Chemical Studies on Tobacco Smoke. XLVII. On the Quantitative Analysis of Catechols and Their Reduction

Abstract

A quantitative analytical method has been developed for catechols in tobacco smoke using catechol-¹⁴C as internal standard. Main and sidestream smoke particulates are collected in cold traps, the acidic portion of the particulate matter is neutralized and the catechols are enriched by complexing with boric acid. The concentrate of the dihydroxybenzenes is analyzed by GLC/MS.     

A feasibility study on oxidation state of arsenic in cut tobacco,mainstream cigarette smoke and cigarette ash by X-ray absorption spectroscopy

This work describes the application of synchrotron-based X-ray Absorption Near-Edge Structure spectroscopy to study the oxidation state of arsenic in cigarette mainstream smoke, cut tobacco and cigarette ash. The level of arsenic in the total particulate matter of the smoke is approximately 1 ppm for the standard research reference cigarette 2R4F and its replacement 3R4F. Smoke particulate samples collected by a conventional glass-fiber membrane (commercially known as Cambridge filter pad) and a jet-impaction method were analyzed and compared. In addition smoke particulate samples were aged either at ambient temperature or at 195 K. X-ray Absorption Near-Edge Structure spectroscopy results revealed that the cut tobacco powder and cigarette ash contained almost exclusively As^V. The smoke particulate samples however contained a mixture of As^III and As^V. The As^V in the smoke particulate was reduced to As^III upon aging. Stabilizing the smoke particulate matter at 195 K by solid CO₂ slowed down this aging reaction and revealed a higher percentage of As^V. This behavior is consistent with the redox properties of the arsenic species and the smoke particulate matrix.     

Chemical Studies on Tobacco Smoke. LXI. Volatile Pyridines: Quantitative Analysis in Mainstream and Sidestream Smoke of Cigarettes and Cigars

Abstract

A quantitative analytical method has been developed for volatile pyridines in tobacco smoke using pyridine- ¹⁴C as an internal standard. Mainstream and sidestream smoke are trapped in 0.05 N sulfuric acid anti partitioned with chloroform. The acidic portion is then concentrated, adjusted to pH 3 and extracted with chloroform. Methanol and a trace of 2N sulfuric acid are added to this chloroform portion and the mixture is carefully concentrated.

A trace of sodium hydroxide is added and the final concentrate is analyzed by gas chromatography. Twenty-one volatile pyridines have been identified. The mainstream stroke of a popular. 85-mm U.S. cigarette without filter tip contained the following major pyridines: 33.4 μg pyridine, 12.3 μg α-picoline, 24.2 μg. β+γ-picoline, 7.6 μg 3-ethylpgridine, 5.9 μg: 4-ethylpyridine, and 23.3 μg 3,4-lutidine + 3-vinylpyridine. The sidestream smoke of this cigarette contained up to 28 times higher concentrations of pyridines.

Volatile pyridines were also determined in the mainstream smoke of other non-filter cigarettes, filter cigarettes, little cigars and, a non-tobacco cigarette. Of special interest were the much greater quantities of volatile pyridines in the mainstream and sidestream of cigars in comparison to those of cigarettes. The ratio of pyridines in sidestream to those in mainstream was 5 to 50 in large cigars. Selective filtration was observed with both cellulose acetate and charcoal filter tips. The analytical method resulted in reproducible values for pyridine, with an average recovery rate of more than 90%. In addition to pyridines, two pyrazines were also isolated from the smoke. Processed tobacco contained minute amounts of some volatile pyridines.     

Reactions of Dicyclopentadienyltitanium(III) compounds with carbon monoxide

Reactions of Cp₂TiR (R = Cl, C₆F₅, C₆H₅, o-CH₃C₆H₄) with CO give two types of products: terminally coordinated adducts, Cp₂Ti(R)CO, and insertion products, Cp₂TiCOR, i.e. acyl compounds. The acyl ligand is η²-coordinated at the titanium atom. The preparations and properties of the compounds are described.     

