Author: tianli

Whelan, Michael J. published the artcileApplication of multimedia models for understanding the environmental behavior of volatile methylsiloxanes: Fate, transport, and bioaccumulation, Product Details of C8H18O, the main research area is review volatile methylsiloxane environmental behavior multimedia model; Environmental fate; Long-range transport potential; Multimedia fate and transport models; Persistence; Volatile methylsiloxane.

Multimedia fate and transport models (MFTMs) describe how chems. behave in the environment based on their inherent properties and the characteristics of receiving systems. We critically review the use of MFTMs for understanding the behavior of volatile methylsiloxanes (VMS). MFTMs have been used to predict the fate of VMS in wastewater treatment, rivers, lakes, marine systems, and the atm., and to assess bioaccumulation and trophic transfers. More widely, they have been used to assess the overall persistence, long-range transport potential (LRTP), and the propensity for atm.-surface exchange. The application of MFTMs for VMS requires particularly careful selection of model inputs because the properties of VMS differ from those of most organic compounds For example, although n-octanol/water partition coefficient (KOW) values are high, air:water partition coefficient (KAW) values are also high and n-octanol/air partition coefficient (KOA) values are relatively low. In addition, organic carbon/water partition coefficient (KOC) values are substantially lower than expectations based on KOW. This means that most empirical relationships between KOC and KOW are not appropriate. Good agreement between modeled and measured concentrations in air, sediment, and biota indicates that our understanding of environmental fate is reasonable. VMS compounds are “”fliers”” that principally partition to the atm., implying high LRTP, although they have low redeposition potential. They are degraded in air (half-lives 3-10 days) and, thus, have low overall persistence. In water, exposure can be limited by hydrolysis, volatilization, and partitioning to sediments (where degradation half-lives are likely to be high). In food webs, they are influenced by metabolism in biota, which tends to drive trophic dilution (i.e., trophic magnification factors are often but not always <1). Key remaining uncertainties include the following: (i) the strength and direction of the temperature dependence for KOC; (ii) the fate of atm. reaction products; and (iii) the magnitude of emissions to wastewater. Integrated Environmental Assessment and Management published new progress about Air. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, Product Details of C8H18O.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Reyes-Jurado, Fatima published the artcileFungal inactivation on Mexican corn tortillas by means of thyme essential oil in vapor-phase, Product Details of C10H18O, the main research area is thymus vulgaris vapor phase corn tortillas mexican fungal inactivation; Antifungal activity; Essential oil; Tortilla.

Antifungal activity of thyme (Thymus vulgaris) essential oil (EO) in vapor-phase was tested against representative fungi in corn tortillas. The chem. composition of studied EO was analyzed by gas chromatog.-mass spectroscopy, and its major components were linalool, thymol, and p-cymene. The antifungal activity was evaluated by determining the growth of Aspergillus niger or Penicillium expansum after exposure to EO vapors. The in vitro min. inhibitory concentration (MIC) of the EO was determined by the inverted lid technique, while in situ MIC was determined on the corn tortillas inside an airtight container. The MICs obtained ranged from 160 to 200μL of thyme EO/Lof air for in vitro conditions and 550-850μL of the EO/Lof air in corn tortillas. The modified Gompertz model adequately described in vitro mold growth curves. Thyme EO was effective in preventing or significantly delaying growth of the contaminating molds on corn tortillas.

Current Research in Food Science published new progress about Air. 124-76-5 belongs to class alcohols-buliding-blocks, name is rel-(1R,2R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-ol, and the molecular formula is C10H18O, Product Details of C10H18O.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Mackay, Donald published the artcileKinetic Delay in Partitioning and Parallel Particle Pathways: Under-appreciated Aspects of Environmental Transport, Category: alcohols-buliding-blocks, the main research area is hydrophobic chem kinetic delay organic medium equilibrium condition attainment; parallel particle pathway hydrophobic chem equilibrium condition attainment.

