scholarly journals Exposure Studies of Different Kinds of Volatile Organic Compounds in Vapour Phase with a Narrow-gap Cell Containing CuxS Modified Carbon Microdisc Electrode

2018 ◽  
Vol 63 (1) ◽  
pp. 170-178 ◽  
Author(s):  
László Kiss
Keyword(s):  
Acetic Acid ◽  
Volatile Organic Compounds ◽  
Ethyl Acetate ◽  
Organic Compounds ◽  
Modified Electrode ◽  
Vapour Phase ◽  
Narrow Gap ◽  
Current Increase ◽  
Interelectrode Gap ◽  
Volatile Organic

In this article, the feasibility of the CuxS modified carbon microdisc electrode was examined by exposure to four different volatile organic compounds (2-propanol, acetic acid, ethyl acetate and n-butylamine) directly in their vapour phase using cyclic voltammetry and amperometry. The performance of the modified microdisc was compared with the bare carbon microdisc (30 μm in diameter) which was involved in a narrow-gap cell. By using both methods high current increase was observed for 2-propanol with the modified electrode and its sensitivity was sufficiently higher than with the bare electrode. The modified electrode showed lower current signals in case of acetic acid and n-butylamine. The latter formed a condensation layer at the interelectrode gap. Neither the bare nor the modified electrode was sensitive to ethyl acetate.

scholarly journals Plant Growth Regulators Improve the Production of Volatile Organic Compounds in Two Rose Varieties

Plants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 35 ◽  
Author(s):  
Mohammed Ibrahim ◽  
Manjree Agarwal ◽  
Jeong Oh Yang ◽  
Muslim Abdulhussein ◽  
Xin Du ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Volatile Organic Compounds ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Organic Compounds ◽  
Growth Regulators ◽  
Naphthalene Acetic Acid ◽  
Flame Ionization ◽  
Three Phase ◽  
Volatile Organic

The study focused on the influence of the plant growth regulators (PGRs) benzyladenine (BA) and naphthalene acetic acid (NAA) on the production of volatile organic compounds (VOCs) from the flowers of two modern rose varieties, Hybrid Tea and Floribunda. Thirty-six plants of Hybrid Tea and Floribunda were tested. Benzyladenine and naphthalene acetic acid were applied at 0, 100 and 200 mg/L to both rose varieties. Gas chromatography, coupled with flame ionization detection and mass spectrometry, was used to analyze and identify the volatile organic compounds from the flowers. A three-phase fiber 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane was used to capture VOCs, at 2, 4 and 8 weeks, and 4 weeks was selected as it had the highest peak area. In total, 81 and 76 VOCs were detected after treatment of both rose varieties with BA and NAA, respectively. In addition, 20 compounds, which had significant differences between different treatments, were identified from both rose varieties. The majority of VOCs were extracted after the application of 200 mg (BA and NAA) /L of formulation, and four important compounds, cis-muurola-4(141)5-diene, y-candinene, y-muurolene and prenyl acetate, increased significantly compared to the controls. These compounds are commercially important aroma chemicals. This study used the rapid and solvent-free SPME method to show that BA and NAA treatments can result in significant VOC production in the flowers of two rose varieties, enhancing the aromatic value of the flowers. This method has the potential to be applied to other valuable aromatic floricultural plant species.

scholarly journals Volatile Organic Compounds of Kaffir Lime (Citrus hystrix DC.) Leaves Fractions and their Potency as Traditional Medicine

2017 ◽  
Vol 14 (4) ◽  
pp. 1235-1250 ◽  
Author(s):  
Elsa Dilla Dertyasasa ◽  
Woro Anindito Sri Tunjung
Keyword(s):  
Fatty Acids ◽  
Volatile Organic Compounds ◽  
Ethyl Acetate ◽  
Traditional Medicine ◽  
Volatile Compounds ◽  
Organic Compounds ◽  
Fatty Alcohols ◽  
Crude Extracts ◽  
Volatile Organic ◽  
Long Chain