N-Monobromamide: Darstellung durch Bromierung mit „Dibromisocyanursäure”, Eigenschaften

By reaction of primary carboxamides with “dibromoisocyanuric acid” (DBI) N-monobromoamides can be readily obtained as well as the N,N-dibromoamides described in an earlier paper¹. Reactions, some of them new, and properties of these compounds are described and compared with those of the N,N-dibromoamides. Like other compounds bearing the NHBr group^{2, 3} the N-monobromocarboxamides disproportionate at room temperature according to: 2 RCONHBr ? ? RCONH₂+RCONBr₂. For CH₃CONHBr the equilibrium constant was found to beK=0.02. In aqueous solution they behave as weak acids. The dissociation constants of eight compounds [R=?CH₃, ?C₂H₅, ?CH₂Cl, ?CHCl₂, ?CCl₃, ?CF₃, ?C(CH₃)₃ and ?C₆H₅] were measured: they differ from those of the corresponding carboxylic acids by about three powers of ten.     

Synthesis and properties of aryldicyclopentadienyltitanium(III) compounds

The synthesis and properties of the compounds Cp₂TiR, with R = C₆H₅, o-, m-, p-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃, 2,4,6-(CH₃)₃C₆H₂, C₆F₅, CH₂C₆H₅, are described. Chemical and physical properties indicate that the R groups are σ-bonded to the titanium atom. The complexes are monomeric, with one unpaired electron per titanium atom. They are very air sensitive, and vary markedly in thermal stability; some of the compounds react with molecular nitrogen, to give complexes of the general formula (Cp₂TiR)₂N₂. Compounds CP₂TiR with R = alkyl could not be isolated.     

Study on the effect of potassium lactate additive on the combustion behavior and mainstream smoke of cigarettes

The influence of potassium lactate (PL) on the combustion behavior and semi-volatile compounds of tobacco during smoking is investigated in this study. The addition of PL showed no effect on the content of total particulate matter, nicotine-free dry particulate matter, puff number, and nicotine. Meanwhile, a 22.5 % increase in moisture content and 3 % decrease in CO content of mainstream smoke were observed when the added amount of PL was up to 2 %. The differential thermogravimetric curves indicated that PL decreased the maximum combustion rate and influenced the thermal degradation stage of tobacco by shifting the peak point of temperature to a higher value. The gas evolution profiles obtained from Fourier transform infrared spectroscopy during combustion showed that PL could lower the CO and CO₂ yield, but did not affect the generation of CH₄ and carbonyl compounds. A great variation in semi-volatile components of the mainstream smoke was also observed from the tobacco containing PL compared with the control. The comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry analysis showed that PL increased the yield of alcohols, lactons, miscellaneous oxygenated compounds and amides, but decreased that of aldehydes, acids, pyrroles and pyrazines. A small added amount (0.2 %) of PL reduced the content of total semi-volatile substances, ketones, esters, phenols, hydrocarbons, pyridines, tobacco alkaloids, and nitrogenous compound. However, the contents of these substances were not affected when the added amount was >0.2 %. PL bound the ash during combustion, thereby leading to the change of combustion behavior and certain smoke components.     

Determination of Polycyclic Aromatic Hydrocarbons in Tobacco Smoke by Ionic Liquid Enrichment and Gas Chromatography – Mass Spectrometry

