Analysis of cigarette mainstream smoke for 1,1-dimethylhydrazine and vinyl acetate by gas chromatography-mass spectrometry

1,1-Dimethylhydrazine, also known as unsymdimethylhydrazine (UDMH) and vinyl acetate (VA), are both classified by the International Agency for Research on Cancer as 2B carcinogens (possibly carcinogenic to humans) and listed as cigarette smoke constituents; however, there is little or no quantitative data available on them. For UDMH in cigarette smoke, neither a yield nor a method has been published. For VA, the most recent information on yields dates back to 1965. To bridge this gap, we have developed new gas chromatographic-mass spectrometric methods for both compounds to determine their yields in cigarette smoke. UDMH is determined by derivatization with 2-nitrobenzaldehyde in methanol and is not found in cigarette smoke at levels above the detection limit of 19 ng/cig. In further experiments, when UDMH is added to the smoke stream or air stream of lit or unlit cigarettes, the derivative 2-nitrobenzaldehyde-2,2-dimethylhydrazone is found only in the air stream of the unlit cigarettes. From this, we conclude that UDMH is either not formed during smoking at all or, if it is, it reacts immediately and quantitatively with other smoke constituents (e.g., aldehydes) and is therefore not detectable in cigarette smoke. VA is determined by trapping in acetone at -78 degrees C and is found at a concentration of 270 ng/cig for a standard reference cigarette with a cellulose acetate filter (the reference cigarette 1 R4F). In the literature, VA is reported at concentrations of 1.6 microg/cig for a cigarette with a cellulose acetate/charcoal filter and 4 microg/cig for a cigarette with a cellulose acetate filter and for an unfiltered cigarette.     

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.     

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。     

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。     

Determination of four tobacco-specific nitrosamines in mainstream cigarette smoke by gas chromatography/ion trap mass spectrometry

A specific and sensitive method was developed and validated to quantitatively analyze four tobacco-specific nitrosamines (TSNAs) in the particulate phase of mainstream cigarette smoke. Cigarette smoke particulate matter was collected according to ISO 4387. The particulate matter was extracted with acetic ether, cleaned up with a Supelclean ENVI-Carb silod-phase extraction (SPE) cartridge, concentrated under the protection of nitrogen and analyzed by gas chromatography (GC)/ion trap mass spectrometry (MS) with a very-low-flow-loss column (VF-17 MS) in MS(n) mode using N-nitrosopentyl-3-picolylamine (NNPA) as an internal standard. TSNAs were identified by chromatographic retention time, matching the spectra of the standards and the samples and the consistency of the ratio of the abundance of the ions detected in the standards and the samples. Limits of detection of each TSNA varied from 0.01 to 0.06 ng/cig. A linear calibration range for this method is large enough to measure TSNA levels in cigarette smoke. The recovery of each TSNA was from 91.5 to 102.7%. The method achieved excellent reproducibility (RSD: 1.8-4.8% for intra-assay, 3.4-7.1% for inter-assay). It also shows no evidence of artifact formation. This method is very suitable for the routine detection of TSNAs in mainstream cigarette smoke.     

固相萃取-气相色谱/质谱联用法测定卷烟主流烟气中的香兰素和乙基香兰素

采用固相萃取-气相色谱/质谱联用技术,建立了一种同时测定卷烟主流烟气中香兰素和乙基香兰素的方法。方法优化了萃取条件,考察了萃取溶剂、萃取时间对检测结果的影响。通过硅藻土固相萃取柱净化并浓缩后,选取DB-HeavyWAX毛细管柱进行目标物分离,以香兰素-d3作为内标,对香兰素和乙基香兰素进行定量分析。结果表明,香兰素和乙基香兰素在浓度0.2~20.0 mg/L范围内具有良好的线性关系,其检出限分别为9.1 ng/支和6.5 ng/支,回收率均在96.3%~107.7%之间。     

