consists in the progress of modulation and fermentation when tobacco leaves are ripe. Analysis of pigments in tobacco is important for evaluations of raw tobacco and the tobacco product quality. Traditional analytical methods of pigments in tobacco based on liquid chromatography, normally need long time and complex sample preparation process, while Raman spectroscopic method is simple to operate and takes short determination time, so that it could be able to provide information about molecular functional groups. Accordingly a method of simultaneous detection of lutein and beta-carotene in tobacco was developed with Raman spectroscopy in the present work. A solution of organic solvent extraction from a tobacco sample was enclosed in a glass vial and was detected to collect its Raman spectrum by focusing the laser on the solution inside. The excitation light wavelength was optimized and 455 nm was selected, under which high Raman signals were obtained. Other experiment conditions, including extracting solvent of pigments and the distance between the focal plane and the optical platform were optimized. Because the spectra were measured in different dates and the measurement conditions could change, normalization was used to correctphysical interference due to the changes with a selected internal standard peak from the solvent spectrum. To solve problem of spectroscopic interference due to severe overlap between Raman signals of lutein and (beta-carotene, partial least squares (PLS) was utilized to build multivariate calibration models between Raman intensities and concentrations of pigments. The results showed that the normalization process could help to correct the changes of the measurement conditions, derivative calculations cannot improve the models but the models can be improved significantly by selection of wavelength regions. When spectral regions were selected between 798.2 and 1 752.8 cm(-1) for lutein, regions of 798.2 similar to 1 752. 8 and 2 254.2 similar to 2 784.5 cm(-1) for beta-carotene, the built PLS models showed the best performances with the prediction errors of RMSEP being 6. 68 and 2. 56 mu g . g(-1), respectively. The results indicated that Raman spectra combined with PLS could supply a new way to the quantitative analysis of lutein and beta-carotene in tobacco with advantages of easy operation, short time and reliable prediction.

A new strategy based on sampling error profile analysis (SEPA) combined with least absolute shrinkage and selection operator (SEPA-LASSO) was proposed. LASSO has been proven to be effective for multivariate calibration with automatic variable selection for high-dimensional data. However, in the previous research, the critical process of multivariate calibration by LASSO was an optimization of 1-norm turning parameter for a fixed sample set without considering the behaviors of variable selection by different subsets of samples. In the present work, Monte Carlo Sampling (MCS), the core of SEPA framework, is used to investigate various sub-models. Least angle regression (LAR) is used to solve LASSO, and various LAR iteration including certain number of variables could be obtained instead of choosing the numerical values of 1-norm turning parameters. SEPA-LASSO algorithm consists of plenty of loops. Under the SEPA framework and LAR algorithm, a number of LASSO sub-models with the same dimensions are built by MCS in each loop, the vote rule is used to determine the importance of variables and select them to build variable subsets. After running the loops, several subsets of variables are obtained and their error profile is used to choose the optimal subset of variables. The performance of SEPA-LASSO was evaluated by three near-infrared (NIR) datasets. The results show that the model built by SEPA-LASSO has excellent predictability and interpretability, compared with some commonly used multivariate calibration methods, such as principal component regression (PCR) and partial least squares (PLS), as well as some wavelength selection methods including LASSO, moving window partial least squares regression (MWPLSR), Monte Carlo uninformative variable elimination (MC-UVE), ordered homogeneity pursuit lasso (OHPL) and stability competitive adaptive reweighted sampling (SCARS).

A method combining gas chromatography with quadrupole time-of-flight mass spectrometry has been developed for the simultaneous analysis of multiple pesticide residues in tobacco leaf. The retention index and high accurate masses of ions from the first-stage and the second-stage mass spectra of each pesticide were collected for qualitation and quantification. A total of 115 pesticides were evaluated. The extract from organic tobacco leaf was used as a model matrix. The limit of detection was <10 ng/mL, and the limit of quantification was in the range of 1-20 ng/mL for 95% of the tested pesticides. The correlation coefficients were >0.9900 for all tested pesticides. At three concentrations (10, 50, and 100 ng/mL), most compounds presented satisfactory recoveries ranging from 70 to 120% and good precision <20%. Finally, three tobacco leaf samples collected from a local market were analyzed. A total of three pesticides were found, including dimethachlon, triadimenol, and flumetralin. Each pesticide was confirmed by the presence of three ions at the expected retention index and mass. In conclusion, gas chromatography with quadrupole time-of-flight mass spectrometry appears to be one of the most efficient tools for the analysis of pesticide residues in tobacco leaf.

