Rapid and sensitive method for the determination of propylene oxide in cigarette mainstream smoke by gas chromatography-mass spectrometry

A rapid method using gas chromatography-mass spectrometry for the analysis of propylene oxide in cigarette mainstream smoke is reported. Validation data show the method, which requires a minimum of sample preparation, to be selective, sensitive, reliable, and robust. Propylene oxide is found in the University of Kentucky Reference Cigarettes 1R4F and 2R4F at concentrations of 0.93 and 0.65 microg/cigarette, respectively, with a quantitation limit of 0.135 microg/cigarette.     

Development of solid-phase microextraction followed by gas chromatography-mass spectrometry for rapid analysis of volatile organic chemicals in mainstream cigarette smoke

In this work, a novel, simple and efficient method based on solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed to the analysis of volatile organic chemicals (VOCs) in mainstream cigarette smoke (MCS). Using a simple home-made smoking machine device, extraction and concentration of VOCs in MCS were performed by SPME fiber, and the VOCs adsorbed on fiber were desorbed, and analyzed by GC-MS. The extraction fiber types and the desorption conditions were studied, and the method precision was also investigated. After the investigation, the optimal fiber was divinylbenzene/carboxen/polydemethylsiloxane (DVB/CAR/PDMS), and the optimal desorption condition was 250 degrees C for 3 min. The method precision was from 2% to 11%. Finally, the proposed method was tested by its application of the analysis of VOCs in MCS from 10 brands of cigarettes and one reference cigarette. A total of 70 volatile compounds were identified by the proposed method. The experimental results showed that the proposed method was a simple, rapid, reliable, and solvent-free technique for the determination of VOCs in MCS.     

Isotope dilution gas chromatography-mass spectrometry in the determination of benzene, toluene, styrene and acrylonitrile in mainstream cigarette smoke

A cryogenic trapping method with isotope dilution gas chromatography-mass spectrometry analysis has been developed for the determination of benzene, toluene, styrene and acrylonitrile in mainstream vapor phase cigarette smoke. The method is simple, direct, and quantitative. Vapor phase samples are collected cryogenically in a series of four traps following removal of the particulate phase with a Cambridge filter pad. For all four analytes, 75-85% of the total amounts recovered were found in the initial trap and less than 1% in the final trap. Assessment of instrumental precision by multiple injections of a sample gave relative standard deviations of less than 2%. Linear calibration for all analytes over the analysis range gave an r2 value greater than 0.99 with average relative standard deviations at the mean ranging from 1.4 to 8.2%. The cigarettes analyzed include a reference cigarette (Kentucky 1R4F), a commercial ultra-low "tar" mentholated cigarette, and two cigarettes that heat but do not burn tobacco. The values determined for the four analytes in the 1R4F samples are comparable to reported values of similar cigarettes. The cigarettes which heat rather than burn tobacco yield less of all four analytes compared to the other cigarettes in the study.     

Characterization of complex hydrocarbons in cigarette smoke condensate by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

Gas chromatography-mass spectrometry with electron ionization and positive-ion chemical ionization and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF-MS) were applied for the characterization of the chemical composition of complex hydrocarbons in the non-polar neutral fraction of cigarette smoke condensates. Automated data processing by TOF-MS software combined with structured chromatograms and manual review of library hits were used to assign the components from GC x GC-TOF-MS analysis. The distributions of aliphatic hydrocarbons and aromatics were also investigated. Over 100 isoprenoid hydrocarbons were detected, including carotene degradation products, phytadiene isomers and carbocyclic diterpenoids. A total of 1800 hydrocarbons were tentatively identified, including aliphatic hydrocarbons, aromatics, and isoprenoid hydrocarbons. The identified hydrocarbons by GC x GC-TOF-MS were far more than those by GC-MS.     

Gas chromatography-mass spectrometry of carbonyl compounds in cigarette mainstream smoke after derivatization with 2,4-dinitrophenylhydrazine

An improved gas chromatography-mass spectrometry (GC-MS) method was described for the analysis of carbonyl compounds in cigarette mainstream smoke (CMS) after 2,4-dinitrophenylhydrazine (DNPH) derivatization. Besides formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, methyl ethyl ketone, butyraldehyde, and crotonaldehyde that are routinely analyzed in cigarette smoke, this technique separates and allows the analysis of several C4, C5 and C6 isomeric carbonyl compounds. Differentiation could be made between the linear and branched carbon chain components. In cigarette smoke, the branched chain carbonyls are found at higher level than the linear chain carbonyls. Also, several trace carbonyl compounds such as methoxyacetaldehyde were found for the first time in cigarette smoke. For the analysis, cigarette smoke was collected using DNPH-treated pads, which is a simpler procedure compared to conventional impinger collection. Thermal decomposition of DNPH-carbonyl compounds was minimized by the optimization of the GC conditions. The linear range of the method was significantly improved by using a standard mixture of DNPH-carbonyl compounds instead of individual compounds for calibration. The minimum detectable quantity for the carbonyls ranged from 1.4 to 5.6 microg/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.     

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.     