ABSTRACT: Previous studies have reported that a number of organic compounds are present in kaffir lime (Citrus hystrix DC.) leaf extracts. Further research is needed to purify these compounds and determine which are biologically active. The objective of this study is to identify the volatile organic compounds of kaffir lime leaf crude extracts and fractions and to study their bioactivity. Fractionation was performed by the double maceration method, using hexane as the second solvent. TLC was performed to analyze the qualitative separation, whereas the individual constituents were detected using GC-MS. Our results showed that chloroform and ethyl acetate crude extracts contained various volatile organic compounds such as fatty acids, fatty alcohols, prenol lipids, sterol lipids, terpenoids and long chain alkanes. Fractionation separated these compounds into non-hexane fractions, which contained less volatile compounds, and hexane fractions. The volatile compounds of non-hexane fractions were identified to be long chain alkanes, meanwhile the hexane fractions contained terpenoids, fatty acids, fatty alcohols, prenol lipids and sterol lipids. Palmitic acid and terpenoids, such as citronellyl propionate, nerolidol, citronella and caryophyllene oxide were found to be the most dominant bioactive compounds in chloroform and ethyl acetate crude extract and their hexane fractions, which were reported to possess cytotoxicity against cancer cells. Meanwhile in non-hexane fractions, long chain alkanes such as triacontane and hentriacontane were found to be the most dominant bioactive compound which also possessed cytotoxic effect. In conclusion, fractionation using the double maceration method yielded different volatile organic compounds composition with different biological activities. The crude extracts and fractions of kaffir lime leaves were potential to be developed as a traditional medicine for cancer treatment.

scholarly journals Potential of antimicrobial volatile organic compounds to control Sclerotinia sclerotiorum in bean seeds

2011 ◽  
Vol 46 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Maurício Batista Fialho ◽  
Maria Heloisa Duarte de Moraes ◽  
Annelise Roberta Tremocoldi ◽  
Sérgio Florentino Pascholati
Keyword(s):  
Volatile Organic Compounds ◽  
Ethyl Acetate ◽  
Organic Compounds ◽  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
In Vitro Assays ◽  
Phytopathogenic Fungus ◽  
Volatile Organic ◽  
Ethyl Octanoate

The objective of this work was to evaluate the potential of an artificial mixture of volatile organic compounds (VOCs), produced by Saccharomyces cerevisiae, to control Sclerotinia sclerotiorum in vitro and in bean seeds. The phytopathogenic fungus was exposed, in polystyrene plates, to an artificial atmosphere containing a mixture of six VOCs formed by alcohols (ethanol, 3-methyl-1-butanol, 2-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and ethyl octanoate), in the proportions found in the atmosphere naturally produced by yeast. Bean seeds artificially contamined with the pathogen were fumigated with the mixture of VOCs in sealed glass flasks for four and seven days. In the in vitro assays, the compounds 2-methyl-1-butanol and 3-methyl-1-butanol were the most active against S. sclerotiorum, completely inhibiting its mycelial growth at 0.8 µL mL-1, followed by the ethyl acetate, at 1.2 µL mL-1. Bean seeds fumigated with the VOCs at 3.5 µL mL-1 showed a 75% reduction in S. sclerotiorum incidence after four days of fumigation. The VOCs produced by S. cerevisiae have potential to control the pathogen in stored seeds.

scholarly journals Fabrication of Diatomite/Silicalite-1 Composites and Their Property for VOCs Adsorption

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 551 ◽  
Author(s):  
Yutong Liu ◽  
Tao Tian
Keyword(s):  
Volatile Organic Compounds ◽  
Ethyl Acetate ◽  
Adsorption Capacity ◽  
Organic Compounds ◽  
Hydrothermal Reaction ◽  
Selective Adsorption ◽  
Maximum Adsorption Capacity ◽  
Voc Adsorption ◽  
Hierarchical Porous ◽  
Volatile Organic

