离子色谱法测定卷烟主流烟气中NO_x与烟丝中NO_3~-含量

<正>烟气中的氮氧化物(NOx)大部分来源于烟草中的硝酸盐(NO3-)[1],一方面由于硝酸盐热分解产生氧气,卷烟中硝酸盐含量增加有助于提高卷烟燃烧性,另一方面由于卷烟主流烟气中NOx的含量主要和烟丝中的NO3-相关[2],随着烟草中硝酸盐含量的增加,主流烟气中N2O、NO、NO2等氮氧化物的释放量也随之增加,NOx是卷烟烟气中主要有害成分之一,被列入了"Hoffmann有害成分名单"     

超临界流体色谱与气相色谱-质谱联用测定卷烟主流烟气中醛酮类化合物的研究

建立了一种卷烟主流烟气中醛酮类香气化合物的超临界流体色谱/气相色谱-质谱测定方法。将捕集卷烟主流烟气粒相物的剑桥滤片用超临界流体萃取醛酮类香气成分后,通过配备高效分离柱的超临界流体色谱(SFC)先对香气成分进行划段,分离后的各段馏分再用GC-MS分析。结果表明:经SFC分离后的各段化合物之间基本不重叠,解决了GC-MS峰容量有限的问题,且分离出的醛酮类香气成分数量远多于直接进样分析法;样品直接进样后经GC-MS分析仅鉴定出29种醛酮类化合物,其中醛类7种、酮类22种;而经SFC分段后再用GC-MS分析,可鉴定出57种醛酮类化合物,包括13种醛类和44种酮类。3种不同焦油量卷烟主流烟气中醛酮类化合物种类和含量存在较大差异,每种卷烟主流烟气中分别含有不同特有醛酮类化合物。该研究为卷烟主流烟气中醛酮类香气成分的测定提供了新方法。     

液相色谱-质谱联用测定卷烟主流烟气中的吡啶等氮杂芳烃

建立了测定卷烟主流烟气中的吡啶、2-甲基吡啶、4-甲基吡啶和喹啉等半挥发性氮杂芳烃的液相色谱-串联质谱法(LC/MS/MS)。采用甲醇吸收法从主流烟气中收集目标分析物,利用Zorbax的色谱柱SB-AQ(4.6 mm×150 mm,5μm,C18)为分离柱,乙腈与乙酸铵缓冲液作为流动相进行梯度分离;质谱采用MRM多反应监测模式。检测了不同品牌卷烟在ISO抽吸模式下主流烟气中吡啶等的含量。结果表明,该方法的线性相关系数均为0.999,检测限范围在3.36~13.1 ng/cig之间,所有分析物的相对标准偏差(RSD)小于7.2%,方法适用于卷烟主流烟气中吡啶类化合物的分析测定。     

气相色谱-质谱法测定卷烟主流烟气中百秋李醇和广藿香酮的转移率

采用水蒸气蒸馏法从广藿香中提取精油,将广藿香精油用无水乙醇稀释成0.1%(质量分数)的溶液,按0.03%(精油与烟丝的质量比)的加入量均匀喷加到卷烟烟丝上,卷制成烟支。烟支抽吸完毕后,立即将滤片放入30 mL乙醇中,室温下超声萃取30 min,取2 mL上层清液,经0.45μm有机滤膜过滤后,进行气相色谱-质谱分析。百秋李醇和广藿香酮的线性范围均为0.050~2.00mg·L~(-1),检出限(3s)分别为0.09,0.06μg·支~(-1),加标回收率在90.0%~103%之间,日内和日间测定值的相对标准偏差(n=6)均小于4.0%。应用该方法测得卷烟主流烟气中百秋李醇和广藿香酮的转移率分别为11.82%,19.71%。     