A rapid, efficient and environmentally friendly method based on the ionic liquid (IL) 1-hexyl-3-methylimidazolium hexafluorophosphate ([C₆MIM][PF₆]) was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in mainstream tobacco smoke. This technique combined ionic liquid (IL) enrichment with solvent reverse extraction for the replacement of solid phase extraction and rotary evaporation in the traditional method and enriched PAHs in the organic solvent. Several parameters, including the type of ionic liquid, volume of ionic liquid and water, extraction time, vortex time and reverse extraction time, were optimized. After pretreatment, the analytes were analyzed by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM). Satisfactory results were achieved when this method was applied to determine PAHs in mainstream tobacco smoke. The calibration curves were linear with correlation coefficients ranging from 0.9955 to 0.9999 at concentration levels of 10–800?µg?L^?1, and the relative standard deviations of the optimized method were between 0.7% and 5.3%. The limits of detection were 0.01–0.6?ng cig^?1, and the recoveries of the compounds were 80.2–118%. A comparison of this protocol with literature methods demonstrated that the proposed procedure provides accurate and reliable sample-treatment for the determination of PAHs in tobacco samples.     

Thermogravimetric analysis of inclusion compounds of perhydrotriphenylene with highern-alcohols

The vaporization of perhydrotriphenylene and its inclusion compounds with higher evennumberedn-alcohols from C₈ to C₁₆ has been studied using thermogravimetric analysis. For the inclusion compounds of perhydrotriphenylene with the C₈, C₁₀ and C₁₂ n-alcohols, kinetic analysis shows that the vaporization processes of then-alcohol and the perhydrotriphenylene are partially superimposed, while for the inclusion compound perhydrotriphenylene-hexadecanol-1, the above processes are totally superimposed. From the experimental kinetic parameters the values of the preexponential factors corresponding to the vaporization of then-alcohols and perhydrotriphenylene were calculated, as were the compositions of the inclusion compounds of perhydrotriphenylene with the C₈-C₁₂ n-alcohols.     

Investigation of structural states in the series MGaSiO4, MAlGeO4, MGaGeO4 (M = Na,K)

MGaSiO₄, MAlGeO₄, and MGaGeO₄ phases (M = Na, K) have been synthesized using flux, hydrothermal, and melt growth techniques and characterized by TEM and single crystal and powder X-ray diffraction. The K compounds crystallize with a (2√3A, C) hexagonal unit cell which is a superstructure of the (A, C) hexagonal kalsilite (KAlSiO₄) cell. The room-temperature polymorphs of the Na compounds crystallize with a (√3A, 3A, C, γ ⋍ 90°) monoclinic cell and are isostructural with beryllonite (NaBePO₄). TEM data suggest that they transform to a kalsilite-like (√3A, C) hexagonal cell at high temperature.     

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.     

Synthesis of trifluorovinylpolyhaloaryl compounds via polyhaloarylcopper complexes

The synthesis of some polyhaloarylcopper complexes (Ar_xCu; Ar_x = C₆F₅, p-HC₆F₄, p-BrC₆F₄, C₅NF₄, C₅NCl₄ and C₆Cl₅) and their reactions with F₂C = CFI to yield the F₂C=CFAr_x compounds are described. The copper coupling reaction between C₆F₅I and F₂C=CFI as an alternate procedure for preparation of F₂C=CFAr_x has also been studied.     

The identification of aliphatic amines in air as their benzamides by paper chromatography

A method is described for the separation of amines as their benzamides by paper chromatography. Data are given on separations in two systems. Homologous benzamides from C₁ to C₁₀ are best separated on S & S ₂₀₄₅a paper while C₁₀ and C₁₂ are separated on 2045a paper. When radio-carbon labelled benzamides were chromatographed and placed on x-ray film for eight to ten days with subsequent development of the radioautograph, the lower limit of identification was found to be ca. 2.5 μg of each benzamide. The results of analysis for amines in two samples of air particulate matter, and one of atmospheric vapors are presented.     