卷烟主流烟气中8种羰基化合物的超高效液相色谱测定

建立了超高效液相色谱(UPLC）对卷烟主流烟气总粒相物中甲醛、乙醛、丙酮、巴豆醛等8种羰基化合物的测定方法。采用经2,4-二硝基苯肼酸性溶液处理过的剑桥滤片捕集烟气,再用含2%(体积分数）吡啶的乙腈溶液进行萃取,以KinetexTM C18(150 mm×2.1 mm,2.6 μm）为色谱柱,水-乙腈(35∶65）和水-乙腈-四氢呋喃-异丙醇(59∶30∶10∶1）为流动相梯度洗脱,采用二极管阵列检测器进行检测,分析时间为20 min。结果表明,该方法的相关系数r2≥0.999 97,检出限为25.81~67.74 ng/cig,平均加标回收率为95%~99%,相对标准偏差为1.4%~5.8%。各组分峰分离度高、分析时间短、流动相耗量少、结果准确可靠。用该方法对20种不同卷烟牌号样品中8种羰基化合物的含量进行测定,结果满意。     

Quantitative determination of selected compounds in a Kentucky 1R4F reference cigarette smoke by multidimensional gas chromatography and selected ion monitoring-mass spectrometry

Eight compounds from a Kentucky 1R4F reference cigarette smoke condensate have been determined by selected ion monitoring-mass spectrometry (SIM-MS) to confirm the validity of multidimensional gas chromatography (MDGC) as a quantitative tool in complex mixture analyses. Four electrostatically precipitated smoke condensate samples of 100 cigarettes each are dissolved individually in 25 mL of 2-propanol. The 2-propanol contains two methyl esters (C8 and C14) and seven deuterium-labeled compounds used as internal standards (IS). Analysis of the compounds of interest, pyridine; acetamide; acrylamide; phenol; o-, m-, and p-cresol; and quinoline, is accomplished by using two heartcuts. Heartcut times of the MDGC analysis are selected such that at least one IS is transferred with each group of compounds being analyzed. This study shows that the MDGC technique previously developed and described can be used for quantitative analyses. A comparison is made between the two types of internal standards. The results obtained for both types of internal standards agree within 20% of each other, on the average, with higher standard deviations for approximately 60% of the compounds where methyl esters are used as internal standards.     

Determination of acrylamide formed in asparagine/D-glucose maillard model systems by using gas chromatography with headspace solid-phase microextraction

A gas chromatographic method, along with a headspace solid-phase microextraction (HS-SPME), was developed for the determination of acrylamide formed in Maillard reaction model systems. The developed method was validated by liquid chromatography/mass spectrometry. A headspace sample was collected from an aqueous acrylamide solution (100 microg/mL) by SPME and directly injected into a gas chromatograph equipped with a nitrogen-phosphorus detector. The recovery of acrylamide from an aqueous solution was satisfactory, i.e, >93% under the conditions used. Acrylamide formed in an asparagine/D-glucose (molar ratio, 1/2) Maillard reaction model system heated at 150 and 170 degrees C for 20 min was collected and analyzed by the newly developed method using gas chromatography with nitrogen-phosphorus detection and HS-SPME. The amounts of acrylamide were 318 +/- 33 microg/g asparagine from a sample heated at 150 degrees C and 3329 +/- 176 microg/g asparagine from a sample heated at 170 degrees C. Addition of cysteamine or glutathione to the above model system reduced acrylamide formation. Acrylamide formation was not observed when cysteamine or glutathione was added to asparagine in the above model systems to obtain equimolar concentrations of both compounds. This newly developed method is simple and sensitive, and requires no solvent extraction.     

Determination of seven nitrobenzene compounds in mainstream cigarette smoke with heart-cutting two-dimensional gas chromatography

A heart-cutting two-dimensional gas chromatography (GC) method was developed for the determination of nitrobenzene compounds (NBCs) in mainstream cigarette smoke. For the method, the particulate matter of cigarette smoke was extracted with cyclohexane, purified with a silica solid-phase extraction (SPE) cartridge and analyzed by heart-cutting two-dimensional GC equipped with two electron capture detectors. The heart-cutting two-dimensional GC was achieved by a single-column GC oven equipped with a microfluidic pressure balanced device (Deans switch). Two-dimensional GC was compared to single-dimensional GC and found to be clearly better for the separation of seven NBCs from a complex smoke matrix. The limits of detection ranged from 1.28 to 9.83 ng/mL, spiked recoveries were between 88.3 and 106.8% and relative standard deviation ranged from 2.79 to 12.78%. The NBCs yields of six kinds of Chinese and international cigarettes brands, which were all smoked according to two smoking protocols (International Organization for Standardization and Health Canada Intense smoking regimens), were determined and compared.     

