柠檬酸选择性降低烟气烟碱

研究滤嘴添加剂-柠檬酸对主流烟气的影响,实验结果表明:冷冻干燥法吸附效率明显高于注射添加,冷冻干燥法在不改变烟支物理状态的条件下,能降低烟气的pH值,相对选择性降低主流烟气的烟碱,5mg支/的添加量能降低烟气烟碱高达17.88%,对烟气中的游离烟碱降低更为有效(5mg支/的添加量能降低游离烟碱36.8%)。同时卷烟感官评价结果表明添加柠檬酸对卷烟烟气劲头、刺激、细腻程度、干燥感、杂气等都有一定的改善作用。     

卷烟主流烟气TPM及其pH与烟气烟碱量的关系

研究了16种不同牌号卷烟主流烟气总粒相物(TPM)及其pH与其烟气烟碱量的关系。结果表明,总粒相物与烟气烟碱量之间的关联性比较显著,烟气烟碱量较大的牌号,其烟气总粒相物也较大。该研究对于人们的吸食健康有一定的指导意义。     

卷烟纸助剂pH值对烟气pH值、CO、总粒相物及感官质量的影响

研究了卷烟纸助剂pH值对卷烟烟气pH值、CO、总粒相物及感官质量的影响,结果表明,随着卷烟纸助剂溶液pH值的升高,烟气pH值升高,卷烟主流烟气中的CO及TPM含量随之降低,卷烟纸助剂溶液pH值对卷烟感官质量也有影响,溶液显中性对卷烟抽吸品质较为有利。     

非挥发性有机酸与卷烟主流烟气总粒相物pH关系研究

以国内具有代表性的卷烟为研究对象,分别对卷烟样品的非挥发性有机酸含量和卷烟主流烟气粒相物pH进行了测定,通过数学分析研究了非挥发性有机酸含量对烟气粒相物pH的影响.主流烟气粒相物pH值评价指标与有机酸的关联分析结果表明,苹果酸、十五酸、油酸对主流烟气粒相物pH值相对影响较大.对影响主流烟气粒相物pH值的11种非挥发性有机酸的主成分分析结果表明,亚油酸,油酸,苹果酸,棕榈酸,草酸和亚麻酸对主流烟气粒相物pH值相对影响较大.综上可得,苹果酸和油酸对主流烟气粒相物pH值具有较大影响.     

不同茶叶替代烟叶对咖啡碱烟碱的影响

将不同茶叶直接添加于卷烟烟丝中,收集萃取烟气中的烟碱和咖啡碱,用紫外分光光度法定量分析主流烟气中烟碱以及咖啡碱的变化。结果表明,茶叶能够有效的影响烟气烟碱含量,其中当绿茶添加量为20%时烟气的咖啡碱含量达到最大,同时烟碱含量降到最小。     

氧化镁法处理低浓度SO_2烟气优化试验研究

介绍了氧化镁湿法烟气脱硫工艺。利用小型填料塔对影响氧化镁湿法脱硫效率及工艺关键参数的单因素进行了试验研究(如体系pH值、入口烟气浓度、烟气流量、液气比、温度等)。结果表明:体系pH值、烟气浓度、烟气流量对脱硫效率的影响最为显著;随着体系pH值增大、入口SO_2浓度和烟气流量的增大,出口SO_2浓度显著增大,脱硫效率下降;当吸收液的pH值控制在6.0~6.5、液气比控制在4~5 L/m~3,可以实现90%以上的脱硫效率。     

烟草薄片中烟碱的测定

烟碱在碱性环境下与MnO4-生成绿色产物MnO42-,λmax=604 nm,利用此特性,建立了一种烟碱的分光光度测定方法,并对pH值、高锰酸钾浓度等反应条件进行了优化,表面活性剂的加入提高了测定灵敏度,方法操作方便、测定快速、灵敏度高、稳定性好。     