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.

This paper reported the attempt of endowing activated carbon the capability of selectively adsorption like that of zeolite for the first time. To create the optimal microenvironment in the activated carbon made from coconut shell, the sorbent was carefully modified with moderate ferric acetate through impregnation followed by carbonization, producing lots of ferric oxide extra-fine particles mingled with carbon nanoparticles to reduce the pore size of activated carbon and to increase the surface roughness of pore wall. Consequently, new activated carbon sorbent trapped 60% of tobacco specific nitrosamines in the tobacco extract solution with the concentration of 1796 ng mL(-1), exhibiting the highest capacity (222 mu g g(-1)) to date. Moreover, it showed a zeolitelike selectivity in the liquid adsorption to capture 98.5% of 4-methylnitrosamino-1-3-pyridyl-1-butanone because of the spindly shape of this strong carcinogen. Besides, distinguishable adsorption of tobacco specific nitrosamines from alkaloid by the new activated carbon sorbent in solution was discovered, providing a valuable clue for the development of new selective sorbents in environment protection.

High-throughput spectra data with large number of variables (wavelength) will make the prediction of multivariate calibration model unreliable, in which case, the sparse statistical methods such as least absolute shrinkage and selection operator (LASSO) are gradually being valued by researchers. In this study, a novel variable informative criterion based on weighted voting strategy combined with least absolute shrinkage and selection operator (WV-LASSO) has been proposed. Monte Carlo Sampling (MCS) is used for generating a large number of sub-models. In each Monte Carlo circulation, the regression coefficients and variable selection information of LASSO model will be recorded. In the present work, weighted voting strategy based on regression coefficients information combined with selected variable frequency of all sub-models is used for evaluating the importance of variable. Different from specific methods, variable informative (importance) criterion can be more extensive and flexible for algorithm design. Then an approach called exponentially decreasing function (EDF) is applied to create a variable selection method with WV-LASSO. The performance of this method was evaluated by three near-infrared (NIR) datasets. Compared with some efficient variable selection methods based on different informative criterions including variable importance projection (VIP), Monte Carlo uninformative variable elimination (MC-UVE), randomization test (RT), competitive adaptive reweighted sampling (CARS), stability competitive adaptive reweighted sampling (SCARS), variable iterative space shrinkage approach (VISSA), interval variable iterative space shrinkage approach (iVISSA), LASSO coupled with sampling error profile analysis (SEPA-LASSO) and variable combination population analysis (VCPA), and so forth, the variable selection method proposed in this paper shows better prediction and interpretation ability and has potential for constructing various variable selection methods by combining other selection strategies.

To design new mesoporous sucker-type selective sorbent for controlling environmental carcinogens like tobacco specific nitrosamines (TSNA), polyaniline (PANI) was controlled carefully to grow at different sites such as near the pore opening, in the channel or on the outside of SBA-15 by in one-pot synthetic and post-synthetic methods. The influences of aniline additional order, aniline to organosilicone ratio and with or without template are investigated in order to obtain the optimal growth position of PANI. Different location of PANI on SBA-15 was confirmed by TEM, N-2 adsorption-desorption characterization and zeta potential measurement. PANI grows preferentially in the channel and then near the pore orifice when proper amount aniline is added previous to silicon source. If aniline is added later after the silicon source, PANI will grow mainly on the outside surface of SBA-15. The location of PANI is in the pore entrances once the aniline is put into the solution after template is removed. Resulting composites realize different selectivity for TSNA and tobacco alkaloids. 1P-S15 production possesses a best TSNA adsorptive capacity (23.2%), higher than commercial activated carbon (15.5%). FTIR spectrum of TSNA in 1P-S15 and quantum calculations demonstrated that the adsorption of TSNA is controlled by hydrogen bonding.

