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.     

Multi-element characterization of tobacco smoke condensate

In an interlaboratory study, 57 elements were assayed and 35 of them determined in cigarette smoke condensate of two different cigarette brands. The methods applied included inductively coupled plasma mass spectrometry, total reflection X-ray fluorescence analysis, instrumental neutron activation analysis and atomic absorption spectrometry. The main components carbon, hydrogen and nitrogen were determined by a CHN-combustion method. Sulphur was determined by a method based on the formation of hydrogen sulphide and precipitation micro-titrimetry. Considering the occurring concentrations and the toxicity, the most relevant elements in cigarette smoke condensate are arsenic, cadmium and lead which have relatively high transfer rates from tobacco into smoke.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

Determination of trace elements in total particulate matter of cigarette smoke by instrumental neutron activation analysis

Trace elements play an important role in the metabolism of the human body. Some of the trace elements are essential, whereas others are toxic and even carcinogenic. Cigarette smoke contains many of these hazardous trace elements. Tobacco samples have been analyzed by the authors for their trace element contents and the results have been reported earlier. This paper presents results on the trace element content analyzed in cigarette smoke using an automatic smoking machine developed in this laboratory to simulate actual smoking pattern. The trace element levels in the total particulate matter samples of the cigarette smoke collected on filter papers were measured and compared with those of cigarette smoke condensate reported in the literature. Both methods of collection give comparable results.     

High-pressure liquid chromatography of polynuclear aromatic hydrocarbons of cigarette smoke condensate

Reverse-phase, high-pressure liquid chromatography (h.p.l.c.) on Permaphase ODS and ETH was applied to the fractions of cigarette smoke condensate containing polynuclear aromatic hydrocarbons (PAH). A PAH-enriched fraction was first separated by gel filtration, and selected fractions were subjected to h.p.l.c. Although standard PAH could be easily separated on Permaphase ODS, results with smoke condensate were unsatisfactory. Better results were obtained with Permaphase ETH, which gave sufficient resolution for identification. PAH identification was aided by means of a stop-flow technique and measurement of the u.v. spectra of eluting peaks. Benzo(a)pyrene in the smoke condensate could be determined. However, for resolution of the PAH in smoke condensates, the total overall performance of h.p.l.c. was judged inferior to that of gas chromatography.     

Isolation of polyaromatic hydrocarbons from whole smoke condensate: A simple two-step procedure

Summary A simple two-step procedure for isolating polyaromatic hydrocarbons from whole smoke condensate has been devised. Preliminary separation of a blue fluorescent zone from whole smoke condensate by preparative thin-layer chromatography yields a crude polyaromatic hydrocarbon fraction. A highly enriched polyaromatic hydrocarbon fraction is obtained by passage through a short Sephadex LH-20/isopropanol column. The isolation procedure and a temperature-programmed gas chromatographic scan can be run in less than eight hours.     

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.     

Simultaneous determination of amino-alpha-carbolines and amino-gamma-carbolines in cigarette smoke condensate by high-performance liquid chromatography

A method for the simultaneous detection of amino-alpha-carbolines (2-amino-alpha-carboline and 2-amino-3-methyl-alpha-carboline) and amino-gamma-carbolines (3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole and 3-amino-1-methyl-5H-pyrido [4,3-b]indole) by high-performance liquid chromatography has been developed. It consists of a three-step purification using three different columns with fluorometric detection. With this method, we have demonstrated that both amino-alpha-carbolines and amino-gamma-carbolines are present in cigarette smoke condensate. The method may be useful for detecting these carcinogens in various materials.     

Collection and preparation of sidestream cigarette smoke for trace elemental determinations by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

A novel method for the collection and preparation of sidestream cigarette smoke condensate is described for trace elemental analysis by inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry. The smoke collection method utilizes a specially designed chimney that collects and directs the sidestream smoke (SS) to a 2-stage trapping system consisting of an impaction trap followed by a 0.8 microm mixed cellulose ester filter. The samples are digested with nitric acid in a commercial heating block before analysis. The method limits of detection (LODs) are 1, 0.2, 2, 9, 6, and 7 ng/cigt for As, Cd, Pb, Ni, Se, and Cr, respectively. The SS collected from an industry reference cigarette, 1R4F, produced by the University of Kentucky was analyzed. The concentrations of As, Cd, and Pb in 1R4F were determined to be 27.3+/-2.1, 412+/-14, and 43.8+/-2.0 ng/cigt, respectively, while the concentrations of Ni, Cr, and Se are below the method LOD. Consequently, this novel method successfully addresses contamination, instrumentation, and collection issues for performing trace elemental analysis of sidestream cigarette smoke condensate.     