抽吸方式对卷烟主流烟气总粒相物pH的影响

为考察不同抽吸方式对卷烟主流烟气总粒相物p H和化学成分的影响,采用ISO和Health Canada 2种抽吸方式分别抽吸了7种市售卷烟,然后测定总粒相物和烟碱释放量的差异以及总粒相物p H值的变化。研究表明:与ISO方案相比,采用Health Canada深度抽吸方式,总粒相物和烟碱释放量均有显著提高,但p H的增幅较小。     

主流烟气总粒相物中游离烟碱测定方法综述

烟碱是烟草中特有的物质之一,它在烟气中以游离态和质子态2种形态存在。介绍了自20世纪70年代以来主流烟气总粒相物中游离烟碱的测定方法。测定的原理可以分为计算法、溶剂萃取法和间接测定法3种,3种方法都是根据游离态烟碱和质子态烟碱的不同性质来进行分离。     

含镁废水悬浮物过高的原因分析及处理措施

氧化镁湿法烟气脱硫废水与皂化废水混合处理时造成悬浮物过高,影响混合废水的生化处理。对造成混合废水悬浮物过高的原因进行了分析,考察了提高混合废水的pH值和投加絮凝剂去除悬浮物的效果。试验结果表明,氧化镁湿法烟气脱硫废水中的Mg2+与高pH值的皂化废水混合后产生氢氧化镁晶体,在pH值较低时,氢氧化镁晶体的成核速率大于晶体成长速率,大量细小晶核团聚,不利于沉降,造成混合废水的悬浮物较高。提高混合废水的pH值可提高对悬浮物的去除效果,同时投加JYM絮凝剂可加速悬浮物的沉降速率。当pH值大于11,JYM絮凝剂投加量为200 mg/L时,混合废水的浊度可在30 min内降至5 NTU以下。     

PEG6000／（NH4）2S04双水相同时提取烟叶中茄尼醇和烟碱的研究

探讨TPEG6000／（NH4）2SO4双水相直接提取烟草中的烟碱和茄尼醇。研究烟草在不同的提取时间、不同温度、不同pH值等条件下双水相体系对烟叶中烟碱和茄尼醇的提取率。研究发现,烟草的加入量0．8g,（NH4）2SO4的质量分数为16．7％,提取时间3h,提取温度40℃,pH为7时,烟碱的提取率为3．65％,茄尼醇的提取率为2．11％。     

二次萃取蒸馏法从烟草中提取天然烟碱

烟草中的烟碱用石灰水浸提。在ｐＨ＝１１的条件下,经三氯乙烯二次萃取,常压蒸馏获得烟碱粗品。再在压力为４０～６５ｋＰａ,温度为１６０～１７０℃条件下,减压蒸馏获得天然烟碱,产品含量可达９８％以上,收率达６８７％。     

二次萃取蒸馏法提取废次烟叶中烟碱的研究

采用二次萃取蒸馏法,提取废次烟叶中的烟碱。废次烟叶经过浸提、萃取、硫酸反萃、二次萃取和减压蒸馏等处理以提取烟碱,用紫外分光光度法分析了烟碱含量。结果表明,较佳的工艺条件为:以4.5 g/L的NaOH溶液浸泡粉碎后的烟叶,置于60℃水浴中振荡3.5 h,过滤得浸提液;滤渣再次浸提,并将两次浸提液合并。调节浸提液pH≥13,用正己烷按照体积比1∶2萃取浸提液3次。有机相用20%硫酸溶液反萃,调节pH≥13后,用正己烷二次萃取,合并有机相,减压蒸馏,以回收有机溶剂,残液即为含量40%的烟碱产品,提取率达75%。     

“三丝”掺配对主流烟气游离烟碱/烟碱比值的影响和趋势分析

通过正交设计,研究了三丝掺配(薄片、梗丝、膨胀烟丝与烟丝的掺配)对主流烟气中游离烟碱/烟碱比值的影响。3种掺配原料的影响效应大小为:梗丝效应≈薄片效应膨胀烟丝效应,无显著交互效应。对不同三丝掺配比例下的趋势分析发现,游离烟碱/烟碱比值随梗丝、薄片掺配量增加而增加,且在一定的掺配量范围内呈现变化趋势;游离烟碱/烟碱比值随膨胀烟丝掺配量比例增加而降低,但在少量的掺配量范围内变化趋势不是特别明显。     

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.     

