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A method is described for the simultaneous analysis of hydrogen sulfide, carbonyl sulfide, methanethiol, carbon disulfide, methyl thiocyanate and methyl disulfide in mainstream vapor phase (MVP) cigarette smoke by gas chromatography–mass spectrometry. The fresh MVP smoke was collected in a gas bag, followed by injection of a 50 μL gas sample into the GC inlet via an automatic six-port valve. The separation was on a CP-PoraPLOT Q column and MS was operated in SIM mode. It was found that while carbonyl sulfide and carbon disulfide are very stable in the gas bag, hydrogen sulfide, methanethiol, methyl disulfide and methyl thiocyanate are extremely reactive and their levels increase or decrease drastically with the storage time in the gas bag. These results suggest that there is an absolute need to analyze the smoke sample as quickly as possible. Maintaining a precise time after the smoke collection is a key factor in order to obtain reproducible results. In this study, all the samples are injected within 2 min after MVP smoke was collected in the bag. Under smoke conditions of 60 mL puff of 2 s duration every 30 s, 12 brands of commercial cigarettes and Kentucky Reference 2R4F cigarettes were analyzed. Average values of three replicates of the 2R4F cigarettes were 31.6 μg cigt−1 hydrogen sulfide, 40.7 μg cigt−1 carbonyl sulfide, 25.6 μg cigt−1 methanethiol, 2.2 μg cigt−1 carbon disulfide, 23.7 μg cigt−1 methyl thiocyanate and 17.6 μg cigt−1 methyl disulfide. All other types of analyzed cigarettes show a similar quantitative distribution for these analytes.

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.

This paper presents a simple gas chromatography–mass spectrometry (GC–MS) technique for the analysis of vapor phase mainstream cigarette smoke. The analysis includes two parts: (A) separation and identification of as many as possible compounds in vapor phase smoke, and (B) quantitative analysis of a selected number of analytes. For achieving these objectives, the cigarettes are smoked using a Borgwaldt RM20/CS smoking machine using Federal Trade Commission (FTC), International Organization for Standardization (ISO), or other recommended conditions. The vapor phase smoke is separated from particulate phase smoke with a standard Cambridge pad. The vapor phase is collected in a gas bag, and then a precise volume (1 or 5 mL) is injected in a GC–MS system for separation and analysis. About 90 compounds are separated and identified in vapor phase smoke. A quantitative procedure was developed for acetaldehyde, 1,3-butadiene, acrolein, propionaldehyde, acetonitrile, acetone, isoprene, propionitrile, benzene, crotonaldehyde, hydrogen cyanide (HCN), and styrene. Using appropriate standards, most of the other compounds identified in vapor phase smoke could also be quantitated. Excellent reproducibility is obtained using this technique, the results being in good agreement with previously reported work. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 142–152, 2000

A selective, low temperature depolymerization procedure has been applied to four coals of different rank to obtain products that are representative of the original structural units (monoclusters) of the coal macromolecular component, and that are amenable to Chromatographic analysis. The monocluster products of this depolymerization procedure retain most of their original aromatic-hydroaromatic structures, whereas functional groups serving as intercluster linkages, e.g. alkylene and etheric groups, undergo predictable modification. A comparison of liquid 13C n.m.r. spectra of the products and solid state 13C n.m.r. spectra of the original coals showed only minor changes in the aromaticities between the solid and depolymerized products, but some loss of carbonyl carbons was detected in all of the coals. Both the tetrahydrofuran pre-extract and the depolymerized products of the four coals were separated into chemical classes by adsorption chromatography. Two of these fractions were found to consist predominantly of aliphatic hydrocarbons (paraffins and naphthenes) and alkylsubstituted bi-, tri- and (some) tetracyclic arenes. The fractions were analysed using gas chromatography-mass spectrometry. Structural identifications were based on a combination of Chromatographic retention and mass spectral fragmentation data. For the lower rank coals, the compositions of the pre-extracts were quite different from the corresponding depolymerized coal products, and contained various molecular biological markers. The compositions of the pre-extracts became closer to those of the depolymerized coal products as rank increased.

Wandoan Australian coal was extracted with benzene-ethanol and part of the residue was further extracted with pyridine at 350 °C. The n -hexane-soluble fractions of the two extracts have similar distributions of n -alkanes, methyl esters of straight-chain carboxylic acids and unidentified homologues C n H 2 n − 2 O 2 (or C n H 2 n O). This suggests that a large amount of extractable organic material is trapped in the coal matrix so tightly that it cannot be fully extracted using ordinary methods. Another part of the residue from the benzene-ethanol extraction was hydrogenated and the hexane-soluble part was separated into saturate, aromatic and polar fractions. The polar fraction was again hydrogenated in the same way. From the results of analysis it was concluded that paraffins in the hydrogenation product represented the reduction or decarboxylation products of straight-chain esters.

Wandoan Australian coal was separated into three parts by the float and sink method. The light(I) and medium(II) density fractions were extracted both by benzene-ethanol using ultrasonic irradiation and at 200 °C in an autoclave. The residue was hydrogenated in steps to obtain the n-hexane soluble part, raising the reaction temperature from 320 to 390 °C. The n-paraffins were analysed for each extract. Those from ambient extraction showed a bimodal distribution in the C12-C31 region with odd carbon numbers predominating in the C23-C31 region. In the case of the 200 °C extract a smooth distribution appeared at C12-C31. For the first hydrogenation, the paraffins were distributed at C12-C32 with a slight predominance of odd-paraffins in the C23-C31 region, and only one maximum at C26. When the temperature was increased from 320 to 390 °C the distribution approached two maxima at C12 and C26, with the former increasing in amount with the temperature. At the final stage there is a slight predominance of even paraffins in the region C14-C20 which is believed to originate from esters, acids, alcohols etc. It was also found that there was no serious difference between part I and II in the distribution of n-paraffins, but part I yielded greater amounts of saturated hydrocarbons than the corresponding part II.

Several series of alkyl aromatics with long chains were produced by catalytic thermal reactions (at 120–300 °C) between fatty acid or alcohol and phenol in the presence of activated clay. The compounds identified in the product are known to exist in coal e.g. in their solvent extracts, liquefaction products and pyrolysis products, etc., suggesting that similar reactions could occur during coalification. Reactions between fatty acid or alcohol and phenol include acylation, alkylations, cyclization, aromatization, dehydrogenation, dehydroxylation, dealkylation, and hydrogen transfer, which can be compared with those occurring in the coalification process. Thus, mild reactions between two abundant source materials from plants (phenols in lignin, and fatty acids or alcohols in lipids, wax, etc.) might be of geochemical significance in the genesis of many of the alkyl aromatics in contemporary coals.

Wandoan coal, after exhausting extraction by benzene/ethanol, has been liquefied by mild hydrogenation, and the hexane solubles were fractionated into saturate, aromatic and polar fractions. The polar fraction was vacuum distilled. The polar distillate was fully hydrogenated, dehydrogenated and separated to saturate (Fr. 31-1) and aromatic (Fr. 31-2) fractions. The non-distillable polar fraction was similarly hydrogenated and separated. All the aromatic fraction was dehydrogenated under 400 °C using palladium. The components in sub-fraction Fr. 31-2 were found to be similar to those of aromatics in other fractions, suggesting that aromatics in the hydrogenation product were probably derived from reduction of the polar fraction. The chemical structure of parent coal is composed mostly of polar compounds as found in the polar fraction.