Determination of Cd levels in smoke condensate of Brazilian and Paraguayan cigarettes by Thermospray Flame Furnace Atomic Absorption Spectrometry (TS-FF-AAS)

In this study, the concentrations of Cd in smoke condensate of Paraguayan and Brazilian full flavor normal size cigarettes were determined. A “fishtail” chimney was used to confine and direct cigarette smoke to an impaction trap followed by 3 MCE (mixed cellulose ester) filters for smoke collection. The smoke condensate collected at the first two collection stages (chimney and impactor) was prepared as Triton X-100 slurry samples and the 3 MCE filters (third collection stage) used to collect smoke were microwave digested. Samples were analyzed by Thermospray Flame Furnace Atomic Absorption Spectrometry (TS-FF-AAS) for Cd and the results obtained were compared with Graphite Furnace Atomic Absorption Spectrometry (GFAAS). No significant differences were found between the values obtained with TS-FF-AAS and GFAAS at a 95% confidence level. The total concentration of Cd in the smoke of Brazilian and Paraguayan cigarettes tested ranged from 187 to 281 ng/cigarette and from 176 to 271 ng/cigarette, respectively. The LODs for Cd using TS-FF-AAS and GFAAS, were 5.8 and 1.5 ng/cigarette, respectively, for the analysis of smoke condensate from 1 cigarette. The main advantages of using the simple TS-FF-AAS system are its low running costs and the analysis time when compared to GFAAS.     

Analytical study of cigarette smoke enriched in benzo[a]pyrene for use in model animal studies

Cigarette smoke has been significantly enriched in benzo[a]pyrene (BAP) by injecting 200 μl of a cyclohexane solution, containing a total of 40 μg of BAP, into a cigarette. After injection, the cigarette is conditioned and smoked according to standard protocol. When the cigarette smoke condensate is analyzed by fluorescence spectroscopy, liquid scintillation counting, gas chromatography with flame ionization detection, and gas chromatography-mass spectrometry, it is found that the level of BAP has increased by 1000 times with respect to levels reported for unenriched cigarette smoke. No chemical transformation of the BAP has been detected, and the BAP-enriched fraction does not appear to be perturbed to a detectable degree. Approximately 28% of the BAP is measured in the mainstream smoke, 46–48% in the sidestream smoke from the burning end of the cigarette, and 7% in the butt and ash. Correcting for analytical losses, about 10% appears to escape in the gaseous state. This material may prove suitable for model animal studies.     

Separation and quantitation of monovalent anionic and cationic species in mainstream cigarette smoke aerosols by high-performance ion chromatography

A simple method has been developed to separate and quantitate monovalent ionic species in mainstream cigarette smoke aerosols based on ion chromatography (IC) with conductivity detection. The method entails collecting the smoke aerosol particulate phase by electrostatic precipitation, dissolving the smoke condensate in methanol (MeOH), and separating the ionic species on either a cation- or anion-exchange column. The method has been applied to the analysis of smoke aerosols from two cigarettes, 1R4F Kentucky Reference cigarettes and a new cigarette that heats but does not burn tobacco. The predominant cations in smoke aerosols from 1R4F Kentucky Reference and the new cigarettes are sodium (Na+), ammonium (NH4+), and potassium (K+) ions; the predominant anions are acetate (AcO-) and formate (HCOO-). Trace amounts of chloride (Cl-), nitrite (NO2-), and nitrate (NO3-) ions are also present.     

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.     

Two new alkaloids from cigarette smoke condensate

Chemical constituents of MeOH extracts of cigarette smoke were studied. Two new alkaloids, named cigatin A (1), 2-(Pyridine-3-yloxy)-benzene-1',4'-diol and B (2), 2-(4-Methyl-pyridin-3-yloxy)-benzene-1',4'-diol, were isolated from a mainstream condensate of cigarette together with seven known alkaloids. Their structures were determined on the basis of spectral data and chemical methods.     