我国烟叶中烟碱的研究现状

总结了我国烟草废弃物的概况和利用状况,对烟草中的化学成分进行了简要概括,重点介绍了烟碱的物理化学性质,综述了目前国内烟草研究所使用的提取分离、检测方法,并对烟草的研究利用价值进行了展望,论述了我国低次烟叶综合利用的重大意义,为烟草和烟碱的综合利用提供参考。     

流动注射电位法测定烟草中尼古丁的研究

以聚苯胺修饰的石墨管电极为基体电极,管内涂渍以硅钨酸为活性物质的聚氯乙烯（ＰＶＣ）膜,构成双膜流通式尼古丁电极,建立了流动注射电位法测定尼古丁的新方法,探讨了实验的最佳条件,用磷酸二氢钠－磷酸氢二钠缓冲溶液合并１．０×１０－５ｍｏｌ·Ｌ－１的尼古丁标准溶液作载液,对１．０×１０－４～１．０×１０－１ｍｏｌ·Ｌ－１的尼古丁溶液有良好线性响应,相关系数０．９９８５。本方法简便、选择性好,进样频率８０次·ｈ－１,适合大批量样品的快速测定,可用于检测烟草中的尼古丁。     

Effects of comsumption of high and low nicotine tobacco byManduca sexta (Lepidoptera: Sphingidae) on survival of gregarious endoparasitoidCotesia congregata (Hymenoptera: Braconidae)

The significance of nicotine in the three trophic level interaction involving tobacco (Nicotiana tabacum), the tobacco hornworm (Manduca sexta), and the parasitoidCotesia congregata was investigated in field plots of two varieties of tobacco which had about a 10-fold difference in their nicotine content. WhileM. sexta mortality, rates of parasitism byC. congregata, and the total number ofC. congregata larvae produced per host were similar on each of the two varieties, the number of parasitoids reaching adult-hood on the low nicotine treatment was nearly twice that on the high nicotine treatment. This difference was due to the significantly greater proportion of parasitoid larvae which failed to emerge from the host or that died prior to pupation after emerging from hosts which fed on the high nicotine variety. A greater proportion of larvae from hosts which fed on the low nicotine tobacco died as pupae. No treatment differences occurred for either sex of the parasitoid in individual dry weight, longevity, or pupal development time, except that female pupal duration was prolonged in the high nicotine treatment. These results support the suggestion that plant allelochemicals, which may function to provide plant resistance against pest herbivores, can be detrimental to natural enemies of the pest.Scientific article No. A4148 of the Maryland Agricultural Experiment Station, Department of Entomology. Research supported by NSF grant BSR-84-00614.     

烟碱提取新方法研究

调节低、次烟叶的含水率,使w(H2O)=12%～13%。在密闭容器中,控制温度540～550℃,使低、次烟叶碳化脱羧。产生的气体和液体用w(H2SO4)=70%的硫酸吸收,可得到w(C10H14N2)=4%左右的硫酸烟碱稀溶液。负压下,将该溶液浓缩至w(C10H14N2)≥20%、用80～100℃的饱和Na2CO3水溶液碱化至无气泡冒出为止,再加入稍过量的Na2SO4·10H2O,使水相形成饱和溶液,密闭、静置24h,即可把烟碱从水相中盐析出来。分出烟碱,在氮气保护下,负压进行两次蒸馏,收集140～148℃/4 0×103Pa馏分,可得w(C10H14N2)=98%以上的烟碱产品,产率在83%以上。提取过程中基本没有三废排放。