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A domestic composite material based on silicon carbide and nitrile butadiene rubber was used to identify volatile substances of banana, banana flavor, and creamy chewing candies by passive adsorption in combination with thermal desorption GC–MS. This method can be used to determine a wide range of compounds, for example, esters of carboxylic acids, terpenoids, aldehydes, aromatic hydrocarbons, alkanes, heterocyclic compounds, phenols, glycerides, and fatty acids. The obtained chromatographic profiles of the samples were compared. In the chromatogram of "Banana" flavor, five peaks (out of eight) corresponded to the compounds that form the aroma of a banana, and in the chromatogram of "Love is" candies with banana flavor, three corresponding peaks (out of 21) were found. [ABSTRACT FROM AUTHOR]

This paper discusses the possibility of using a new graphene-based monolith material developed at the Department of Chemistry, Moscow State University, for the identification of new oil deposits or offshoots adjacent to already registered oil fields in the course of areal geochemical surveys. Sorption of volatile organic compounds (VOCs) from soil air within an oil field was performed using two sorbents (Tenax-TA traditionally used in such analytical tests and a carbon adsorbent) with subsequent gas chromatographic determination involving mass spectrometric detection and thermal desorption as a way of sample injection (TD/GC/MS). The new material absorbs more hydrocarbons (n-alkanes and monoaromatics) in the C8–C16 range than Tenax-TA, and its chromatographic peaks are more intense. The irreversible sorption phenomenon is observed for VOCs starting from C17 and higher; however, the concentrations of such substances in soil air are low owing to the low pressure of their saturated vapors under normal conditions. Overall, chromatograms obtained using the carbon monolith reflect the oilfield characteristics better compared to Tenax-TA. To enhance the sensitivity of determination, the thermal desorption conditions were optimized: the helium flow rate through the sorbent sample and the compound desorption time were adjusted to ensure the maximum peak area. The regeneration procedure was applied to the sorbent samples with the purpose of reusing them. Unlike the carbon monolith, Tenax-TA cannot be completely purified since it decomposes into its components at lower temperatures that the carbon monolith. Overall, the new graphene-based sorbent is not only reusable but also much cheaper than the imported polymer Tenax-TA since it is produced using only domestic materials. [ABSTRACT FROM AUTHOR]

Adsorbents used to analyze air for concentrations of various organic compounds with their subsequent determination by thermal desorption gas chromatography–mass spectrometry (GC–MS) are considered. Tenax-TA is the most commonly used material for such tasks, but it has drawbacks. The characteristics of adsorbents of Tenax, Carbosieve, Carboxen, Carbotrap, Capbopack, Porapak, Chromosorb families, XAD polymer resins, activated carbons, and some monolithic carbon materials are given. Their advantages and disadvantages for the adsorption/thermal desorption of hydrocarbons are discussed. The advantages of monolithic carbon materials and the need in the development of a new domestic material for analytical gas chromatography–thermal desorption mass spectrometry in solving oil-prospecting problems are substantiated. [ABSTRACT FROM AUTHOR]