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Published in Leo M. L. Nollet, Dimitra A. Lambropoulou, Chromatographic Analysis of the Environment, 2017
Carolina Santamaría, David Elustondo, Esther Lasheras, Jesús Miguel Santamaría
Separation and analysis of BVOCs is usually carried out by GC, using conventional columns and identification and quantification is typically performed using mass-selective detectors (MSDs). The analysis of samples through using such configurations allows to discriminate between bark beetle-infested (higher concentrations of β-pinene, 3-carene, β-phellandrene, estragole, and p-cymene) or aphid-infected trees (higher concentrations of linalool, α-farnesene, and (E)-β-ocimene) from healthy trees from the identification of the individual BVOCs emitted by the different studied trees (Joó et al., 2010; Amin et al., 2012); to study the effect of global warming on the decrease in the water table of a boreal peat land from the increase in the concentration of monoterpene emissions under such conditions (Faubert et al., 2010); to identify the changes in BVOC emissions from different tree species with the time of the year (Hellén et al., 2012; Kim et al., 2013; Llusia et al., 2013); or to use BVOCs as tracers to distinguish between natural and anthropogenic sources in a volcanic area (Tassi et al., 2013).
Conifer Resins and Essential Oils: Chemical Composition and Applications
Published in Tatjana Stevanovic, Chemistry of Lignocellulosics: Current Trends, 2018
Nellie Francezon, Tatjana Stevanovic
Almost exclusively composed of hydrocarbon monoterpenes such as α-pinene, β-pinene, limonene, 3-carene, camphene (Fig. 5), turpentine oils possess the particularity of containing one major compound reaching up to 90% of their whole composition. This relative purity is advantageous in the perspective of isolating one targeted compound. For example, maritime pine Pinus pinaster and black pine Pinus nigra turpentines are composed of more than 90% of α-pinene (Mirov 1948). In the same range, Pinus strobus and Pinus edulis turpentine oils can contain up to 80% of α-pinene. Longleaf pine (Pinus palustris) or slash pine (Pinus caribaea) turpentines, the most produced essential oils in the United States during the XXI century, are mixtures of α- and β-pinenes up to 90% (Goldblatt 1952). Known as “American turpentines”, they were largely used in naval stores for the maintenance of wooden naval ships. Even if pinene isomers are widely represented in conifers and are most of the time the main components of turpentine oils, some pine species turpentines, such as Jeffrey pine (P. jeffreyi), gray pine (P. sabiniana) and Torrey pine (P. torreyana) are devoid of pinenes (Mirov 1948). Major compounds of Jeffrey pine and gray pine turpentines are not terpenes but heptane, a very flammable paraffin hydrocarbon naturally present in gasoline, which can reach up to 90% of their turpentine composition. In these particular cases of native western North American species, short-chain alkanes make up 95 to 99% of the turpentine composition. In the late XIX century, the discovery of heptane in Jeffrey pine turpentine was quite spectacular. The first batch processed in common distillation still destroyed the plant in a dramatic explosion (Mirov 1946).
Volatile organic compound and particulate emissions from the production and use of thermoplastic biocomposite 3D printing filaments
Published in Journal of Occupational and Environmental Hygiene, 2022
Antti Väisänen, Lauri Alonen, Sampsa Ylönen, Marko Hyttinen
The main VOC results are presented in Table 2 and all the detected compounds are listed in Supplementary Tables 2 and 3. The background concentrations for VOCs and carbonyls are presented in Supplementary Table 4. The same compounds were detected during filament extrusion and 3D printing processes, and the total VOC (TVOC) concentration ranges were 34–63 µg/m3 during filament extrusion and 41–56 µg/m3 during 3D printing. Lactide, commonly encountered in thermal processing of PLA, was the most abundantly detected compound (peak concentrations were 24 and 16 µg/m3 during filament extrusion and 3D printing, respectively), followed by various alcohols, acids, and aldehydes. The following terpenes were found in low concentrations: 3-carene, α-pinene, d-limonene, and p-cymene. Isoprene, the base unit of terpenes, was also detected. Cumulative terpene concentrations, including isoprene, ranged between 9 and 22 µg/m3, while the peak concentration of any single compound (3-carene and α-pinene) was only 8 µg/m3. The personal and stationary VOC results are indistinguishable as the operated machines were open and did not have any emission control mechanisms which resulted in free diffusion of the gaseous contaminants in the air. The concentrations of non-terpene VOCs were lower when wood or cellulose was present in the feedstock, but terpenes were introduced as new emission products. Hence, the TVOC levels were equal between the different feedstocks, but their VOC profiles were different. Terpenes contributed for 17–39% of TVOC during filament extrusion and 21–36% during 3D printing. The increase in wood content was associated with higher terpene portions of TVOC roughly equivalent for the wood or cellulose content, while no terpenes were encountered during processing of pure PLA. The TVOC ERs ranged between 2.6 and 3.6 × 102 µg/min during filament extrusion, and between 2.9 and 3.4 × 102 µg/min during 3D printing, and no consistent emission differences were found between the pure PLA and BC feedstocks.