石楠花提取物挥发性成分分析及在卷烟中的应用

为研究石楠花香味成分,并寻找一种新的天然烟用香料的制备方法,采用同时蒸馏萃取法从石楠花中提取烟用香料,并对提取得到的香料进行了挥发性成分析和卷烟加香试验。结果表明,石楠花中提取物中共鉴定出34种成分,主要为醛、酮、醇和杂环类等重要的烟草香味物质;石楠花提取物可赋予卷烟优雅的香韵,提高烟气温润感,降低刺激性,提高抽吸舒适度。石楠花提取物可作为一种新型的天然香料用于卷烟加香。     

美拉德反应产物对主流烟气碱性香味成分的影响研究

为研究美拉德反应产物对主流烟气中碱性香味成分的影响,在某牌号卷烟空白叶组中添加美拉德反应产物(MRPs),采用溶剂萃取法提取吸烟机捕集的卷烟主流烟气粒相物中的香味成分,对萃取液进行碱性成分分离,建立气相色谱-选择离子监测-质谱(GC-SIM-MS)分析碱性香味成分的方法,对比分析添加MRPs前后卷烟主流烟气碱性香味成分...     

4号溶剂在提取烟草净油中的应用研究

本文讨论了采用4号溶剂提取技术在常温下从香料烟烟末中提取香料烟净油的方法.用气相色谱一质谱联用仪对净油的香气香味成分进行分析鉴定,并用香料烟净油进行了卷烟加香试验.结果表明:①4号溶剂能有效地萃取香料烟的致香成分;②香料烟净油可赋予卷烟优雅的香料烟风格特征,明显地提高香气质和香气量,对杂气和余味也有较明显改善.关建词     

五种胡芦巴浸膏的香味成分分析和卷烟中应用效果评价

采用溶剂萃取法从5种胡芦巴浸膏中提取香味成分,通过全二维气相色谱和飞行时间质谱联用技术对萃取物进行成分分析,比较5种浸膏的香味成分差异,并通过感官评价判断它们在卷烟中的添加效果。结果表明,从5种胡芦巴浸膏中检测出的香味成分存在较大的差异,且在卷烟中的添加效果也各有不同,这些不同是由于香原料来源和处理方式的差异造成的。研究对于胡芦巴以及其他烟用香料单体在卷烟中的应用和品质控制有一定的借鉴意义。     

烟草中致香成分提取方法研究进展

烟草的致香成分是烟草研究的重要领域,是评价烟草质量的重要指标。该文综述了烟草种类和其致香成分,及其提取、分离、分析的方法。为烟草致香成分的研究和卷烟制作工艺的改进提供了研究方法和信息。     

罗望子单体香料开发及在卷烟中的应用研究

为研究罗望子单体香料成分及其对卷烟吸食品质的影响,采用乙醇回流提取法,从罗望子中提取浸膏,幵通过比较不同产地的罗望子,选择云南西双版纳的小粒罗望子作进一步的研究;改进传统的提取方法,采用乙醇重复回流提取法提取罗望子浸膏;对罗望子浸膏具有挥収性的化学成分进行气相色谱质谱分析,鉴定出38种化合物,主要包括5-羟甲基糠醛、D-松醇、糠醛、棕榈酸等。罗望子浸膏应用于卷烟加香试验的结果显示,当加料量为0.2‰时,能增加卷烟香气量和提升香气质,同时能减少刺激性改善卷烟口感。罗望子浸膏含有多种香味成分,在卷烟加香中具有较好的应用价值。     

超临界CO2萃取烟草源香料的夹带剂比较

为烟草高附加值成分提取和烟草源香料制备选择优良夹带剂,分别用5种不同极性夹带剂超临界CO₂萃取废弃烟末,将萃取物进行GC-MS分析,比较不同夹带剂对萃取得率和各类香味物质萃取得率的影响,并进行卷烟加香感官评价试验。使用5种夹带剂后萃取得率和各类香味物质萃取得率均高于无夹带剂模式。这5种夹带剂萃取物以相同加香量添加于卷烟,加香后卷烟主体香韵不变。不同夹带剂对各类化学成分的萃取影响较大,选择相应的夹带剂可对烟草香味成分进行有效萃取;无水乙醇是较优的夹带剂,正己烷更利于烷烃化合物的萃取,二丙二醇和二丙二醇甲醚对烟碱的萃取效果较好。     

白肋烟提取物的分离及在卷烟中的应用

为增强雪茄型卷烟的风格特征,采用沉淀分离、液液萃取、膜分离等方法开展白肋烟提取物的分离及应用技术研究,考察不同分离组分对卷烟感官特性的影响.以感官作用为导向,利用沉淀分离、液液萃取制备的醇溶性组分L2具有增强烟香,降低刺激性,凸显蜜甜香、酸香、烘焙香等作用;GC-MS成分分析结果表明,该组分中关键致香成分的含量大大提高...     