General conditions under which highly hydrophobic chems. or, more generally, chems. with high partition ratios (HPR) in water or air, may experience unexpectedly long kinetic delays in approaching equilibrium conditions with organic media are outlined. Such a hydrophobic delay for KOW, or an aerophobic delay for KOA, may be misinterpreted as being caused by a change in partitioning behavior or mechanism, resulting in development of non-linear regression models describing inter-media partitioning. The partitioning is fundamentally linear but is distorted by a kinetic delay in partitioning. To illustrate this concept, fundamental equations describing the diffusive equilibration processes, including a complementary transport mechanism termed a parallel particle pathway (PPP), were compiled. Such a mechanism may simultaneously occur, shortening the HPR delay and complicating interpretation. In addition, five examples where the HPR delay explains observed and occasionally difficult-to-interpret environmental behavior of chems., i.e., air-aerosol partitioning, chem. accumulation in indoor dust and surfaces, air/vegetation partitioning, internal transport in organisms, and fish bioaccumulation and toxicity studies, are described. The authors believe the general HPR delay and PPP issues deserve exposure as a commonly occurring, often under-appreciated process.

Environmental Science & Technology published new progress about Air. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, Category: alcohols-buliding-blocks.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Petronilho, Silvia published the artcileRevealing the usefulness of aroma networks to explain wine aroma properties: a case study of Portuguese wines, Application of 3-(Methylthio)propan-1-ol, the main research area is Arinto white Bical Baga Castelao wine aroma network; aroma network; aroma sensory analysis; gas chromatography; monovarietal wines; volatile compounds.

Wine aroma is the result of complex interactions between volatile compounds and non-volatile ones and individual perception phenomenon. In this work, an aroma network approach, that links volatile composition (chromatog. data) with its corresponding aroma descriptors was used to explain the wine aroma properties. This concept was applied to six monovarietal wines from Bairrada Appellation (Portugal) and used as a case study. A comprehensive determination of the wines’ volatile composition was done (71 variables, i.e., volatile components), establishing a workflow that combines extraction techniques and gas chromatog. anal. Then, a bipartite network-based approach consisting of two different nodes was built, one with 19 aroma descriptors, and the other with the corresponding volatile compound(s). To construct the aroma networks, the odor active values were calculated for each determined compound and combined with the bipartite network. Finally, the aroma network of each wine was compared with sensory descriptive anal. The anal. of the specific aroma network of each wine revealed that Sauvignon Blanc and Arinto white wines present higher fruity (esters) and sweet notes (esters and C13 norisoprenoids) than Bical wine. Sauvignon Blanc also exhibits higher toasted aromas (thiols) while Arinto and Bical wines exhibit higher flowery (C13 norisoprenoids) and herbaceous notes (thiols), resp. For red wines, sweet fruit aromas are the most abundant, especially for Touriga Nacional. Castelão and Touriga Nacional wines also present toasted aromas (thiols). Baga and Castelão wines also exhibit fusel/alc. notes (alcs.). The proposed approach establishes a chem. aroma fingerprint (aroma ID) for each type of wine, which may be further used to estimate wine aroma characteristics by projection of the volatile composition on the aroma network.

Molecules published new progress about Wine. 505-10-2 belongs to class alcohols-buliding-blocks, name is 3-(Methylthio)propan-1-ol, and the molecular formula is C4H10OS, Application of 3-(Methylthio)propan-1-ol.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Laboratoire “Dauphin” published the artcileThe determination of citronellal, HPLC of Formula: 42822-86-6, the main research area is .

