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     

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.     

毛细管气相色谱法测定烟草及烟气中有机氯农药残留量

烟草样品或从卷烟烟气中收集到的固态悬浮颗粒样品以正己烷在索氏提取器中提取,提取液用弗罗里硅土固相萃取净化,所得溶液经蒸缩至5mL后,供气相色谱法测定。采用DB-5弹性石英毛细管柱分离样品,电子捕获检测器检测,共测定了17种有机氯农药(OCP′s),其检出限(3S/N)在0.02～0.10μg.g-1范围内。平均加标回收率为86%～92%,相对标准偏差(n=7)为3.0%～4.1%。     

An improved headspace solid-phase microextraction method for the analysis of free-base nicotine in particulate phase of mainstream cigarette smoke

The content of free-base nicotine in cigarette smoke is a controversial subject, partly due to methodological issues. In this investigation, an improved method to measure free-base nicotine in cigarette smoke using headspace solid-phase microextraction (HS-SPME) combined with GC/MS analysis, was developed and validated for this purpose. Cigarette smoke particulate phase (PP) was collected onto a 44 mm glass fiber filter pad. The pad was cut in halves with one half used to determine the concentrations of total nicotine and water. The remaining half was analyzed by HS-SPME for free-base nicotine. The following factors were found to have a significant impact on the responses of free-base nicotine: SPME fiber type, pre-equilibrium time before HS-SPME, extraction time and temperature, PP water content, and the solvent used for the preparation of standards. It was also found that the impact of PP water content on the determination of free-base nicotine from smoke sample could be corrected by a water correction factor calculated based on an experimentally determined reciprocal model. The precision of the method was evaluated with smoke samples of reference cigarettes: Canadian flue-cured monitor and Kentucky reference 2R4F. The RSD values obtained were in the 12.8-16.8% range.     

沸石在去除卷烟烟气中亚硝胺的应用

吸烟污染;沸石;添加剂;沸石在去除卷烟烟气中亚硝胺的应用     

Determination of gas phase nicotine and 3-ethenylpyridine,and particulate phase nicotine in environmental tobacco smoke with a collection bed – capillary gas chromatography system

A combined sampling and analysis technique for the determination of gas phase nicotine and 3-ethenylpyridine, and of particulate phase nicotine in environmental tobacco smoke with capillary gas chromatography is reported. The major advantage of the technique is that all of the collected particulate phase material is analyzed by thermal desorption of the collected material rather than by analysis of only a fraction of the sample extracted from the collection medium. A Teflon filter microtube is used to collect particulate phase nicotine. This microtube is follwed by a small Tenax sorbent bed to collect gas phase nicotine and 3-ethenylpyridine. After sampling, the Teflon filter is transferred to a clean glass tube and the tube becomes an insert for a modified packed column injector port where the material collected on the filter is heat desorbed to a cold capillary tubing trap. Gas phase nicotine and 3-ethenylpyridine are also transferred from the Tenax to the GC column by thermal desorption from the Tenax sorbent bed. Gas phase nicotine and 3-ethenylpyridine, and particulate phase nicotine are each determined by GC analysis of the desorbed material. Nicotine and 3-ethenylpyridine are quantitated by the use of external standards. This technique is straightforward and can be used for semi-real time determination of both gas and particulate phase compounds in environmental tobacco smoke. The results obtained by this technique compare well with those obtained by sampling with annular diffusion denuders.     

烟用香精的气相色谱法质量控制研究

采用配有氢焰检测器或催燃检测器的气相色谱仪,对烟用香精进行了快速分析。方法操作简便,结果可靠,可作为烟用香精原料、产品质量监控的有效手段。     

7种生物碱在不同粒径卷烟主流烟气气溶胶中的分布研究

建立了烟气气溶胶中7种生物碱的气相色谱-质谱(GC-MS)测定方法,并采用电子低压撞击器(ELPI)分12级捕集烟气气溶胶粒相物,研究了卷烟主流烟气气溶胶中7种生物碱含量和浓度的粒径分布。捕集的气溶胶样品加入氢氧化钠溶液和二氯甲烷进行碱法提取,提取液经DB-5MS弹性毛细管柱分离,选择离子监测模式测定,内标法定量。结果表明:该法检测主流烟气气溶胶中7种生物碱的相对标准偏差(RSD)为2.1%~6.4%,检出限为0.39~14.84 ng/cig,加标回收率为85.5%~124.8%。7种生物碱主要分布于0.144~0.722μm的中等粒径气溶胶粒相物中,在粒径0.431μm的粒相物中含量最高,与捕集的粒相物质量分布一致。7种生物碱在不同粒径气溶胶粒相物中的浓度基本趋于一致,其浓度随气溶胶粒径的分布无特异性。     

