Chemical Studies on Tobacco Smoke. XLVII. On the Quantitative Analysis of Catechols and Their Reduction

Abstract

A quantitative analytical method has been developed for catechols in tobacco smoke using catechol-¹⁴C as internal standard. Main and sidestream smoke particulates are collected in cold traps, the acidic portion of the particulate matter is neutralized and the catechols are enriched by complexing with boric acid. The concentrate of the dihydroxybenzenes is analyzed by GLC/MS.     

The Distribution of Total Particulate Matter (TPM) And Nicotine Between Mainstream and Sidestream Smoke in Bidis and Cigarettes

ABSTRACT

The mainstream (MS) and sidestream (SS) smoke of three types of popular Indian cigarettes, a brand of low tar Indian cigarettes, a brand of US cigarettes and two brands of popular Indian bidis were analysed for carcinogenic total particulate matter (TPM) and nicotine levels employing standard smoking conditions and/or modified smoking standards.

The analysis clearly demonstrated relatively higher levels of TPM and nicotine in MS of three types of popular Indian cigarettes when compared with a brand of low tar Indian cigarettes or a brand of US cigarettes or reported values for MS of western cigarettes. This was also reflected in MS/SS ratios of TPM and nicotine as TPM and nicotine levels in SS of Indian and US cigarettes were similar, when tested employing standard smoking conditions.

Comparative analysis of Indian bidis/cigarettes and a brand of US cigarettes employing modified smoking standard (i.e. 2 puffs/min instead of 1 puff/min) revealed significantly lower values of TPM and nicotine in SS of Indian bidis when compared with corresponding values in Indian/US cigarettes. This shows that contribution of TPM and nicotine in SS from a single bidi to environmental tobacco smoke (ETS) is very much less than that of a single cigarette, and contribution of SS from Indian and US cigarettes to ETS appear to be similar. Reduced levels of TPM and nicotine in SS of bidis, probably due to lack of added burning agents, result into relatively higher deliveries of TPM and nicotine in MS as reflected by higher MS/SS values.     

Chemical Studies on Tobacco Smoke LXVII. Quantitative Determination of Alkaloids in Tobacco by Liquid Chromatography

Abstract

An HPLC method was developed for the quantitative determination of individual alkaloids of the basic fraction of tobacco extracts. Two reverse phase RP-18 columns were used, eluting with a gradient of aqueous triethylamine phosphate buffer (pH 7.56) and acetonitrile.

The method was optimized and compared favorably with existing quantitative techniques in regard to time factors, sensitivity and accuracy.     

吹扫捕集-气相色谱法测定卷烟主流烟气中挥发酚

提出了吹扫捕集-气相色谱法测定卷烟主流烟气中挥发酚的分析方法,使间甲酚和对甲酚能分离并准确定量.在0.4～200.0 mg·L-1范围内各成分的峰面积与其浓度之间呈线性关系,方法的检出限(3S/N)为1.8～4.2 ng/支;样品的加标回收率为97.9%～101.9%;相对标准偏差(n=6)在2.04%～4.52%之间.     

卷烟主流烟气中挥发性羰基化合物分析研究进展

挥发性羰基化合物是卷烟烟气中主要有害成分之一,在抽吸卷烟的过程中会不同程度地刺激人体的感觉器官和呼吸系统,长期吸入会对人体造成严重的危害。文章介绍了卷烟主流烟气中挥发性羰基化合物的形成机制和前提物,综述了羰基化合物的捕集方法、衍生化和检测手段。     

卷烟主流烟气气相水分的捕集及气相色谱法测定

提出了用剑桥滤片捕集烟气粒相物,以异丙醇和乙醇为吸收液、两级碰撞捕集器串联捕集烟气气相物,用气相色谱法测定主流烟气粒相和气相水分含量的方法。试验结果表明:线性范围为0.8～6.0g.L-1,相对标准偏差(n=5)小于2.5%之间,回收率为93.46%～106.15%。采用该法对7种卷烟主流烟气中粒相和气相水分进行测定,烟气总水分含量为6.77～9.43mg.支-1,其中气相水分约占总水分的65%～75%,表明气相水分是研究卷烟品质的重要参数。     

Quantitative Analysis of Metallic Elements in Tobacco and Tobacco Ash by Calibration Free Laser-Induced Breakdown Spectroscopy

Cigarette smoking may be a substantial source of intake of some hazardous elements to the human health. In this work calibration-free laser-induced breakdown spectroscopy technique was employed to investigate the trace metallic elements (Fe, Ca, Al, Cu, K, Li, Mg, Mn, Na, Sr, Ti, and Zn) concentration in tobacco and tobacco ash. Moreover, variation of metallic elements mass concentration between tobacco and tobacco ash has been observed.     