Cf. Holtappel, C. A. 22, 1214. The original Dauphin method is as follows: weigh 2 g. oil in a 100-cc. flask, add 20 cc. of 5% alc. NH2OH.HCl previously neutralized to helianthin, immediately titrate the liberated HCl with 0.2 N KOH in presence of helianthin. Holtappel’s modifications consist essentially in cooling the solution with ice, use of excess alkali with back titration after 15 min., and use of bromothymol blue instead of helianthin. Investigation of the effects of temperature showed negligible variations (maximum 0.5%) from 0° to 35°. Investigation of the causes of the irregularities in results obtained by Holtappel brought out the following facts: (1) citronellal is cyclicized by strong acids into isopulegol and its derivatives, there being formed chiefly hydroxy-3-ethoxy-8-p-menthane in alc. solution, while in hydro-alc. solution there is formed a mixture of this compound with 3,8-p-menthane diol; (2) neither of these compounds combines with NH2OH.HCl, and their formation leads to low results; (3) in strongly alc. solution these reactions are of secondary importance, there being formed citronellal ethylacetal, which protects the aliphatic mol. against cyclization; (4) contrary to generally accepted data, this reaction is almost instantaneous, even at -15°; (5) slight acidity catalyzes oximation before cyclization can take place to any appreciable extent. It is concluded that: (1) helianthin should be used as indicator, as the turning point of bromothymol blue is at such a low pH value of the solution that appreciable cyclization can occur, while a light red color with helianthin indicates optimum conditions for oximation and absence of cyclization; (2) the alc. KOH should be added sufficiently quickly to avoid production for any appreciable time of the distinct red characteristic of relatively high acidity, and sufficiently slowly to prevent high alkalinity which might slow the reaction and even prevent it from going to completion through formation of the fairly stable acetal. The fact that Holtappel obtained lower results by oximation in alk. solution than by oximation at low temperature in acid solution is attributed to the fact that, because of the use of bromothymol blue instead of helianthin, the true effects of acidity could not be detected. The original Dauphin method is more simple and rapid than Holtappel’s modification and is as accurate as the latter. The method is being applied in the Dauphin Laboratories to the determination of ketones in all essential oils (the determination of citronellal being the most delicate); and where the speed of the reaction is relatively low, by plotting curves the presence of several ketones in the same oil can frequently be brought out very clearly. The method is particularly suitable for determination of menthone in oil of mint, instead of the usual method of reducing with Na, washing, acetylating and saponifying

Parfums de France published new progress about Oils. 42822-86-6 belongs to class alcohols-buliding-blocks, name is 2-(2-Hydroxypropan-2-yl)-5-methylcyclohexanol, and the molecular formula is C10H20O2, HPLC of Formula: 42822-86-6.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Tursun, Ayse Ozlem published the artcileEffects of Elevated Temperature and Carbon Dioxide Concentrations on Aromatic Compounds of Stevia rebaudiana, Synthetic Route of 584-02-1, the main research area is Stevia caryophyllene nerolidol oxide temperature carbon dioxide.

Abstract: A global rise in CO2 concentration and temperature levels can impact the living part of the earth including the plants. Stevia or candy leaf (Stevia rebaudiana Bertoni) is a medicinal aromatic plant that produces several useful chem. compounds Studies were carried out in a fully automated greenhouse in order to determine the response of aromatic compounds of stevia leaves to different CO2 concentrations and temperature levels. This study had four treatments including (1) 26 ± 1/16 ± 1 °C day/night temperature plus 400 ± 50 ppm CO2 concentration [control], (2) 29 ± 1/19 ± 1 °C day/night temperature plus 600 ± 50 ppm CO2 concentration, (3) 32 ± 1/22 ± 1 °C day/night temperature plus 800 ± 50 ppm CO2 concentration and (4) 35 ± 1/25 ± 1 °C day/night temperature plus 1000 ± 50 ppm CO2 concentration Results of the study showed that yield of total aromatic compounds ranged between 12.65 and 13.65 μg/g for stevia . Generally, concentrations of the compounds such as ketones, aldehydes and alcs. were decreased with increase in concentration of CO2 and temperature Terpenes were the compounds whose concentrations were increased with increase in concentration of CO2 and temperature The climatic conditions did not cause a significant change in the aromatic compounds of stevia.

Sugar Tech published new progress about Leaf. 584-02-1 belongs to class alcohols-buliding-blocks, name is 3-Pentanol, and the molecular formula is C5H12O, Synthetic Route of 584-02-1.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Silva, Marcela F. published the artcileVolatile emissions of watercress (Nasturtium officinale) leaves and passion fruit (Passiflora edulis) seeds against Meloidogyne incognita, HPLC of Formula: 584-02-1, the main research area is Nasturtium Passiflora Meloidogyne leaf seed volatile organic compound nematicidal; Nasturtium officinale; Passiflora edulis; biofumigation; root-knot nematodes; volatile organic compounds.