卷烟主流烟气粒相物中中性化学成分的全二维气相色谱飞行时间质谱(GC×GC-TOF MS)谱图特征识别

建立了全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)分析卷烟主流烟气中中性化学成分的方法。以较长的弱极性柱HP-5MS(50 m×0.2 mm i.d.×0.33μm)作为第一维柱,较短的薄液膜中等极性柱DB-17MS(1.7 m×0.1 mm i.d.×0.1μm)作为第二维柱,对优质烟叶单料卷烟烟气的中性成分进行定性分析,经过人工纠错等分析初步鉴定出匹配度大于700的1 464种成分,重点讨论了中性香味羰基化合物全二维点阵的谱图特征,为烟气和复杂体系的深入研究提供了方法学基础。     

烟碱的色谱测定

总结了近十多年来色谱法(GC、GC-MS、HPLC和SFC等)测定烟碱的情况，归纳整理了国内外主要杂志报道的有关色谱分析烟草、卷烟及其烟气、空气、农药、鼠脑、唾液、头发、血液、尿等中烟碱的方法，并对色谱分析烟碱的主要方法及其发展前景进行了评述。     

固相萃取-超高效液相色谱法测定卷烟主流烟气中丙烯酰胺

建立了一种固相萃取-超高效液相色谱法(SPE-UPLC)快速检测主流烟气中丙烯酰胺的方法。使用剑桥滤片和吸收瓶捕集主流烟气后,蒸馏水做萃取溶剂,采用C18固相萃取小柱对样品液进行纯化,用UPLC检测,外标法定量。UPLC方法采用ACQUITY UPLCTMBEH C181.7μm 2.1×50 mm色谱柱,柱温30℃,流动相为V(乙腈)∶V(水)=6∶94,流速为0.15 mL/min,紫外检测器(TUV)检测波长为202 nm,分析时间为6 min。烤烟型香烟主流烟气中丙烯酰胺的含量为4.75μg/cig。方法的线性范围为0.1~10 mg/mL,线性相关系数为0.9999;平均回收率为98.7%;检出限为10 ng/mL(S/N=3);相对标准偏差为2.3%。该方法适合主流烟气中丙烯酰胺的快速检测。     

Evaluation of capillary electrophoresis for the analysis of nicotine and selected minor alkaloids from tobacco

Summary Difficulties encountered in the gas or liquid chromatographic analysis of nicotine and other alkaloids in tobacco are largely due to the ionic character of these compounds. The potential of using capillary electrophoresis (CE) as an alternative analytical tool to eliminate these problems was evaluated. Parameters including electroosmotic flow, ionic forms of the analytes, buffer composition and applied voltage were studied using nicotine as a model compound. Ionic forms and electrophoretic mobility, as well as UV absorbance, of nicotine were controlled by varying the pH of an aqueous buffer solution. Thus the separation was optimized based on the characters of alkaloids and the nature of capillary electrophoresis. For tobacco samples in which nicotine accounts for more than 98% of the total alkaloid content, a quick method for the determination of nicotine in an aqueous tobacco extract within 100 seconds can be achieved.     

Determination of tobacco alkaloids by gas chromatography with nitrogen-phosphorus detection

An improved method, gas chromatography (GC) with nitrogen-phosphorus detection (NPD), has been used for determination of alkaloids in green and cured tobacco. Tobacco alkaloids of interest included nicotine, nornicotine, myosmine, anabasine, and anatabine. Tobacco samples were treated with a small quantity of aqueous ammonia solution to "loosen" tobacco tissue and to adjust pH, then extracted with solvent. The composition of the extraction solvent solution affected recoveries of the alkaloids, particularly nornicotine, and also contributed to other phenomena such as carry-over in the injection liner and "quenching" of the nitrogen-phosphorus detector. Use of a packed injection liner (e.g. with Carbowax-KOH on Chromosorb) to reduce carry-over was studied. Quenching of the nitrogen-phosphorus detector was eliminated by reducing the injection volume (i.e. increasing the split ratio), by use of a packed injection liner, and by reducing the amount of pretreatment with aqueous ammonia. A narrow bore capillary column (i.e. 0.18 mm id) was used to improve sensitivity and resolution and to increase the speed of GC analysis. An internal standard, 2,4'-dipyridyl, was used for quantitative measurement of these tobacco alkaloids.     