气相色谱-质谱法分析卷烟烟丝和“九曲红梅”红茶样品在加热不燃烧条件下释放出的挥发物及用掺入红茶的烟丝制卷烟的初步探讨

将"九曲红梅"红茶(以下简称红茶)与卷烟烟丝样品分别经过粉碎并通过0.177mm网筛,制成分析用样品。称取0.2mg样品,在裂解炉中,温度为200℃的条件下,在氦气氛围中,样品挥发性成分瞬间气化,由载气带入气相色谱-质谱仪器系统,经分离和测定,得到了两种样品在此条件下所释放出成分。烟丝样品在此加热不燃烧条件下,释放的物质主要有人为添加的发烟剂丙三醇(59.34%),以及其本身的组分烟碱(20.34%)、3-丁炔-1-醇(4.32%)、5-羟甲基糠醛(3.23%)和2,3-二氢-3,5-二羟基-6-甲基-4(H)-吡喃-4-酮(2.12%)等。红茶样品中释放出的主要成分有咖啡因(86.23%)以及16种低含量特征组分。将此红茶样品按质量百分比为5%,10%,30%的比例加入卷烟烟丝中,并测定其在加热不燃烧的条件下释放物质量的变化,并结合感官评价。结果发现:混入不同比例红茶的烟丝,加热后释放出的气体中咖啡因的含量按茶叶的配比量的增加依次为0.71%,1.96%,7.23%;感官评价表明红茶加入卷烟烟丝中,提升了卷烟烟气的优雅感,强化了卷烟的果香、甜香、花香等香韵,提升了香气量和香气丰富性,细腻柔和烟气,改善余味,增强回甜感。当茶叶的加入量为10%时,在余味和口感上有较好的效果,具有全面提升感官品质的功效,整体抽吸舒适性和协调性较好,香气的质和量适中。     

液相色谱-串联质谱法测定卷烟主流烟气中的氨基甲酸乙酯

建立了高效液相色谱-串联质谱法测定卷烟主流烟气中氨基甲酸乙酯含量的分析方法。采用剑桥滤片捕集卷烟主流烟气中的氨基甲酸乙酯,以乙醇为萃取溶剂,振荡技术提取滤片中的目标物,探讨了洗脱溶剂种类、用量及不同类型固相萃取小柱对目标物的净化效果。在优化实验条件下,方法在6～720μg/L范围内具有良好的线性关系,相关系数(r2)为0.999 9,平均加标回收率为93.7%～99.8%,日内重复性RSD小于6%,日间重复性RSD小于5%,定量下限(LOQ)为0.26 ng/cig。该方法准确、灵敏、重现性好、溶剂用量少,适合于卷烟主流烟气中氨基甲酸乙酯含量的测定。     

离子色谱法及聚类分析研究主流烟气中的有机酸

建立了超声辅助萃取-离子色谱法同时测定卷烟主流烟气中主要有机酸的方法.采用20 mL 30 mmol/L J NaOH溶液在50℃下对捕集了卷烟主流烟气的剑桥滤片超声萃取50 min,AS11-HC分离柱、Ion AG11-HC保护柱、ASRS-ULTRAⅡ抑制器,KOH溶液为淋洗液,用电导检测器同时测定了卷烟主流烟气中的乳酸、甲酸、乙酸、丙酸、苹果酸和草酸的含量.方法的线性范围1.0～400 mg/L,相关系数为0.9990～0.9995,相对标准偏差1.4%～4.8%,检出限0.03～0.09 mg/L,回收率为92%～104%.采用此方法测定了19种不同规格卷烟样品主流烟气中6种有机酸的含量,并且以6种有机酸为指标对样品进行了聚类分析.结果表明,6种有机酸的含量分布特征可反映不同等级卷烟产品的特性,可用于不用等级卷烟产品的比较和分类.     

细支卷烟中5种树苔香味物质的气相色谱-质谱法测定

为了评价细支卷烟中树苔香味物质从烟丝向烟气的迁移情况,建立了气相色谱-质谱联用(GC-MS)选择离子法测定卷烟烟丝和烟气中苔黑酚单甲醚、苔黑酚、β-苔黑酚羧酸甲酯、苔黑酚羧酸乙酯和十六酸乙酯的检测方法。考察了萃取溶剂、萃取时间和基质效应对分析结果的影响,最终确定以乙酸乙酯作为萃取溶剂,并使用基质匹配标准溶液进行外标法定量。5个目标物在0. 02～2. 0 mg/L的质量浓度范围内线性关系良好(r~2 0. 996)。在烟丝中,检出限(S/N=3)和定量下限(S/N=10)分别为0. 79～3. 0 ng/m L和2. 6～10. 0 ng/m L,平均加标回收率为90. 5%～103%,相对标准偏差(RSDs,n=6)为2. 3%～12%;在烟气中,检出限(S/N=3)和定量下限(S/N=10)分别为0. 60～2. 9 ng/m L和2. 0～9. 6 ng/m L,平均加标回收率为85. 6%～104%,相对标准偏差(RSD,n=6)为1. 6%～9. 3%。结果表明,该方法简便、灵敏、线性关系好,能满足卷烟烟丝和烟气中5种目标物质的测定要求。运用该方法对烟丝和烟气中5种树苔成分的含量进行测定,并评价了其由细支卷烟的烟丝向烟气的迁移率。     