In order to explore relationships between heavy metal migration ratios in mainstream cigarette smoke and their forms in tobacco leaves,contents of different heavy metals (Cr、Ni、As、Se、Cd),their four forms,corresponding unblended mainstream cigarette smoke and TPM in 24 samples from different areas and different parts were studied.Statistical analysis of data was conducted by using least square method and advantage analysis method,and the influence rule of different forms of heavy metals on their migration ratios in mainstream smoke was revealed.Results showed that effects of different forms of heavy metals and TPM on their migration rates in mainstream smoke were in the following order,Cr:fraction of soluble state(inorganic state) (+) ＞fraction of insoluble state (-) ＞TPM (+);Ni:fraction of organic state (+) ＞ fraction of inorganic state (-) ＞fraction of insoluble state (+) ＞ TPM (+);As:TPM (+) ＞ fraction of organic state (+) ＞fraction of inorganic state (+) ＞ fraction of insoluble state (-);Se:fraction of inorganic state (+) ＞TPM (+) ＞ fraction of insoluble state (-) ＞ fraction of organic state (-);Cd:TPM (+) ＞ fraction of organic state (-) ＞ fraction of insoluble state (+) ＞ fraction of inorganic state (+).The plus or minus in the bracket stands for the positive or negative correlation.A theoretical explanation of the above results was proposed by taking into consideration the combustion mechanism of cigarettes,physical properties and occurrence forms of heavy metals and other factors.

To meet the requirement of selective removing environmental carcinogen, elaborated microporous interspaces were successfully fabricated inside the channel of mesoporous silica SBA-15. The discarded cigarette filters (CF) and ferric nitrate solution were infused into SBA-15, and carbonized to form carbon and FexO particles tailoring the tortuosity of mecsoporous channels and provide the necessary electrostatic interaction towards tobacco specific nitrosamines (TSNA) in solution. Besides, the carefully modified SBA-15 displayed evidently selectivity towards 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) and the representative sample Fe0.9CF1.2/S15c owned excellent performances in various tobacco solutions, with the high NNK-selectivity up to 58%, same as that of HZSM−5 zeolite. This strategy created new sorbents combining the high capability of mesoporous silica and the selectivity of microporous zeolite, giving certain enlightenment for new functional materials and environmental protection.

In order to improve evaluation of uncertainty in measurement of physical characters of cigarettes,and to explore feasibility of uncertainty evaluation by Robust Statistics-Iterative method,laboratory quality control data were used to assess uncertainty in measurement of weight,circumference,draw resistance,hardness of cigarettes.Results showed that:uncertainty for weight,circumference,draw resistance and hardness by Robust Statistics-Iterative method were 0.010g,0.04mm,28.0Pa and 5.3％.Uncertainty in measurement of weight,circumference,draw resistance and hardness by bottom-up method were 0.012g,0.04mm,32.0Pa and 6.8％.The result by Robust Statistics-Iterative method reflected long-term detecting level of a laboratory,showing the convenience of this method.

A new strategy named Sampling Error Profile Analysis (SEPA) is proposed in the optimization for some parameters in piecewise direct standardization (PDS), such as the number of principal components and window size, and the evaluation for the calibration transfer. Partial least squares (PLS) with mean-centering is used in PDS for calibration transfer. Random re-sampling is carried out in SEPA to obtain a series of subsets and build same number sub-models that produce corresponding number root mean square errors (RMSE), of which the mean value and standard deviation are calculated. To take both accuracy and stability into account, the sum of the mean value and standard deviation are used for parameter optimization and model evaluation. The performance of the proposed strategy has been tested on two data sets: a ternary mixture dataset and a corn dataset. Compared with PDS, SEPA-PDS obtained lower prediction errors, indicating that the transfer model would be more robust and effective when using the parameters optimized by SEPA. Compared with other two commonly used calibration transfer methods of slope and bias correction (SBC) and spectral space transformation (SST), SEPA-PDS acquired more satisfactory results.

The combination of multiple heart-cutting two-dimensional liquid chromatography (MHC-LC/LC) and quadrupole-orbitrap high-resolution mass spectrometry (HRMS) for simultaneous determination of the aflatoxins and ochratoxin A in snus is presented in this work. A C18 capillary column was used as the first dimension (1D) to isolate the aflatoxins and ochratoxin A from the complex matrices; then, a 2-position/10-port high-pressure valve equipped with two 60 μL loops was employed to transfer the heart-cuts of 1D-LC into a pentafluorophenyl (PFP) column for the second dimension (2D) separation. With the better separation of the MHC-LC/LC system, the sensitivity of the method was improved, which is essential for the trace mycotoxins analysis. Furthermore, HRMS performed in parallel reaction monitoring mode was employed to eliminate the interferences, and the sample pretreatment procedure was simplified. A new approach utilizing ethyl acetate with 1% formic acid/water solution was adopted to extract aflatoxins and ochratoxin A in snus, which provided parallel recoveries for aflatoxins and ochratoxin A with higher responses in comparison with the QuEChERS method. A dynamic range between 0.2 and 20 μg/kg was achieved with LOQs of 0.05 μg/kg for aflatoxin B1, 0.1 μg/kg for aflatoxin B2, G1, G2, and 1.0 μg/kg for ochratoxin A in dry mass of product. The results revealed that the established method exhibited good repeatability and recovery and could be used as a rapid and reliable approach for routine analysis of aflatoxins and ochratoxin A in snus.

