scholarly journals Investigation of Non-Methane Hydrocarbons at a Central Adriatic Marine Site Mali Lošinj, Croatia

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 651
Author(s):  
Glenda Herjavić ◽  
Brunislav Matasović ◽  
Gregor Arh ◽  
Elvira Kovač-Andrić
Keyword(s):  
Volume Fraction ◽  
Ambient Air ◽  
Volatile Hydrocarbons ◽  
Po Valley ◽  
Flame Ionization ◽  
Volatile Organic ◽  
Marine Site ◽  
Positive Correlations ◽  
Potential Pollution ◽  
First Time

For the first time, volatile hydrocarbons were measured in Croatia, at Mali Lošinj in the period from autumn 2004 to autumn 2005. Mali Lošinj site is conveniently located as a gateway to Croatia for any potential pollution from either Po valley in Italy, or other locations in southern Europe or even Africa. The sampling was performed on multisorbent tubes and then analyzed by thermal desorption gas chromatography with a flame ionization detector. The aim was to determine and estimate the non-methane hydrocarbons in Mali Lošinj, a location with Mediterranean vegetation and species which emit large quantities of volatile organic compounds. Ozone volume fraction and meteorological parameters were also continuously measured, from April to October 2005. Ethane, ethene, ethyne, propane, propene, n-pentane, n-hexane, benzene and toluene were identified in all air samples. Benzene and toluene have been found in ambient air and significant positive correlations between ethyne and ethane, propane and propene indicate emissions from transport.

scholarly journals Optimization of a gas chromatographic unit for measuring biogenic volatile organic compounds in ambient air

2019 ◽  
Vol 12 (11) ◽  
pp. 6153-6171 ◽  
Author(s):  
Kenneth Mermet ◽  
Stéphane Sauvage ◽  
Sébastien Dusanter ◽  
Thérèse Salameh ◽  
Thierry Léonardis ◽  
...  
Keyword(s):  
Gaseous Mixture ◽  
Ambient Air ◽  
Internal Diameter ◽  
Flame Ionization ◽  
Volatile Organic ◽  
Chromatographic Unit ◽  
Gas Chromatographic Method ◽  
First Time ◽  
Calibration Step ◽  
Accurate Quantification

Abstract. A new online gas chromatographic method dedicated to biogenic volatile organic compound (BVOC) analysis was developed for the measurement of a 20 BVOC gaseous mixture (isoprene; β-pinene; α-pinene; limonene; ocimene; myrcene; sabinene; Δ3-carene; camphene; 1,8 cineole; terpinolene; linalool; α-phellandrene; nopinone; citral; α-terpinene; β-caryophyllene; p-cymene; γ-terpinene; and 2-carene) at a time resolution of 90 min. The optimized method includes an online Peltier-cooled thermodesorption system sample trap made of Carbopack B coupled to a gas chromatographic system equipped with a 60 m, 0.25 mm internal diameter (i.d.) BPX5 column. Eluent was analysed using flame ionization detection (FID). Potassium iodide was identified as the best ozone scrubber for the 20 BVOC mixture. In order to obtain an accurate quantification of BVOC concentrations, the development of a reliable standard mixture was also required. Quantification of BVOCs was reported with a detection limit ranging from 4 ppt for α-pinene to 19 ppt for sabinene. The main source of uncertainty was the calibration step, stressing the need for certified gaseous standards for a wider panel of BVOCs. This new method was applied for the first time to measure BVOCs in a pine forest during the LANDEX episode 1 field campaign (summer 2017). All target BVOCs were detected at least once during the campaign. The two major monoterpenes observed were β-pinene and α-pinene, representing 60 % of the measured terpenoid concentration on average, while isoprene represented only 17 %. The uncertainties determined were always below 13 % for the six major terpenes.

scholarly journals Optimization of a gas chromatographic unit for measuring BVOCs in ambient air

2019 ◽  
Author(s):  
Kenneth Mermet ◽  
Stéphane Sauvage ◽  
Sébastien Dusanter ◽  
Thérèse Salameh ◽  
Thierry Léonardis ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gaseous Mixture ◽  
Ambient Air ◽  
Flame Ionization ◽  
Volatile Organic ◽  
Chromatographic Unit ◽  
Gas Chromatographic Method ◽  
First Time ◽  
Calibration Step ◽  
Accurate Quantification