Simultaneous determination of nicotine and 3-vinylpyridine in single cigarette tobacco smoke and in indoor air using direct extraction to solid phase

The aim of the present study was to develop a new analytical method of chromatographic determination of two important markers of ETS exposure: nicotine and 3-vinylpyridine (3-ethenylpyridine, 3-EP) in mainstream (MS) and sidestream (SS) smoke of one single cigarette and in indoor air using direct solid phase extraction combined with gas chromatography. The method can be utilised for both nicotine and 3-EP determination in SS and MS of one single cigarette as well as it allows for a precise determination of compound distribution in indoor air. The application of the same analytical method for both kinds of samples allows anticipating indoor air distribution of both analysed compounds in a very precise way. The precision of the method (calculated as a relative standard deviation) was 9.78% for nicotine and 2.67% for 3-EP; whereas the accuracy (evaluated by a recovery study conducted at three different levels) was 70.1 and 87.3%, respectively. The limit of detection was 0.06 µg per cigarette for both nicotine and 3-EP. The method was evaluated by determining the compounds of interest in two commercially available brands of cigarettes as well as in the reference cigarettes 3R4F and also in indoor air polluted with tobacco smoke. Determined levels of compounds of interest in MS varied from 586 to 772 (nicotine) µg per cigarette and from 3.5 to 10.7 (3-EP) µg per cigarette. In SS smoke the level varied from 14,370 to 22,590 (nicotine) µg per cigarette and from 185 to 550 (3-EP) µg per cigarette, whereas levels in indoor air polluted with tobacco smoke varied from 50.1 to 157.3 (nicotine) µg m^?3and from 7.7 to 20.8 (3-EP) µg m^?3.     

Orthogonal separations of nicotine and nicotine-related alkaloids by various capillary electrophoretic modes

The migration behaviour of nicotine and related tobacco alkaloids was investigated using three different capillary electrophoretic (CE) modes. Novel separations were achieved both using microemulsion electrokinetic chromatography (MEEKC) and nonaqueous CE (NACE). Improved resolution compared to previous studies was obtained using free-solution CE (FSCE). Each technique resulted in different, orthogonal separation selectivity. The suitability of each method for application to the analysis of nicotine lozenges is discussed. The FSCE method was applied to the analysis of nicotine lozenges due to its compatibility with an established lozenge extraction solvent. The method used gave good injection precision and linearity. Good agreement of CE and high-performance liquid chromatography (HPLC) results was obtained. The CE method is therefore considered suitable for the quantitative determination of nicotine in nicotine lozenges.     

Separation and quantitation of phenolic compounds in mainstream cigarette smoke by capillary gas chromatography with mass spectrometry in the selected-ion mode

Cigarette smoke condensate is a complex chemical matrix and determination of phenolic compounds in it frequently requires extensive and laborious sample preparation. By utilizing derivatization techniques and capillary column gas chromatography with mass spectrometry in the selected-ion mode, separation and quantitation of selected phenolic compounds found in mainstream cigarette smoke can be accomplished with minimal sample preparation. This method has been used to determine concentrations of phenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol and hydroquinone in cigarette smoke condensate from a number of commercially available cigarettes and a new cigarette which heats, but does not burn, tobacco. Unlike tobacco-burning cigarettes, levels of the phenolic compounds in the new cigarette smoke are at or below the detection limits for most of the compounds. This result is attributed to the unique design of the new cigarette.     

Protonating and determining myosmine intactly by association with citrate anion

Myosmine can not be separated from nornicotine, nicotine and anabasine intactly by capillary zone electrophoresis (CZE) with a phosphate buffer. Using citrate solution at pH 6.5 as a CZE buffer, myosmine is protonated intactly by H(+), charged positively and then separated from other tobacco alkaloids on the baseline. Its sensitivity is ten times higher than gas chromatography (GC) with a nitrogen-phosphorus detector (NPD). The mechanism for protonating myosmine intactly is discussed and the utility of the new method is testified, too.     