To meet the requirement of capturing tobacco-specific nitrosamines (TSNA) for environment protection, a unique microenvironment was carefully created inside the channels of mesoporous silica MCM-41. In situ carbonization of template micelles at 923 K, combined with the excess aluminum used in one-pot synthesis of MCM-41, is adopted to tailor the tortuosity of mecsoporous channels, while loaded metal oxides (5 wt %) and the Al component in the framework are employed to exert the necessary electrostatic interaction toward the target carcinogens TSNA in solution. The elaborated microenvironment created in mesoporous sorbents was characterized with XRD, N2 adsorption-desorption, TEM, XPS, and TG-DSC methods. Various solutions of Burley- and Virginia-type tobaccos were used to assess the adsorption performance of new mesoporous sorbents, and the influence of the solid-to-liquid ratio, adsorption time, and loading amount of CuO on the adsorption was carefully examined. The representative sample 5%Cu/AM-10c could capture 27.2% of TSNA in Burley tobacco solution, and its capacity reached 0.3 mg g-1 in Snus tobacco extract solution, offering a promising candidate for the protection of the environment and public health.

In order to improve quality of cigarettes,the effect of citric acid on nicotine and aroma components content was studied.Five different concentrations of citric acid solution,i.e.0.5％,0.9％,1.3％,1.7％,and 2.1％ (w/w),were prepared and evenly sprayed on cut tobacco.After balancing the system for 48 h,tobacco was dried at set conditions (temperature 110 o C,air velocity 1.57 m/s and rotating speed 12 r/min) at moisture content of 12％-13％,and then extracted with tert-butyl methyl ether and determined by GC/MS.Results showed that:1) When added at 0％ to 0.5％,citric acid and ketones and alcohol showed positive correlation and when added with over 0.5％ it showed negative correlation.2) Content of nicotine in dissociative state was continuously decreased,after adding citric acid to the system.Appropriate amount of addition of citric acid into tobacco was helpful to enhance aroma components,improve the smoking quality,and control nicotine content.

In order to investigate the influences of activated carbon quantity in cigarette filter on the release of some harmful components in mainstream cigarette smoke, cigarette filters with activated carbon added at 0, 1, 2, 3, 4 mg/mm were prepared. Ion molecule reaction mass spectrometry (IMR-MS) coupled with an RM20H rotary smoking machine was adopted for on-line determination of nitrogen oxides, alkenes, benzene series, aldehydes and ketones on puff-by-puff basis. The results showed that: 1) When added at 3 or 4 mg/mm, the total release of the above harmful components in mainstream cigarette smoke were decreased by 8%-62%. 2) There was an“ignition (or the so-called 1st puff high) effect”for the release of isoprene, 1,3-butadiene and benzene, generally their release in mainstream smoke decreased post first puff then increased slowly with the proceeding puffs. 3) For unperforated filter cigarettes, these reduction effects of activated carbon were more pronounced at the addition of 3 mg/mm, and the total release of the harmful components in mainstream smoke was decreased by 21%-61%. For perforated filter cigarettes, the puff-by-puff release of the target analytes in mainstream smoke was lower at the addition of 4 mg/mm, and the total release of toluene, aldehydes and ketones decreased by 34%-62%.

目的:以信息化平台建设思路为借鉴,针对上海烟草集团有限责任公司业务范围内的近红外检测管理现状,提出“动态建模,网络共享,全程管控”的网络化管控体系,保证近红外检测数据质量.方法:构建烟叶近红外网络检测、管控和分析平台体系,该体系主要由模型构建和管控、检测数据共享、检测过程网络化管控、设备远程监控和实验室综合能力评价5部分组成.结果:近红外快速检测及管控网络化体系的构建,可以满足企业广域范围内大规模烟叶快速检测的实际需求,并保证检测数据的质量稳定性.结论:基于网络化管控思想提出的烟草近红外检测管理的“互联网+”新模式,为烟叶品质评价技术发展,促进烟草企业产品研发科技创新提供了有效的技术支撑.