Cationic rhodium tetrafluorobenzobarrelene complexes with diolefin or arene ligands,crystal structures of [Rh(TFB)(arene)] ClO4, (arene = C6Me6, C6H3Me3, C6H4Me2)

The preparation and properties of complexes of the general formulae [Rh(TFB)(diolefin)]ClO₄, [Rh(TFB)(arene)]ClO₄ and [Rh(TFB)L₂]ClO₄, (TFB = tetrafluorobenzobarrelene, L = dimethylsulfoxide and tetrahydrothiophen) are described. The crystal structures of the arene complexes (arene = C₆Me₆, C₆H₃Me₃ and C₆H₄Me₂) have been solved by X-ray methods. The three compounds crystallize in quite similar lattices: R3c, a = b = 27.122, 26.233, 25.731 and c = 17.079, 16.388, 16.256 Å, respectively. δR-plots for about 2000 reflections show the agreement in the refinements carried out up to R-values of 5%, 5% and 4% respectively. The Rh atom is coordinated to the double bonds of the TFB and to the arene ring in all three compounds, but the deviation from planarity of the arene and its relative position with respect to the TFB moiety varies.     

(p, ϱ, T) for {(1−x)C6H6 + xC6D6} and {(1−x)C6H6 + xC6F6} in the range 298 to 373 K and 0.1 to 400 MPa

The behaviour of (p, ?, T) for C₆H₆, C₆F₆, and five mixtures, and of C₆D₆ and (0.5C₆H₆ + 0.5C₆D₆) has been determined at 298.2, 323.2, 348.2, and 373.2 K, and from 0.1 MPa, or saturation pressure, to the point of onset of solidification or to 400 MPa. The experimental results are tabulated and the isothermal densities are represented by a polynomial equation for the secant bulk modulus in terms of the pressure. The temperature and pressure dependence of the molar excess volume is described.     

Components of the Lauraceae family—I : New lactonic compounds from Litsea japoncia

Six new compounds, named litsenolides A₁, A₂, B₁, B₂, C₁ and C₂, have been isolated from the roots of Litsea japonica (Japanese name “Hamabiward). Spectral and chemical evidence shows that these six compounds are three pairs of β-hydroxy-γ-methyl-αβ′-unsaturated-γ-lactones having a long carbon chain terminated with a methyl (C series), an allyl (A series) or a propargyl (B series) group. The two components of each pair differ only in the structure, cis or trans, at the double bond conjugated with the lactone group. The absolute stereochemistry of the compounds is also discussed.     

The extended chain compounds Ln12(C2)3I17 (Ln=Pr, Nd, Gd, Dy): Synthesis, structure and physical properties

The title compounds are obtained in high yield from stoichiometric mixtures of Ln, LnI₃ and graphite, heated at 900-950 °C in welded Ta containers. The crystal structures of new Pr and Nd phases determined by single-crystal X-ray diffraction are related to those of other Ln₁₂(C₂)₃I₁₇-type compounds (C 2/c, a=19.610(1) and 19.574(4) Å, b=12.406(2) and 12.393(3) Å, c=19.062(5) and 19.003(5) Å, β=90.45(3)° and 90.41(3)°, for Pr₁₂(C₂)₃I₁₇ and Nd₁₂(C₂)₃I₁₇, respectively). All compounds contain infinite zigzag chains of C₂-centered metal atom octahedra condensed by edge-sharing into the [tcc]_∞ sequence (c=cis, t=trans) and surrounded by edge-bridging iodine atoms as well as by apical iodine atoms that bridge between chains. The polycrystalline Gd₁₂(C₂)₃I₁₇ sample exhibits semiconducting thermal behavior which is consistent with an ionic formulation (Ln³⁺)₁₂(C₂^6-)₃(I⁻)₁₇(e⁻) under the assumption that one extra electron is localized in metal-metal bonding. The magnetization measurements on Nd₁₂(C₂)₃I₁₇, Gd₁₂(C₂)₃I₁₇ and Dy₁₂(C₂)₃I₁₇ indicate the coexistence of competing magnetic interactions leading to spin freezing at T_f=5 K for the Gd phase. The Nd and Dy compounds order antiferromagnetically at T_N=25 and 29 K, respectively. For Dy₁₂(C₂)₃I₁₇, a metamagnetic transition is observed at a critical magnetic field H≈25 kOe.     