气相色谱-质谱联用法测定卷烟主流烟气中的呋喃

建立了气相色谱-质谱联用(GC/MS)测定卷烟主流烟气中呋喃的方法。方法以N,N-二甲基甲酰胺为吸收液,用两个串联的吸收瓶捕集主流烟气中的呋喃,HP-PLOT Q毛细管柱分离,选择离子监测,外标法定量。两个串联吸收瓶对主流烟气中呋喃的有效捕集率达99%以上;在0.05~2.5μg/m L的浓度范围内,回归方程线性关系良好(R2=0.9999),检出限(LOD)和定量限(LOQ)分别为0.02μg/支和0.06μg/支;平均加标回收率在93.3%~98.1%之间,RSD小于4%,5 h内样品溶液中呋喃含量的变化率小于6%;用本方法对10种卷烟样品进行测定分析,呋喃的含量在7.57~21.15μg/支之间。     

气相色谱质谱法测定6种加香目标物质的含量及对烟丝加香均匀性的评价

建立了一种运用气相色谱-质谱联用技术(GC-MS)同时测定卷烟烟丝中呋喃酮、异戊酸异戊酯、麦芽酚、薄荷醇、乙基麦芽酚和茴香脑6种烟用加香目标物的检测方法。试样用二氯甲烷溶液振荡提取,旋转蒸发仪浓缩,气相色谱-质谱联用仪检测分析。分别对样品量、萃取溶剂和萃取时间等前处理条件进行了优化。该方法的线性相关系数r均在0.998以上,采用SIM法定量分析,其平均加标回收率为86%～92%,相对标准偏差(RSD,n=6)为4.7%～7.1%,检出限(S/N=3)和定量下限(S/N=10)分别为0.014 7～0.0746μg/g和0.048 9～0.248 8μg/g。结果表明,该方法简便、灵敏度高、线性关系好,能满足同时测定烟丝中此6种加香目标物质的要求。方法还通过测定烟丝样品中加香目标物的含量及其含量的RSD值对卷烟制丝工艺加香的均匀性进行了评价。     

Determination of ammonia in tobacco and smoke

A gas chromatographic method has been developed for the determination of ammonia in tobacco and smoke. Ammonia is liberated from tobacco by a microdiffusion technique using a Conway diffusion cell. Bubbler traps containing dilute sulphuric acid are used to collect the ammonia from smoke.     

Tobacco smoke chemistry. 2. Alkyl and alkenyl substituted guaiacols found in cigarette smoke condensate

A series of alkyl and alkenyl substituted guaiacols, which comprise a group of biologically and organoleptically active compounds, have been synthesized. Mass spectra and GC retention times for these have been recorded and compared with those obtained for constituents of a weakly acidic fraction of smoke condensate derived from American blend type cigarettes. On the basis of these results, 25 guaiacols have been identified, 18 of which have not been detected in tobacco smoke condensate previously.     

Tobacco smoke chemistry 3. Aromatic acids of cigarette smoke condensate

A fraction containing mainly aromatic acids has been isolated from cigarette smoke condensate. Gas chromatographic and mass spectral analysis of the corresponding methyl esters and comparison with reference compounds, many of which were synthesized for this purpose, made possible the identification of 27 constituents (Table 1). Eighteen of these have not been detected in tobacco smoke condensate before.     