液相色谱-串联质谱法测定卷烟主流烟气中的四种致癌物

N-亚硝基降烟碱（NNN）、4-（亚硝基甲氨基）-1-（3-吡啶基）-1-丁酮（NNK）、N-亚硝基新烟草碱 （NAT）和N-亚硝基假木贼碱（NAB）是4种广泛存在于烟草和烟气中的致癌物,准确测定其含量对评估其对人体健康的影响有着重要的作用。采用液相色谱-电喷雾串联质谱(LC-ESI MS/MS)技术建立了卷烟主流烟气中NNN、NNK、NAT和NAB的测定方法,并将其用于中国烤烟和混合型卷烟主流烟气的分析。卷烟主流烟气通过剑桥滤片捕集,捕集烟气后的滤片在加入100 μL氘代混合内标后用10 mL 100 mmol/L醋酸铵水溶液萃取,萃取液过水相滤膜后直接进行LC-ESI MS/MS检测。选用Agilent Zorbax Eclipse XDB-C18色谱柱,以流动相0.1%(v/v)乙酸水溶液和0.1%（v/v）乙酸甲醇溶液梯度洗脱,质谱检测采用正离子扫描,多反应监测模式。NNN、NNK、NAT和NAB的检出限分别为0.019、0.002、0.008和0.007 μg/L,回收率为84.9%～104.5%,相对标准偏差(n=8)为2.96%～6.65%。该方法的检出限低,特异性好,适用于卷烟主流烟气中NNN、NNK、NAT和NAB释放量的检测。     

直接萃取-GC/MS法测定卷烟主流烟气中四种芳香胺

采用气相色谱/质谱法直接测定了卷烟主流烟气中的1-氨基萘、 2-氨基萘、 3-氨基联苯和4-氨基联苯等4种芳香胺.该方法直接用CH2Cl2溶剂超声振荡萃取滤片中的芳香胺,超声萃取的同时加入衍生试剂,使萃取和衍生化同步进行,萃取液过硅酸镁柱进行进一步纯化,然后旋转浓缩后进行GC/MS分析.方法的RSD在1.0%～3.7%之间,加标回收率在92.9%～101.1%之间.     

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.     

Analysis of cigarette smoke by laser desorption mass spectrometry

Laser desorption ionization Fourier transform ion cyclotron mass spectrometry (LDI–FTICRMS) has been successfully applied for the characterization of tobacco smokes. The versatily of analysis allows inorganic and organic tobacco smoke constituents to be identified. As a function of ion detection mode and laser irradiance experimental conditions, inorganic nitrate and sulfate as well as nicotine and associated nicotine, tobacco-specific nitrosamine, polycyclic aromatic hydrocarbon, polyoxygenated compounds are highlighted. The high mass resolution and the high mass accuracy attained by LDI–FTICRMS measurements allow the unambiguous assignment of detected species for m/z < 250 to be achieved.     

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.     

醋酸酐衍生-气相色谱-质谱联用测定葡萄酒中的糖醇

建立了先采用醋酸酐衍生然后用气相色谱-质谱联用仪检测葡萄酒中糖醇的方法。在葡萄酒中加入吡啶涡旋混合均匀,以5000 r/min (4℃)离心10 min。取上清液过有机滤膜,加入吡啶、醋酸酐衍生。加无水硫酸钠吸水后,经DB-5MS毛细管气相色谱柱分离,在选择离子监测(SIM)模式下进行检测。各目标物在0.019~1.25 mg/L (乳糖醇在0.039~2.50 mg/L)范围内线性关系良好,相关系数(r²)均大于0.99。赤藓糖醇、木糖醇、甘露糖醇、山梨糖醇、半乳糖醇和乳糖醇的定量限(信噪比(S/N)=10)分别为0.17、0.29、0.43、0.46、0.47和2.88 mg/L;检出限(S/N=3)分别为0.05、0.08、0.13、0.14、0.14和1.38 mg/L。在40 mg/L和80 mg/L加标水平下,6种糖醇在葡萄酒基质中的回收率为80.15%~108.75%,相对标准偏差(RSD)为2.16%~6.97%。该方法的灵敏度、准确度和精密度均符合相关的技术要求,适合于葡萄酒中糖醇含量的快速检测。     

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。     

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.     

Specific and sensitive determination of medroxyprogesterone acetate in human serum by gas chromatography-mass spectrometry

The mass fragmentographic determination of medroxyprogesterone acetate (MPA) in serum, using as internal standard medroxyprogesterone propionate (MPP) synthesized from MPA, is described. After addition of MPP, the sera are extracted on Sep-Pak C18 cartridges and MPA and MPP are detected as their respective 3-enol trifluoroacyl esters. Serum samples from 84 patients with breast cancer, daily receiving MPA orally, were determined showing a large variation in MPA concentrations (4-349 ng/ml). Our proposed gas chromatographic-mass spectrometric (GC-MS) method, which can be considered as a reference, was compared with a radioimmunoassay (RIA) method showing a correlation coefficient of 0.73 (n = 69; p much less than 0.001). The assay was also used to determine sequential serum levels of patients receiving a single oral dose of MPA. With only minor adjustments, the GC-MS method allows the determination of serum concentrations of related steroids such as megestrol acetate and cyproterone acetate.