Synthesis of 13C4-labelled oxidized metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene

Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BaP), are ubiquitous environmental contaminants that are implicated in causing lung cancer. BaP is a component of tobacco smoke that is transformed enzymatically to active forms that interact with DNA. We reported previously development of a sensitive stable isotope dilution LC/MS method for analysis of BaP metabolites. We now report efficient syntheses of ¹³C₄-BaP and the complete set of its ¹³C₄-labelled oxidized metabolites needed as internal standards They include the metabolites not involved in carcinogenesis (Group A) and the metabolites implicated in initiation of cancer (Group B). The synthetic approach is novel, entailing use of Pd-catalyzed Suzuki, Sonogashira, and Hartwig cross-coupling reactions combined with PtCl₂-catalyzed cyclization of acetylenic compounds. This synthetic method requires fewer steps, employs milder conditions, and product isolation is simpler than conventional methods of PAH synthesis. The syntheses of ¹³C₄-BaP and ¹³C₄-BaP-8-ol each require only four steps, and the ¹³C-atoms are all introduced in a single step. ¹³C₄-BaP-8-ol serves as the synthetic precursor of all the oxidized metabolites of ¹³C-BaP implicated in initiation of cancer. The isotopic purities of the synthetic ¹³C₄-BaP metabolites were estimated to be ≥99.9%.     

The Distribution of Total Particulate Matter (TPM) And Nicotine Between Mainstream and Sidestream Smoke in Bidis and Cigarettes

ABSTRACT

The mainstream (MS) and sidestream (SS) smoke of three types of popular Indian cigarettes, a brand of low tar Indian cigarettes, a brand of US cigarettes and two brands of popular Indian bidis were analysed for carcinogenic total particulate matter (TPM) and nicotine levels employing standard smoking conditions and/or modified smoking standards.

The analysis clearly demonstrated relatively higher levels of TPM and nicotine in MS of three types of popular Indian cigarettes when compared with a brand of low tar Indian cigarettes or a brand of US cigarettes or reported values for MS of western cigarettes. This was also reflected in MS/SS ratios of TPM and nicotine as TPM and nicotine levels in SS of Indian and US cigarettes were similar, when tested employing standard smoking conditions.

Comparative analysis of Indian bidis/cigarettes and a brand of US cigarettes employing modified smoking standard (i.e. 2 puffs/min instead of 1 puff/min) revealed significantly lower values of TPM and nicotine in SS of Indian bidis when compared with corresponding values in Indian/US cigarettes. This shows that contribution of TPM and nicotine in SS from a single bidi to environmental tobacco smoke (ETS) is very much less than that of a single cigarette, and contribution of SS from Indian and US cigarettes to ETS appear to be similar. Reduced levels of TPM and nicotine in SS of bidis, probably due to lack of added burning agents, result into relatively higher deliveries of TPM and nicotine in MS as reflected by higher MS/SS values.     

CaMnO2.5 and Ca2MnO3.5: New oxygen-defect perovskite-type oxides

We found that when the precursors CaMnO₃ and Ca₂MnO₄ are reduced with any one of a variety of inorganic (H₂, NH₃) or organic (C₂H₄, C₃H₆) reducing agents between 300 and 500°C, topotactic reaction occurs to produce the ordered oxygen-defect phases CaMnO_2.5 and Ca₂MnO_3.5, respectively. Orthorhombic cell constants for CaMnO_2.5 are a = 5.43(1), b = 10.24(1), and c = 3.74(1) Å, and for Ca₂MnO_3.5 are a = 5.30(1), b = 10.05(1), and c = 12.24(1)Å. These compounds were characterized by powder X-ray diffraction, thermogravimetric analysis, magnetic susceptibility, and infrared spectroscopy. The reduced compounds reversibly oxidize to their respective precursor in oxygen at low temperatures.