Sampling and determination of hydrogen cyanide in cigarette smoke

A method for sampling and determination of hydrogen cyanide in cigarette smoke is described. Cigarette smoke is filtered through a glass fiber filter paper, and only gaseous compounds, such as hydrogen cyanide, are collected in a dilute sodium hydroxide solution. The cyanide is determined spectrophotometrically at 550 nm by the isonicotinic acid–pyrazolone method. Maximum absorbance is achieved within 10 min at room temperature, and remains constant for about 20 min. Beer’s law is obeyed in the range 0.04∼0.80 μg mL^–1 cyanide, with a molar absorptivity of 3.48 × 10⁴ L mol^–1 cm^–1. Received: 30 November 1998 / Revised: 21 April 1999 / Accepted: 30 April 1999     

Sampling and determination of hydrogen cyanide in cigarette smoke

A method for sampling and determination of hydrogen cyanide in cigarette smoke is described. Cigarette smoke is filtered through a glass fiber filter paper, and only gaseous compounds, such as hydrogen cyanide, are collected in a dilute sodium hydroxide solution. The cyanide is determined spectrophotometrically at 550 nm by the isonicotinic acid–pyrazolone method. Maximum absorbance is achieved within 10 min at room temperature, and remains constant for about 20 min. Beer’s law is obeyed in the range 0.04∼0.80 μg mL^–1 cyanide, with a molar absorptivity of 3.48 × 10⁴ L mol^–1 cm^–1. Received: 30 November 1998 / Revised: 21 April 1999 / Accepted: 30 April 1999     

Chlorine and bromine contents in tobacco and tobacco smoke

The chlorine and bromine contents in tobacco and tobacco smoke in both the particulate and gaseous phases were studied by neutronactivation analysis. Methyl chloride and methyl bromide concentrations were measured in the gaseous phase by gas-liquid chromatography — mass spectrometry. The chlorine and bromine contents in nine brands of cigarettes were on the average as follows: Tobacco—6600 ppm chlorine and 110 ppm bromine. Cigarette smoke, particulate phase—68 g chlorine and 1 g bromine per cigarette. Cigarette smoke, gaseous phase—90 g chlorine and 5 g bromine per cigarette. In the gaseous phase methyl chloride accounted for 60% of the total chlorine and methyl bromine for 80% of the total bromine.     

Analysis of aromatic amines in cigarette smoke

A method for the analysis of o-toluidine, o-anisidine, 2-naphthylamine, and 4-aminobiphenyl in cigarette mainstream smoke has been developed, which combines the sensitivity of their pentafluoropropionyl (PFP) derivatives in negative ion chemical ionization (NICI) mode with the selectivity of the gas chromatography/tandem mass spectrometry (GC/MS/MS) technique. The use of four deuterated analogues as internal standards along with the application of the standard addition method results in accurate and precise results; the interday precision for the aromatic amines was 3-10% and the accuracy ranged from 97-100%. This method was applied to two American-blend University of Kentucky reference cigarettes, eight American-blend market cigarettes, a bright (flue-cured) tobacco cigarette, and an electrically heated cigarette smoking system (EHCSS). For the American-blend cigarettes there was a linear correlation between aromatic amine yields and mainstream smoke 'tar' ('tar' = total particulate matter - (nicotine + water)), whereas the bright tobacco cigarette and the EHCSS demonstrated significantly lower aromatic amine yields on an equal 'tar' basis. The results support the hypothesis that the nitrogen content of the tobacco, and above all the cigarette combustion temperature, are determining factors for the yields of aromatic amines in smoke.     

Analysis of pyridines in mainstream cigarette smoke

A new technique has been developed for the quantitative analysis of pyridines in mainstream cigarette smoke using a GC-MS technique. For analysis, 10 cigarettes are smoked using conditions based on US Federal Trade Commission recommendations. The smoke is collected in a water trap and analyzed using a GC-MS technique. A standard or a fast GC separation can be applied for the analysis. The standard separation was followed by MS detection using selected ion monitoring (SIM) acquisition on a quadrupole instrument. The fast GC was followed by MS detection with total ion acquisition on a time-of-flight instrument. The levels of pyridine depend on the type of cigarette: for a full flavor cigarette pyridine is as high as 18.0 microg/cigarette (cig.). and for an ultra light cigarette is about 3.0 microg/cig. Substituted pyridines vary between 5.0 microg/cig. to 0.1 microg/cig. for a full flavor cigarette, and between 0.2 microg/cig. and a few ng/cig. for an ultra light cigarette. The reproducibility of the technique is very good, with less than 7-8% RSD in both separation procedures for most of the analyzed compounds.     

Determination of polycyclic aromatic hydrocarbons in tobacco smoke

Improvements have been described in the apparatus and methods employed in determining polycyclic aromatic hydrocarbons in tobacco smoke by alumina-column chromatography and automatic ultra-violet spectrophotometry