Flame retardance and smoke suppression by tin(IV) oxide phases and decabromobiphenyl

Flame retardance and smoke suppression have been studied in three systems containing acrylonitrile-butadiene-styrene terpolymer, decabromobiphenyl, and (a) commercial metastannic acid, (b) laboratory-prepared metastannic acid and (c) anhydrous tin(IV) oxide. Values of limiting oxygen index and smoke density have been measured for a large number of compositions in each system. They have then been fitted by fourth-order polynomials and plotted in triangular diagrams. Optimum atomic ratios for all these synergistic systems were found to be: Br/Sn = 9, a value which is much higher than would be expected from stoichiometric calculations. The systems also possess significant smoke-suppressant effectiveness.     

Gel permeation chromatography of oxygenated components of cigarette smoke condensate

Oxygenated neutral constituents of a tumor-inhibiting fraction of cigarette smoke condensate were separated from interfering phenolic compounds by a combination of silicic acid and gel chromatography. Silicic acid adsorption and Bio-Beads gel chromatography separated aliphatic from aromatic ketones, and gel chromatography on Sephadex LH-20 resolved aromatic ketones from phenols. Identifications were achieved by studying individual fractions by g.c. and g.c.—m.s.     

Characterization of cigarette smoke condensates by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC x GC/TOFMS). Part 2: basic fraction

Cigarette smoke condensate is a complex chemical matrix. Analysis of nitrogen-containing compounds present therein is very difficult because of the limitation of the peak capacity of conventional one-dimensional chromatography. Extensive and laborious sample preparation is frequently required or selective detectors are frequently used. In this study, the basic fraction of mainstream cigarette smoke condensate has been investigated by using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC x GC/TOFMS). Auto data processing by TOFMS software combined with manual identification was used to assign the components. 377 nitrogen-containing compounds, including 155 pyridine derivatives, 104 quinoline/isoquinoine derivatives, and 56 pyrazine derivatives were tentatively identified. By selecting appropriate unique masses and in the light of the component positions in the structured chromatogram, alkyl-substituted pyridines, pyrazines, and quinolines/isoquinolines were separately shown and further validated. The peaks of eight individual positional isomers of two-carbon-substituted pyridines and thirteen positional isomers of methyl-substituted quinolines/isoquinolines were further confirmed, based on linear incremental retention behavior in combination with TOFMS and the structured chromatogram of GC x GC.     

Development of an improved method for the determination of polycyclic aromatic hydrocarbons in mainstream tobacco smoke

A gas chromatograph/mass-selective detection (GC/MS) method has been developed and validated for the quantitation of 16 polycyclic aromatic hydrocarbons found in mainstream tobacco smoke condensate. The utilization of two types of solid-phase extraction media combined with capillary column technology removed matrix interferences, afforded a significant reduction in analysis run time, and increased accuracy. Also, the addition of a chilled impinger was used to trap semi-volatile polycyclic aromatic hydrocarbons and to provide more accurate data. This was done without sacrificing the repeatability, reproducibility, and precision obtained in previously published methods. The development and validation studies discussed in this paper resulted in an improved, robust analytical method capable of increasing laboratory capacity and reducing sample reporting time.     

Isolation and identification of two new seco-cembranoids from cigarette smoke

The isolation and identification from cigarette smoke condensate of 5-isopropyl-8,12-dimethyl-3$\text{E}$,8$\text{E}$,12$\text{E}$,l4-pentadecatetraen-2-one and its 12$\text{Z}$ isomer are reported.     

Determination of benzo[a]pyrene in cigarette smoke condensate by liquid chromatography on amberlite xad-2

A method is described for the determination of benzo[a]pyrene in cigarette smoke condensate which utilizes chromatographic fractionation on Amberlite XAD-2. PAH are initially separated by step-wise gradient elution, progressing from reverse to normal-phase modes of operation. Other separation steps involve automated column chromatography on silica gel and thin-layer chromatography on 20% acetylated cellulose. Benzo[a]pyrene is finally determined by u.v. spectrophotometry and liquid scintillation counting of ¹⁴C—benzo[a]pyrene tracer. Results obtained compare favorably with those of the more traditional liquid—liquid extraction methods.