产香酵母菌处理烟叶碎片制备特色烟草浸膏的工艺研究

为利用烟叶碎片制备特色烟草浸膏,采用WY803号产香酵母菌处理烟叶碎片,优化产香工艺制备特色烟草浸膏。采用同时蒸馏萃取法采集烟草浸膏的香气成分,并利用气相色谱-质谱联用进行分析。结果表明,经WY803产香酵母菌处理烟叶碎片后所得到的特色烟草浸膏不仅具有增加烟气浓度、丰富烟香的作用,而且具有提高烟香细腻度和甜润性的作用;并为卷烟香气赋以特殊的醇和的酿甜香味,体现了淡雅香的中式卷烟特点。其优化产香工艺为将烟叶碎片水提物灭菌后,添加10%的高粱粉,接种1%的WY803。在30℃的条件下发酵14天。与未经产香处理的普通烟草浸膏的香味成分比较,该特色烟草浸膏成分中的特征香味成分有:呋喃酮、呋喃醇、苯乙醇、新植二烯、巨豆三烯酮、二羟基紫罗兰酮、2-乙酰基吡咯等。     

不同风格类型卷烟中性香味成分差异化研究

为研究不同风格类型卷烟中性香味成分的差异性,采用同时蒸馏萃取法和气相色谱质谱联用技术对9种不同风格类型卷烟中性香味成分进行测定,并通过方差分析、主成分分析和聚类分析对4种类型香味成分进行分析。由方差分析结果可知,针对类胡萝卜素降解产物、棕色化反应产物、芳香族氨基酸裂解产物的总量在I风格卷烟之间没有显著性差异,并且I风格卷烟棕色化反应产物与其他品类卷烟均存在显著性差异;由主成分分析可知,4大类中性香味成分简化为5个主成分,通过计算中性香味成分在5个主成分上的权重,得出不同风格类型卷烟之间差异主要体现在氧化异佛尔酮、6-甲基-5-庚烯-2-醇、β-大马酮和苯乙醛的含量变化;由聚类分析可知,可将不同风格卷烟分为9类,相同风格卷烟能够被分为一类,不同风格卷烟分类效果良好,表明中性香味成分能够用来区分不同风格的卷烟,方法可以为中式卷烟品类构建以及风格特征剖析提供依据。     

An evaluation of actual and simulated smoke properties

Federal regulations require that aircraft cargo compartment smoke detection systems be certified by testing their operation in flight. For safety reasons, only simulated smoke sources are permitted in these certification tests. To provide insight into smoke detection certification in cargo compartments, this research investigates the morphology, transport and optical properties of actual and simulated smoke sources. Experimental data show the morphology of the particulate in smoke from flaming fires is considerably different from simulated smoke. Although the detection of smoldering fires is important as well, only a qualitative assessment and comparison of smoldering sources was possible; therefore, efforts were concentrated on the quantitative comparison of smoke from flaming fires and smoke generators. The particulate for all three different flaming fires was solid with similar morphological properties. Simulated smoke was composed of relatively large liquid droplets, and considerably different size droplets can be produced using a single machine. Transport behavior modeling showed that both the actual and simulated smoke particulates are sufficiently small to follow the overall gas flow. However, actual smoke transport will be buoyancy driven due to the increased temperature, while the simulated smoke temperature is typically low and the release may be momentum driven. The morphology of the actual and simulated smoke were then used to calculate their optical properties. In contrast to the actual smoke from a flaming fire, which is dominated by absorption, all of the extinction for the simulated smoke is due to scattering. This difference could have an impact on detection criteria and hence the alarm time for photoelectic smoke detectors since they alarm based on the scattering properties of the smoke. Copyright © 2004 John Wiley & Sons, Ltd.     