Determination of Nicotine-Related Alkaloids in Tobacco and Cigarette Smoke by GC-FID

A simple and accurate method, gas chromatography (GC) with flame-ionization detection (FID) has been used for determination of the four main nicotine-related alkaloids in tobacco. Tobacco samples were treated with a small quantity of aqueous ammonia solution, to loosen the tobacco tissue and to convert all alkaloids to free bases, then extracted with 1:3 CH₃OH-CH₂Cl₂. A method for further simultaneous and comprehensive determination of six nicotine-related alkaloids in cigarette smoke was also developed. Because of the complexity of the cigarette smoke matrix and the small amounts of alkaloids, except nicotine, in cigarette smoke, the smoke extract was concentrated after removal of the acidic and neutral fractions. To reduce the adsorption and thermal degradation of alkaloids in the liner, especially for nornicotine, a suitable injector temperature was selected and pulsed injection mode was studied. Different cigarette smokes and tobaccos were analyzed for levels of nicotine-related alkaloids.Revised: 3 January and 21 March 2005     

烟草及烟草制品总挥发酸的测定--连续流动法

采用连续流动方法测定烟草及其制品中的总挥发酸,详细研究了测定条件.结果表明最大吸收波长为350 nm,标准乙酸溶液在0.086～4.0 μg/mL的范围内服从比尔定律,摩尔吸光系数为1.174×104L·mol-1·cm-1,对烟草中挥发酸的检出限为0.012mg/g,相关系数为0.999 5,测定范围为0.12～5.0mg/g.方法具有很好的灵敏度和较高的精密度.     

顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分

提出了顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分。结合信息量最大的原则,确定了固相微萃取时萃取纤维头为碳分子筛/聚二甲基硅烷萃取纤维头,萃取温度为70℃,萃取时间为60min。在气相色谱分离中用Agilent DB-1色谱柱为固定相,在质谱分析中采用全扫描模式。结果表明:共鉴定出107种成分,含量最大的成分是烟碱(18.07%),其次是新植二烯(11.46%),主要的3类挥发性和半挥发性成分依次为苯系物、酮类以及杂环类。     

卷烟主流烟气中NNK测量不确定度评定

对气相色谱-热能分析联用法测定卷烟主流烟气总粒相物中NNK含量的测量不确定度进行评定,分析了NNK含量检测的影响因素,计算了不确定度分量及合成不确定度,当NNK含量测定结果为27．4ng／支时,扩展不确定度为2．0ng／支。     

一种测定主流卷烟烟气中固相自由基总量的新方法

研究了一种准确测定主流卷烟烟气中固相自由基总量的新方法. 通常人们采用剑桥滤片来捕集主流卷烟烟气中的固相自由基, 但它并不适合用于准确测定主流卷烟烟气中的固相自由基的总量, 研究发现有超过20%的主流卷烟烟气中的固相自由基可以透过剑桥滤片. 找到了一种电子顺磁共振波谱(EPR)信号很小的、适合用来捕集主流卷烟烟气中的固相自由基总量的过滤片. 采用了以在相同条件下测得的1,1-二苯基-2-苦基肼基(1,1-Diphenyl-2-picryl-hydrazyl, 简称DPPH)的EPR信号强度与强煤的EPR信号强度相比得到的相对EPR信号强度与自由基的自旋数建立校准曲线的方法来计算烟气固相自由基的量, 降低了使用不同的电子自旋共振波谱仪造成的对同一种检测样品测定结果的差异. 通过不同实验室内和实验室间的验证实验, 证明了此方法有很好的重复性和重现性.     

C3-Cyanation of Pyridines: Constraints on Electrophiles and Determinants of Regioselectivity

Methods for C−H cyanation of pyridines are rare. Here, we report a method for C3-selective cyanation of pyridines by a tandem process with the reaction of an in situ generated dihydropyridine with a cyano electrophile as the key step. The method is suitable for late-stage functionalization of pyridine drugs. The low reduction potential of the electrophile and effective transfer of the nitrile group were found to be essential for the success of this method. We studied the reaction mechanism in detail by means of control experiments and theoretical calculations and found that a combination of electronic and steric factors determined the regioselectivity of reactions involving C2-substituted pyridines.     