Adsorption technology is an effective method to remove volatile organic compounds (VOCs). In this work, we prepared hierarchical porous materials using modified diatomite (Dt) as a support and nano-sized silicalite-1 (S-1) seeds as inorganic fillers, which were applied to adsorb volatile organic compounds (VOCs). The characterization of the composites indicated that S-1 was successfully coated onto the surface of modified Dt, and the best surface area of the composites was 398.8 m2/g, nearly 40 times as large as Dt. The adsorption capacities of Dt/S-1 composites for three probe VOCs (ethyl acetate, acetone, and toluene) were rather superior to Dt, and the composites had preferential adsorption selectivity for ethyl acetate. Effects of seeded zeolite contents and hydrothermal conditions for the adsorption capacity of composites were discussed in this paper. The composite seeded with 5 wt% S-1 zeolite, which was subsequently synthesized by hydrothermal reaction at 100 °C for four days, showed the maximum adsorption capacity (1.31 mmol/g for ethyl acetate). The pseudo second-order model provided a perfect fit to adsorption kinetics, while the Langmuir model agreed the best with the adsorption isotherms. In addition, the composites had selective adsorption to ethyl acetate among these three probes VOCs. The regeneration experiments were also carried out, and the adsorption efficiency of the adsorbents was still up to 67% after five adsorption–desorption cycles. The hierarchical porous Dt/S-1 composites have an excellent VOC adsorption performance, satisfactory selectivity, and recycling ability.

scholarly journals MASS SPECTROMETRIC STUDIES OF THE COMPOSITION OF VOLATILE ORGANIC COMPOUNDS RELEASED BY VARIOUS FUNGAL SPECIES OF GENUS LECANICILLIUM

2021 ◽  
Vol 31 (4) ◽  
pp. 71-78
Author(s):  
A. G. Kuzmin ◽  
Keyword(s):  
Acetic Acid ◽  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Plant Protection ◽  
Fungal Species ◽  
Quadrupole Mass ◽  
Volatile Organic ◽  
First Time ◽  
Chemical Pesticides

For the first time, the quantitative and qualitative composition of volatile organic compounds (VOCs), released by strains of various species of entomopathogenic fungi (EF) of the genus Lecanicillium, was studied using a quadrupole mass spectrometer. Lecanicillium fungi are used as an alternative to chemical pesticides for plant protection. The main detected components of the gas phase over the EF mycelium on the 10th day of growing on the agar Czapek's medium were carbon dioxide (5–20%), oxygen (0.1–15%), acetone (0.2–12 ppm), pentane (up to 0.5 ppm), acetic acid (up to 0.15 ppm). Acetone and pentane were found in the VOCs of all studied strains, acetic acid — in 5 strains belonging to different species, in other strains it appeared after a longer period of time, or was absent completely. Among the VOCs of some strains, substances such as hexyl acetate, sulfur dioxide were found in small quantities. These substances may be responsible for the pathogenic and repellent properties of the studied fungi with respect to phytophages.

scholarly journals Assessment methodology for volatile organic compounds from leachate treatment and other waste handling activities

2019 ◽  
pp. 291-294
Author(s):  
Lennart Mårtensson ◽  
Lars Thörneby ◽  
Staffan Bergström ◽  
Diauddin Nammari ◽  
Lennart Mathiasson
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Vapour Phase ◽  
Health Concern ◽  
Glycol Ethers ◽  
Leachate Treatment ◽  
Model Studies ◽  
Volatile Organic ◽  
Before And After ◽  
Treatment Procedures

Volatile organic compounds (VOC) are typically defined as those predominantly presentin the vapour phase in air at ambient temperature, They range in volatility from methaneto n-e 16 above and include all chemical groups - alcohols, ketones, aldehydes, esters,glycol ethers, halogens and hydrocarbons, Many of the voes are produced and emittedwhen organic matter decomposes from microbiological activity, A great number ofvolatile compounds been identified in the air in the vicinity of landfills, voes emittedfrom landfills pose as health concern and odour annoyance for the neighbourhood, Highconcentrations of voes have also been identified in the working environments at wastehandling facilities, Emissions of volatile organics from leachate, and how the treatmentsystem affects the fate of the voes have been reported, A variety of different samplingstrategies and sampling media can be used to address different monitoring requirements,including adsorption tubes and impingers with a suitable absorption solution, Finalanalysis of voes can be performed with a combination of thermodesorption ofadsorption tubes and Ge-MS, Model studies of the emission of voes from the watersurface, at the actual site in ponds or in the laboratory, can be performed in order tofacilitate budget calculations using a special designed hood, Results from analysis ofleachate before and after treatment procedures, using purge and trap methodology, showshow some identified voes such as for example benzene, toluene, xylen and trimethylbenzene are to some extent removed from the liquid,

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