Particle-Gas Equilibria of Ammonia and Nicotine in Mainstream Cigarette Smoke

The particle-gas equilibria of ammonia and nicotine in mainstream cigarette smoke have been studied by diffusion denuder collection. The surface deposition rate of nicotine is observed to decrease as the smoke traverses the denuder, and this effect is attributed to a changing particle nicotine vapor pressure driven by the measured rapid loss of volatile ammonia from the particles, an interpretation that differs from that of prior studies. The rapid ammonia deposition is observed to be complete at a length-to-flow rate ratio of 28 s/cm 2 for an American blended cigarette, and ～38% of the total ammonia analyzed in the collected smoke appears to be nonvolatile in the aerosol, possibly bound in the particles by reaction with acids. Fitting of a theoretical model that predicts the rapid ammonia loss and changing nicotine vapor pressure to the measurements predicts that the nicotine vapor pressure over the particles in fresh smoke is about 6% of the pure component nicotine value, and the ammonia vapor pressure over the smoke particulate is considerably less than that predicted by its aqueous Henry's law coefficient. Dilution of mainstream smoke enhanced the fractional deposition of both ammonia and nicotine in the denuder tubes and provided a means to estimate the nonvolatile ammonia fraction, which varied considerably in cigarettes made with different tobacco types. Among the different tobacco type cigarettes, smoke ammonia concentration, "smoke pH," and smoke nicotine-to-particulate ratio varied with ammonia and nicotine deposition from diluted smoke when extreme values for an all burley tobacco cigarette were included in the analysis, but no trends were apparent when only the more typical range of the other cigarettes was considered.     

Investigation of smoke gases and temperatures during car fire – large‐scale and small‐scale tests and numerical investigations

The hazards for passengers during vehicle fires result from the increasing temperature and the emitted smoke gases. A fire was set on a car to investigate the development of temperature and of gaseous fire products in the passenger compartment. The study was based on a full‐scale test with a reconstructed scene of a serious car fire. The aim of this work was to identify the conditions for self‐rescuing of passengers during a car fire. A dummy, equipped with several thermocouples, was placed on the driver's seat. Also, the smoke gases were continuously collected through a removable probe sensor corresponding to the nose of the dummy in the passenger compartment and analyzed using Fourier transform infrared spectroscopy. Additionally, several car components were investigated in the smoke density chamber (smoke emission and smoke gas composition). It was found that the toxic gases already reached hazardous levels by 5 min, while the temperatures at the dummy were at that time less than 80 °C. The toxicity of smoke gases was assessed using the fractional effective dose concept. The various experimentally parameters (temperature and smoke gas composition) were implemented into numerical simulations with fire dynamics simulator. Both the experimental data and the numerical simulations are presented and discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

高分子粘结膜与金属化合物对PVC树脂的协同阻燃消烟作用

研究了铝塑复合板中高分子粘结膜与Mg(OH)_2和CaCO_3复合阻燃剂对PVC树脂的协同阻燃消烟作用。通过NBS烟箱等仪器测试的有关参数对PVC体系中的金属化合物及填料的抑烟、阻燃效果进行了分析和研究。结果表明：在高分子粘结膜和金属化合物协同作用下能使烟密度(MSD)和生烟速率显著降低,而且有效地推迟了发烟时间。各种金属化合物对PVC体系的氧指数(LOI)影响不大,对烟密度的影响差异很大。     

CFD modeling approach of smoke toxicity and opacity for flaming and non‐flaming combustion processes

Current engineer's methods of fire safety design include various approaches to calculate the fire propagation and smoke spread in buildings by means of computational fluid dynamics (CFD). Because of the increased computational capacity, CFD is commonly used for prediction of time‐dependent safety parameters such as critical temperature, smoke layer height, rescue times, distributions of chemical products, and smoke toxicity and visibility. The analysis of smoke components with CFD is particularly complex, because the composition of the fire gases and also the smoke quantities depends on material properties and also on ambient and burning conditions. Oxygen concentrations and the temperature distribution in the compartment affect smoke production and smoke gas toxicity qualitatively and quantitatively. For safety designs, it can be necessary to take these influences into account. Current smoke models in CFD often use a constant smoke yield that does not vary with different fire conditions. If smoke gas toxicity is considered, a simple approach with the focus on carbon monoxide is often used. On the basis of a large set of experimental data, a numerical smoke model has been developed. The developed numerical smoke model includes optical properties, production, and toxic potential of smoke under different conditions. For the setup of the numerical model, experimental data were used for calculation of chemical components and evaluation of smoke toxicity under different combustion conditions. Therefore, averaged reaction equations were developed from experimental measurements and implemented in ANSYS CFX 14.0. Copyright © 2015 John Wiley & Sons, Ltd.     

高层建筑火灾时烟气温度扩散的数值模拟

分析了高层建筑火灾期间疏散通道内烟气温度场分布的变化规律.通过建立热平衡差分方程,分析烟气与建筑物墙体的传热过程;建立烟气与空气混合的数学模型,分析烟气在高层建筑横向通道内的扩散过程.通过算例分析了烟气温度与扩散时间和疏散通道长度的变化规律,在烟气扩散过程中烟气温度变化受火源烟气发生量的影响较大,而受建筑墙体与烟气热交换的影响较小.     