Investigations on the direct introduction of cigarette smoke for trace elements analysis by inductively coupled plasma mass spectrometry

Direct introduction of mainstream cigarette smoke into an inductively coupled plasma mass spectrometry (ICP-MS) has been investigated with respect to its feasibility for on-line analysis of trace elements. An automated apparatus was designed and built interfacing a smoking machine with an ICP-MS for smoke generation, collection, injection and analysis. Major and minor elements present in the particulate phase and the gas phase of mainstream cigarette smoke of 2R4F reference cigarettes have been qualitatively identified by examination of their full mass spectra. This method provides a rapid-screening analysis of the transfer of trace elements into mainstream smoke during cigarette combustion. A full suite of elements present in the whole cigarette smoke has been identified, including As, B, Ba, Br, Cd, Cl, Cs, Cu, Hg, I, K, Li, Mn, Na, Pb, Rb, Sb, Sn, Tl and Zn. Of these elements, the major portions of B, Ba, Cs, Cu, K, Li, Mn, Na, Pb, Rb, Sn, Tl and Zn are present in the particulate phase, whereas the major portion of Hg is present in the gas phase. As, Br, Cd, Cl, I and Sb exist in a distribution between the gas phase and the particulate phase. Depending on the element, the precision of measurement ranges from 5 to 25% in terms of relative standard deviation of peak height and peak area, based on the fourth puff of 2R4F mainstream cigarette smoke analyzed in five smoking replicates.     

Comparison of air‐agitated liquid–liquid microextraction and ultrasound‐assisted emulsification microextraction for polycyclic aromatic hydrocarbons determination in hookah water

In this work, two disperser‐free microextraction methods, namely, air‐agitated liquid–liquid microextraction and ultrasound‐assisted emulsification microextraction are compared for the determination of a number of polycyclic aromatic hydrocarbons in aqueous samples, followed by gas chromatography with flame ionization detection. The effects of various experimental parameters upon the extraction efficiencies of both methods are investigated. Under the optimal conditions, the enrichment factors and limits of detection were found to be in the ranges of 327–773 and 0.015–0.05 ng/mL for air‐agitated liquid–liquid microextraction and 406–670 and 0.015–0.05 ng/mL for ultrasound‐assisted emulsification microextraction, respectively. The linear dynamic ranges and extraction recoveries were obtained to be in the range of 0.05–120 ng/mL (R² ≥ 0.995) and 33–77% for air‐agitated liquid–liquid microextraction and 0.05–110 ng/mL (R² ≥ 0.994) and 41–67% for ultrasound‐assisted emulsification microextraction, respectively. To investigate this common view among some people that smoking hookah is healthy due to the passage of smoke through the hookah water, samples of both the hookah water and hookah smoke were analyzed.     

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.     

卷烟主流烟气中碳中心自由基的自旋标记荧光表征

以自旋标记荧光探针4-((9-acridinecarbonyl)amino)-2,2,6,6-tetramethylpiperidin-1-oxyl(TEMPO-9-AC)研究了卷烟主流烟气中的碳中心自由基。以吸烟机抽吸卷烟,以弱荧光的TEMPO-9-AC作为捕集剂捕集卷烟主流烟气中的碳中心自由基,生成稳定的强荧光的碳中心自由基捕集加合物,以高效液相色谱-三重四极杆串联质谱联用仪(HPLC-MS/MS)对其结构进行了确认,并建立了高效液相色谱-荧光检测(HPLC-FLD)的定量方法。结果表明,方法的检出限为0.318 nmol/cig,相对标准偏差(RSD)为3.5%～9.7%;利用TEMPO-9-AC捕集体系鉴别出了10种碳中心自由基;对5种代表性卷烟烟气中的碳中心自由基进行了定量计算,获得了它们在主流烟气中碳中心自由基的含量数据,并发现碳中心自由基总量与焦油释放量之间具有高度的相关性。本法检出限低,重复性好,适用于卷烟主流烟气中碳中心自由基的结构验证及释放量的检测分析。     

Use of 2-(tert-butoxy)-N-(3-carbamothioylphenyl)acetamide and graphene oxide for separation and preconcentration of Fe(Ⅲ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ) ions in different samples