河南烤烟精油化学成分的研究

本文论述了采用毛细管气相色谱-质谱法研究河南烤烟精油的化学成分。质谱鉴定了45种化合物。烤烟精油中的主要成分有尼古丁,新植二烯,2,6,11-西柏三烯-4,8-二醇,茄酮,β-大马烯酮和巨豆三烯酮等。     

裂解气相色谱-质谱联用法分析卷烟燃吸产物

应用带有吸附阱的CDS 5200型热裂解仪,在不同的裂解温度条件下对卷烟样品进行裂解处理,所得裂解产物直接引入仪器进行气相色谱-质谱分析,检测其中的特征组分、烟碱、新植二烯及有害物质,所测得结果与按标准GB/T 19609-2004方法测得的结果作比较。结果表明:①有害物质的裂解释出量随裂解温度降低而明显下降;②半挥发性烟碱的裂解释出量与常态卷烟吸燃温度相近的裂解温度下不存在相关性;③非挥发性的新植二烯的裂解释出量随裂解温度升高而降低;④在常态卷烟吸燃温度下,所测得的烟碱及新植二烯的释出量基本相同;⑤主流烟气中烟碱主要通过蒸馏而并非通过裂解释出;⑥卷烟吸燃温度的降低有利于减少有害物质的释出;⑦所提出的裂解处理方法作为卷烟燃吸产物的模拟分析是可行的。     

甲醇溶液直接吸收-离子液体富集-气相色谱-质谱法测定卷烟主流烟气中吡啶、喹啉和苯乙烯

建立了一种收集检测卷烟主流烟气中吡啶、喹啉和苯乙烯的方法,以甲醇(CH3OH)溶液为吸收液,直接收集吸烟机抽吸的卷烟主流烟气,采用[BMIM]PF6离子液体萃取富集,气相色谱-质谱联用(GC/MS)技术定量分析卷烟主流烟气中的吡啶、喹啉和苯乙烯3种半挥发性物质,测定过程简便快速,结果准确可靠。本方法的线性关系良好,相关系数(r2)大于0.9995,吡啶、苯乙烯和喹啉的检出限分别为24.9,9.34和4.05ng/cig(每支烟),相对标准偏差(RSD)小于6.0%,加标回收率在90.6%～107.4%之间。     

主流卷烟烟气中气相自由基测定方法的改进

按照ISO 4387标准进行吸烟, 通过自行研制的捕集装置, 以2-苯叔丁基硝酮(PBN)的四氯化碳溶液捕集气相自由基. 将捕集到气相自由基的溶液先用液氮冷冻, 再定时解冻以抑制其衰减, 并有效地去除氧气对气相自由基定量分析的干扰, 获得理想的测定重复性. 用电子顺磁共振波谱仪(EPR)检测气相自由基, 以2,2,6,6-四甲基哌啶-1-氧(TEMPO)作为标准样品, 以碳酸钙稀释的煤粉作为校正样品, 定量计算气相自由基. 测定方法有较好的重复性和较高的灵敏度, 可以满足日常卷烟烟气气相自由基的定量分析的需要.     

气相色谱-质谱法定性定量分析烟叶挥发性香气成分

本文研究了质谱去卷积算法在化合物结构定性中的作用。采用质谱去卷积和质谱库检索、色谱保留指数、标样定性等相结合的方法从烟叶样品中鉴定出118个挥发性香气成分,其中57个醛酮类化合物、23个醇类化合物、16个含氮类化合物、7个有机酸类化合物、15个其它化合物。采用定量离子进行定量,有效降低了重叠峰干扰,使色谱积分结果更为真实准确。对所鉴定的化合物进行重复性考察,结果表明有60.2%的化合物的相对标准偏差(RSD)小于20%,80.5%的化合物的RSD小于30%。线性响应考察结果表明有80个化合物的线性相关系数(R2)在0.90以上,适合于定性或定量分析。     

滤棒中线纤维化学特性对卷烟主流烟气有害成分释放量的影响

为了研究中线滤棒中线纤维化学特性对卷烟主流烟气中有害成分释放量的影响,采用Boehm滴定法及FT-IR光谱对纤维的基团及数量进行了分析,并结合烟气常规以及主流烟气有害成分释放量的检测探讨了纤维的化学特性与主流烟气有害成分释放量之间的相关性。结果显示：（1）卷烟主流烟气中NH。释放量随着纤维酸性基团数量的增加而降低;HCN释放量随着纤维碱性基团数量的增加而降低;（2）影响苯酚释放量的主要因素是纤维的内酯基,其次是纤维的酸碱性;（3）卷烟主流烟气中巴豆醛的释放量随纤维的氨基基团数量的增加而降低。     

墓头回挥发油化学成分的研究

墓头回也叫箭头风,为败酱科植物异叶败酱[Patrinia Heterophylla Bge.]和糙叶败酱[PatriniuScabra Bge.]的根,能治伤寒、温疟,妇女崩中,赤白带下,跌打损伤等疾病,对艾氏癌细胞有抑制及伤害作用。墓头回挥发油的化学成分尚未见报道。本文采用毛细管气相色谱-质谱法对墓头回挥发油的化学成分进行了研究。色谱分离出50多个组分,质谱确定了其中30个组分的化学成分,占总色谱流出峰面积的56.32％。此外还有10个结构尚未完全确定的倍半萜烯,占色谱总流出峰面积的8.50％;3个倍半萜烯醇,占色谱总流出峰面积的4.71％;2