阻燃抑烟环氧树脂的合成及其性质

以磷酸、三聚氰胺、尿素为原料制备阻燃抑烟剂聚磷酰氰胺脲,然后将其应用于TDE-85#环氧树脂中,以顺丁烯二酸酐为固化剂制备了阻燃抑烟环氧树脂。研究了阻燃抑烟剂聚磷酰氰胺脲的吸湿性,纯环氧树脂和阻燃抑烟环氧树脂的极限氧指数、UL-94阻燃性、隔热性能、烧蚀速率和透光率等。研究结果表明,聚磷酰氰胺脲对环氧树脂具有非常优异的阻燃、抑烟功效。     

Irritancy of the smoke (non-flaming mode) from materials used for coating wire and cable products,both in the presence and absence of halogens in their chemical composition

Four wire coating materials (two of them based on PVC and the two others based on XLPE) were assessed for the irritancy of their smoke, under non-flaming conditions, by using the respiratory depression method, expressed as the RD₅₀. The DIN 53 436 combustion tube was used as the fire model, at a temperature of 550°C (smouldering mode), and the animal model was the mouse. Animals were exposed for 10 min, at concentrations too low to cause lethality. It was found that there was relatively little difference between the irritancy of all four smokes. This was an unexpected result, since it had been predicted that PVC smoke would be much more irritating than XLPE smoke. In fact, the smoke from the PVC compounds had an RD₅₀ roughly in the range of 100–1000 ppm, while the smoke from the XLPE compounds had an RD₅₀ roughly in the range of 10–100 ppm. This means that PVC smoke is somewhat less irritating than XLPE smoke. The components in the smoke of all materials were determined by a combination of continuous gas analysis, ion chromatography and gas chromatography/mass spectrometry, with the objective of understanding the factors causing the irritancy. Hydrogen chloride, one of the major decomposition products of PVC, is also the most important smoke constituent causing irritancy of the smoke. Its irritancy, however, was insufficient, by a considerable margin, to explain the full degree of irritancy found. The RD₅₀ of HCl is, like that of PVC smoke, in the range of 100–1000 ppm. On the other hand, the only compound found in the smoke of XLPE compounds with an RD₅₀ in the same 10–100 ppm range as he overall smoke is methyl vinyl ketone. Unfortunately, the concentration of methyl vinyl ketone was much too low to account for the irritancy levels encountered. Literature data indicate that polyethylene smoke is rich in long-lived free radicals and that PVC smoke does not contain them. Moreover, such free radicals are associated with various illnesses, particularly with respiratory symptoms. Thus, it is speculated that such free radicals could be the cause of the high irritancy of the smoke from the XLPE wire coating materials.     

Experimental investigation on smoke spread characteristics and smoke layer height in tunnels

A series of experiments were carried out in a model‐scale tunnel with dimension of 6.0 m × 1.0 m × 0.7 m to investigate the smoke spread behaviors and the typical smoke layer height. Alcohol was employed as fuel, and the heat release rate was set to be 9.5, 18.4, 30.1, and 63.5 kW, respectively. The temperature profile in the tunnel was measured, and the buoyant flow stratification conditions were visualized by a laser sheet. The experiment results show that the N percentage rule would greatly influence by subjective factors. As the N (10, 20, 30) value increases, the smoke layer height also increases. The results calculated by the buoyancy frequency method were more accurate. Fan's prediction method (Fan WC, Wang QG, Jiang FH. Concise Guide of Fire Science. He Fei: University of Science and Technology of China Press; 1995.161 p.) does not accurately evaluate the smoke layer thickness in tunnel fire. An enhanced empirical formula for predicting the smoke layer thickness in the one‐dimensional horizontal spread stage was proposed. It is shown that the empirical formula could well predict the smoke layer thickness by comparing with the experimental data of previous studies.     

Effect of altitude on vertical temperature distribution and longitudinal smoke layer thickness in long tunnel fires

Based on large eddy simulation, a series of long tunnel fire experiments with different heat release rates (HRRs) and altitudes were carried out. The vertical temperature and thickness of fire smoke are studied. The simulation results show that the higher the altitude, the lower the flame temperature rise, while the change of smoke plume temperature rise is opposite. The movement of smoke in the tunnel can be divided into four regions, and the smoke layer thickness in the longitudinal direction of the tunnel corresponds to the latter three regions. The thickness in Region II increases along the longitudinal direction, the thickness in Region III is a constant value, and the thickness in Region IV increases along the longitudinal direction. Besides, the change of altitude only has an effect on the smoke layer thickness in Region IV. Then, by considering the altitude, HRR, and smoke layer thickness, and using dimensional analysis, an empirical formula for predicting the smoke layer thickness under the influence of altitude in Region IV was established.