A simple and selective method using a column packed with graphene oxide(GO) as a solid phase extractant has been developed for the multi-element preconcentration of Fe(Ⅲ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ)ions prior to flame atomic absorption spectrometric determinations.The method is based on the sorption of mentioned ions on synthesized GO using 2-(tert-butoxy)-N-(3-carbamothioylphenyl)acetamide as a chelating agent.Several parameters on the extraction and complex formation were optimized.Under the optimized conditions(pH 6,flow rate 9 mL/min),metal ions were retained on the column,then quantitatively eluted by HNO3solution(5 mL,3.0 mol/L).The preconcentration factor was calculated as250.The detection limits for the analyte ions of interest were found in the range of 0.11 ng/mL(Ni2+) to0.63 ng/mL(Cu2+).The column packed with GO was adequate for metal ions separation in matrixes containing alkali,alkaline earth,transition and heavy metal ions.     

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。     

Capillary gas chromatographic determination of methylglyoxal from serum of diabetic patients by precolumn derivatization using meso-stilbenediamine as derivatizing reagent

Stilbenediamine is used as derivatizing reagent for methylglyoxal (MGo) and dimethylglyoxal for the gas chromatographic (GC) determination of MGo from the serum of diabetic patients and healthy volunteers. The derivatization is obtained at pH 3. GC elution and separation are carried out on an HP5 column (30 m x 0.32 mm i.d.) at column temperature 150 degrees C with a programmed heating rate of 50 degrees C/min up to 250 degrees C, and a total run time of 7 min. The nitrogen flow rate is 5 mL/min and detection is carried out by flame ionization detection. The linear calibration curves are obtained with a range of 0.076-0.760 microg/mL and the detection limit is 25 ng/mL MGo. The amounts of MGo found in the serum of healthy volunteers and diabetic patients are 0.025-0.065 microg/mL and 0.115-0.228 microg/mL, with coefficient of variation 1.3-3.1% and 1.4-3.3%.     

离子色谱法测定卷烟主流烟气中氨含量的不确定度评定

根据《测量不确定度评定与表示》对离子色谱法测定卷烟主流烟气中氨含量的不确定度进行评定,通过分析得出,测量重复性、线性回归方程以及标准溶液的配制是不确定度的主要来源。分析结果结果表明,当卷烟样品主流烟气中氨释放量为12.04μg/支时,扩展不确定度为0.40μg/支,k=2。     

离子色谱法测定卷烟主流烟气中的硫化氢

建立了测定卷烟主流烟气中硫化氢含量的离子色谱法.采用玻璃纤维滤片捕集卷烟烟气粒相物,并用0.5%(体积分数)乙二胺-50 mmol/L氢氧化钠-250 mmol/L乙酸钠溶液萃取粒相物,吸收液吸收气相物中的硫化氢,合并粒相萃取液与气相吸收液,经离子色谱柱分离,以1.5 mol/L氢氧化钠-1 mol/L乙酸钠-2%(体积分数)乙二胺(40∶50∶10,体积比)为流动相,安培检测器检测并施加-100 mv的检测电位.运用方法对12种市售卷烟样品进行了测定,结果表明:方法的线性范围为0.1~5.0μg/mL,检出限为1.03μg/mL,定量限为3.41μg/mL,回收率为102.3%~107.2%,相对标准偏差小于5%.方法处理简单、准确度高,可以用于卷烟烟气中硫化氢含量的测定.     

Rapid and sensitive method for simultaneous determination of six carcinogenic aromatic amines in mainstream cigarette smoke by liquid chromatography/electrospray ionization tandem mass spectrometry

Aromatic amines are one of the sources of carcinogenicity in cigarette and tobacco smoke. Accurate quantification of these chemicals is needed to assess public health risk. A new validated rapid, sensitive and analyte specific liquid chromatography/electrospray ionization tandem mass spectrometric (LC/MS/MS) method has been developed for the simultaneous determination of six aromatic amines in mainstream cigarette smoke using research reference cigarette 2R4F. Three popular Indian brand cigarettes were also analyzed using the same procedure. The limit of detection of this method ranged from 0.04 to 0.59 ng/cig using an injection volume of 7 μl. The identification of each amine was established by chromatographic retention times, analyte specific fragmentation pattern and relative peak area ratios of two product/precursor ion pairs. The method showed excellent reproducibility and was also rapid, selective and robust for aromatic amine determination from cigarette smoke.