Simultaneous determination of the tobacco smoke uptake parameters nicotine,cotinine and thiocyanate in urine,saliva and hair,using gas chromatography-mass spectrometry for characterisation of smoking status of recently exposed subjects

A method using gas chromatography (GC)-mass spectrometry (MS) for the simultaneous determination of the smoke uptake parameters thiocyanate, nicotine and cotinine in human tissues is reported. Nicotine, cotinine and thiocyanate, in combination with a phase-transfer catalyst, were extracted from urine, saliva and hair into dichloromethane (DCM). Thiocyanate was alkylated in the DCM-layer to form a pentafluorobenzyl derivative. The biochemical markers in DCM were directly injected into the GC system and separated on a DB-1MS column using a 9.4 min temperature program. The method was validated in urine and saliva between the limits of quantitation (1.0-15 microg ml(-1) thiocyanate, 0.010-3.0 microg ml(-1) nicotine and cotinine in urine, 0.010-1.0 microg ml(-1) nicotine and cotinine in saliva). The calibration curves were found to be linear (r > 0.996), the within- and between-day accuracy's were 83-120%, the repeatability coefficients of variation were 3-20% and the limits of detection were 0.060 ng ml(-1) thiocyanate and 0.60 ng ml(-1) nicotine and cotinine. The results of the analysis of the biomarkers in the urine of 44 volunteers were used to develop a predictive model for smoking status, using discriminant analysis. The classification model correctly classified 93.2% of cross-validated grouped cases. Saliva samples were used to confirm the results of the classification method.     

SnifProbe: new method and device for vapor and gas sampling

SnifProbe is based on the use of 15 mm short pieces of standard 0.53 mm I.D. capillary or porous layer open tubular columns for sampling airborne, headspace, aroma or air pollution samples. A miniaturized frit-bottomed packed vial named MicroSPE was also prepared which served for the sampling of solvent vapors and gases as well as liquid water. The short (15 mm) trapping column is inserted into the SnifProbe easy-insertion-port and the SnifProbe is located or aimed at the sample environment. A miniature pump is operated for pumping 10-60 ml/min of the air sample through the short piece of column to collect the sample. After a few seconds up to a few minutes of pumping, the short column is removed from the SnifProbe with tweezers (or gloved hands) and placed inside a glass vial of a direct sample introduction device (ChromatoProbe) having a 0.5 mm hole at its bottom. The ChromatoProbe sample holder with its glass vial and sample in the short column are introduced into the GC injector as usual. The sample is then quickly and efficiently desorbed from the short sample column and is transferred into the analytical column for conventional GC and/or GC-MS analysis. We have explored the various characteristics of SnifProbe and demonstrated its applicability and effectiveness in many applications. These applications include: the analysis of benzene, toluene and o-xylene in air, SO2 in air, perfume aroma on hand, beer headspace, wine aroma, coffee aroma, cigarette smoke, trace chemical warfare agent simulants, explosives vapors, ethanol in human breath and odorants in domestic cooking gas. SnifProbe can be operated in the field or at a chemical process. The sample columns can be plugged and stored in a small union storage device, placed in a small plastic bag, marked and brought to the laboratory for analysis with the full power of GC and/or GC-MS. Accordingly, we feel that the major and most significant feature of SnifProbe is that it brings the field and process to the laboratory. Thus, SnifProbe can extend the "arm" of the GC and GC-MS laboratory and enable high-quality field and process analysis.     

Starker Tobak

The active ingredient of tobacco, nicotine, is originally biosynthesized by plants as a protection against pests. Nicotine survives the harsh conditions in a burning cigarette and binds to certain acetylcholine receptors in the smoker's nerve system within seconds after the first puff. It is the nicotine that makes smoking so extremely addictive. On the other side, the majority of tobacco‐related diseases are not caused by nicotine but by other smoke components. Therefore smoke‐free products like electronic cigarettes have been developed that potentially pose less risk. It is now up to the individual smoker to make an informed choice between different nicotine delivery products and/or smoking at all.