Abstract. A new online gas chromatographic method dedicated to Biogenic Volatile Organic Compounds (BVOC) analysis was developed for the measurement of a 20 BVOC gaseous mixture (isoprene, β-pinene, α-pinene, limonene, trans-β-ocimene, myrcene, sabinene, Δ3-carene, camphene, 1,8 cineole, terpinolene, linalool, α-phellandrene, nopinone, citral, α-terpinene, β-caryophhyllene, p-cymene, γ-terpinene and 2-carene) at a time resolution of 90 minutes. The optimized method includes an online Peltier-cooled thermodesorption system sample trap made of Carbopack B coupled to a gas chromatographic system equipped with a 60 m, 0.25 mm i.d. BPX5 column. Eluent was analysed using a flame ionization detection (FID). Potassium iodide was identified as the best ozone scrubber for the 20 BVOC mixture. In order to obtain an accurate quantification of BVOC concentrations, the development of a reliable standard mixture was also required. Quantification of BVOCs was reported with a detection limit ranging from 4 ppt for α-pinene to 19 ppt for sabinene. The main source of uncertainty was the calibration step, stressing the need of certified gaseous standards for a wider panel of BVOCs. This new method was applied for the first time to measure BVOCs in a pine forest during the LANDEX-episode-1 field campaign (summer 2017). All targeted BVOCs were detected at least once along the campaign. The two major monoterpenes observed were β-pinene and α-pinene, representing on average 60 % of the measured terpenoïds, while isoprene represented only 17 %. Uncertainties determined were always below 13 % for the six major terpenes. Uncertainties may be larger for the other compounds especially for those presenting a mixing ratio close to the detection limit.

scholarly journals Chemical Profile and Use of the Peat as an Adsorbent for Extraction of Volatile Compounds from Leaves of Geranium (Pelargonium graveolens L’ Herit)

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4923
Author(s):  
Edenilson dos Santos Niculau ◽  
Péricles Barreto Alves ◽  
Paulo Cesar de Lima Nogueira ◽  
Luciane Pimenta Cruz Romão ◽  
Graziele da Costa Cunha ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Extraction Method ◽  
Gas Chromatography Mass Spectrometry ◽  
Dynamic Headspace ◽  
Chemical Profile ◽  
Porapak Q ◽  
Pelargonium Graveolens ◽  
Flame Ionization ◽  
Volatile Organic ◽  
First Time

Volatile organic compounds (VOCs) from leaves of geranium (Pelargonium graveolens L’ Herit) were extracted by dynamic headspace using Porapak Q (HSD-P) as adsorbent and peat, a novel adsorbent in the extraction of plant volatiles, analyzed by gas chromatography–mass spectrometry (GC/MS) and gas chromatography–flame ionization (GC/FID), and the results were compared with those obtained by hydrodistillation (HD). The yield volatiles changed with the extraction method. HD was more efficient for extracting linalool (11.19%) and citronellyl formate (9.41%). Citronellol (28.06%), geraniol (38.26%) and 6,9-guaiadiene (9.55%) and geranyl tiglate (8.21%) were the major components identified by dynamic headspace using peat (HSD-T), while citronellol (16.88%), geraniol (13.63%), 6,9-guaiadiene (16.98%) and citronellyl formate (6.95%) were identified by dynamic headspace using Porapak Q (HSD-P). Furthermore, this work showed, for the first time, that in natura peat is useful to extract VOCs from leaves of geranium.

scholarly journals The Impact of Ambient Atmospheric Mineral-Dust Particles on the Calcification of Lungs

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Mariola Jabłońska ◽  
Janusz Janeczek ◽  
Beata Smieja-Król
Keyword(s):  
Mineral Dust ◽  
Smoking Habit ◽  
Lower Lobe ◽  
Ambient Air ◽  
Dust Particles ◽  
Masking Effect ◽  
Amorphous Calcium Carbonate ◽  
Calcium Salts ◽  
The Impact ◽  
First Time

For the first time, it is shown that inhaled ambient air-dust particles settled in the human lower respiratory tract induce lung calcification. Chemical and mineral compositions of pulmonary calcium precipitates in the lung right lower-lobe (RLL) tissues of 12 individuals who lived in the Upper Silesia conurbation in Poland and who had died from causes not related to a lung disorder were determined by transmission and scanning electron microscopy. Whereas calcium salts in lungs are usually reported as phosphates, calcium salts precipitated in the studied RLL tissue were almost exclusively carbonates, specifically Mg-calcite and calcite. These constituted 37% of the 1652 mineral particles examined. Mg-calcite predominated in the submicrometer size range, with a MgCO3 content up to 50 mol %. Magnesium plays a significant role in lung mineralization, a fact so far overlooked. The calcium phosphate (hydroxyapatite) content in the studied RLL tissue was negligible. The predominance of carbonates is explained by the increased CO2 fugacity in the RLL. Carbonates enveloped inhaled mineral-dust particles, including uranium-bearing oxides, quartz, aluminosilicates, and metal sulfides. Three possible pathways for the carbonates precipitation on the dust particles are postulated: (1) precipitation of amorphous calcium carbonate (ACC), followed by its transformation to calcite; (2) precipitation of Mg-ACC, followed by its transformation to Mg-calcite; (3) precipitation of Mg-free ACC, causing a localized relative enrichment in Mg ions and subsequent heterogeneous nucleation and crystal growth of Mg-calcite. The actual number of inhaled dust particles may be significantly greater than was observed because of the masking effect of the carbonate coatings. There is no simple correlation between smoking habit and lung calcification.

scholarly journals Allelopathic Effect of Serphidium kaschgaricum (Krasch.) Poljak. Volatiles on Selected Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 495
Author(s):  
Shixing Zhou ◽  
Toshmatov Zokir ◽  
Yu Mei ◽  
Lijing Lei ◽  
Kai Shi ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Volatile Oil ◽  
Amaranthus Retroflexus ◽  
Allelopathic Effect ◽  
Chemical Profile ◽  
Volatile Oils ◽  
Phytotoxic Activity ◽  
Volatile Organic ◽  
First Time ◽  
Stem Leaf

The chemical profile and allelopathic effect of the volatile organic compounds (VOCs) produced by a dominant shrub Serphidium kaschgaricum (Krasch.) Poljak. growing in northwestern China was investigated for the first time. Serphidium kaschgaricu was found to release volatile compounds into the surroundings to affect other plants’ growth, with its VOCs suppressing root elongation of Amaranthus retroflexus L. and Poa annua L. by 65.47% and 60.37% at 10 g/1.5 L treatment, respectively. Meanwhile, volatile oils produced by stems, leaves, flowers and flowering shoots exhibited phytotoxic activity against A. retroflexus and P. annua. At 0.5 mg/mL, stem, leaf and flower oils significantly reduced seedling growth of the receiver plants, and 1.5 mg/mL oils nearly completely prohibited seed germination of both species. GC/MS analysis revealed that among the total 37 identified compounds in the oils, 19 of them were common, with eucalyptol (43.00%, 36.66%, 19.52%, and 38.68% in stem, leaf, flower and flowering shoot oils, respectively) and camphor (21.55%, 24.91%, 21.64%, and 23.35%, respectively) consistently being the dominant constituents in all oils. Eucalyptol, camphor and their mixture exhibited much weaker phytotoxicity compared with the volatile oils, implying that less abundant compounds in the volatile oil might contribute significantly to the oils’ activity. Our results suggested that S. kaschgaricum was capable of synthesizing and releasing allelopathic volatile compounds into the surroundings to affect neighboring plants’ growth, which might improve its competitiveness thus facilitate the establishment of dominance.

scholarly journals Mechanochemical Synthesis and Nitrogenation of the Nd1.1Fe10CoTi Alloy for Permanent Magnet

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3854
Author(s):  
Hugo Martínez Sánchez ◽  
George Hadjipanayis ◽  
Germán Antonio Pérez Alcázar ◽  
Ligia Edith Zamora Alfonso ◽  
Juan Sebastián Trujillo Hernández
Keyword(s):  
Mechanochemical Synthesis ◽  
Applied Field ◽  
Volume Fraction ◽  
Synthesis Method ◽  
High Energy ◽  
Direction Parallel ◽  
Best Value ◽  
Heat Treated ◽  
Bcc Phase ◽  
First Time

In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd1.1Fe10CoTi compound from Nd2O3, Fe2O3, Co and TiO2. High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn12-type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N2. The magnetic properties Mr, µ0Hc, and (BH)max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were Mr = 75 Am2 kg–1, µ0Hc = 0.500 T and (BH)max = 58 kJ·m–3. Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH)max~114 kJ·m–3 was obtained for 3 h and the highest µ0Hc = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape.

scholarly journals Fast and Reliable Multiresidue Analysis of Aromas in Wine by Means of Gas Chromatography Coupled with Triple Quadrupole Mass Spectrometry

Analytica ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 38-49
Author(s):  
Ettore Guerriero ◽  
Massimo Iorizzo ◽  
Marina Cerasa ◽  
Ivan Notardonato ◽  
Bruno Testa ◽  
...  
Keyword(s):  
Direct Injection ◽  
Headspace Analysis ◽  
White Wine ◽  
Quadrupole Mass ◽  
Multiresidue Analysis ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
Steel Tank ◽  
First Time

The paper would like to show a direct injection into GC-MS/QqQ for the determination of secondary aromas in white wine samples fermented in two different ways. The procedure has been compared with more traditional methods used in this field, i.e., headspace analysis and liquid–liquid extraction. The application of such direct injection, for the first time in the literature, allows us to analyze Volatile Organic Compounds (VOCs) in the range 0.1–100 µg mL−1, with Limits of Detection (LODs) and Limits of Quantification (LOQs) between 0.01–0.05 µg mL−1 and 0.03–0.09 µg mL−1, respectively, intraday and interday below 5.6% and 8.5%, respectively, and recoveries above 92% at two different fortification levels. The procedure has been applied to real wine samples: it evidences how the fermentation in wood (cherry) barrel yields higher VOC levels than ones in wine fermented in steel tank, causing production of different secondary aromas and different relative flavors.

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