However, the toxicity of VOCs from watercress leaves (Nasturtium officinale) and passion fruit seeds (Passiflora edulis) against PPNs has not yet been studied. RESULTS : Biofumigation with watercress leaves and passion fruit seeds reduced the infectivity and reproduction of Meloidogyne incognita in tomato plants. The VOCs emitted by watercress leaves and passion fruit seeds caused immobility of M. incognita second-stage juveniles (J2). The reduction in infectivity and reproduction of M. incognita reached 89% and 99%, resp., when J2 were exposed to watercress VOCs. Addnl., water exposed to VOCs emitted by watercress caused 79% M. incognita J2 mortality. The volatilome of the toxic water contained 12 compounds, mainly alcs. The emissions from watercress leaves and passion fruit seeds contained 26 and 12 compounds, resp., according to gas chromatog.-mass spectrometry anal. The 1-octanol occurring in watercress emissions demonstrated in vitro and in vivo nematicidal activity against M. incognita, with a LD necessary to cause 50% mortality (LC50) of 382.5μg mL-1. CONCLUSIONS : Watercress leaf and passion fruit seed macerates emitted VOCs with nematicidal activity against M. incognita. The compound 1-octanol identified in watercress emissions may be useful for the nematicide-producing industry.

Pest Management Science published new progress about Leaf. 584-02-1 belongs to class alcohols-buliding-blocks, name is 3-Pentanol, and the molecular formula is C5H12O, HPLC of Formula: 584-02-1.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Fan, Yuzhen published the artcileDark respiration rates are not determined by differences in mitochondrial capacity, abundance and ultrastructure in C4 leaves, COA of Formula: C4H6O5, the main research area is C4 photosynthesis leaf bundle sheath mitochondria light respiration; C4 photosynthetic pathway; C4 plants; bundle sheath; mitochondria; mitochondrial ultrastructure; respiration.

Our understanding of the regulation of respiration in C4 plants, where mitochondria play different roles in the different types of C4 photosynthetic pathway, remains limited. We examined how leaf dark respiration rates (Rdark), in the presence and absence of added malate, vary in monocots representing the three classical biochem. types of C4 photosynthesis (NADP-ME, NAD-ME and PCK) using intact leaves and extracted bundle sheath strands. In particular, we explored to what extent rates of Rdark are associated with mitochondrial number, volume and ultrastructure. Based on examination of a single species per C4 type, we found that the respiratory response of NAD-ME and PCK type bundle sheath strands to added malate was associated with differences in mitochondrial number, volume, and/or ultrastructure, while NADP-ME type bundle sheath strands did not respond to malate addition In general, mitochondrial traits reflected the contributions mitochondria make to photosynthesis in the three C4 types. However, despite the obvious differences in mitochondrial traits, no clear correlation was observed between these traits and Rdark. We suggest that Rdark is primarily driven by cellular maintenance demands and not mitochondrial composition per se, in a manner that is somewhat independent of mitochondrial organic acid cycling in the light.

Plant, Cell & Environment published new progress about Leaf. 97-67-6 belongs to class alcohols-buliding-blocks, name is (S)-2-hydroxysuccinic acid, and the molecular formula is C4H6O5, COA of Formula: C4H6O5.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Romero, Richard R. published the artcileA study of the reaction kinetics of polyisocyanurate foam formulations using real-time FTIR, Name: N2-(2-Hydroxyethyl)-N1,N1,N2-trimethyl-1,2-ethylenediamine, the main research area is polyisocyanurate foam formulation reaction kinetics real time FTIR.

The use of alternative blowing agents for the production of polyisocyanurate (PIR) rigid foam has created a need to better understand how various catalysts participate in isocyanurate formation. The improvement of isocyanate conversion to isocyanurate is one approach to overcome the greater flammability inherent with the use of hydrocarbons. In situ Fourier Transform IR (FTIR) has been used to follow the reaction kinetics of PIR development during foam preparation The activity of amine catalysts for isocyanate conversion is characterized through the use of in situ FTIR. Identification of the reaction products formed from the blowing, gelling, and trimerization reactions provides the opportunity to profile the catalytic effects as the reaction proceeds. Several traditional amine catalysts used by PIR foam manufacturers have been evaluated. The design of catalyst blends in PIR formulation can now be based upon the results of the catalytic activity characterization. In this article, the focus is on understanding the synergies between catalysts used in PIR formulations. Real-time in situ FTIR is the technique of choice for the evaluation of catalysts blends for optimal performance and processing properties.

Journal of Cellular Plastics published new progress about Flow. 2212-32-0 belongs to class alcohols-buliding-blocks, name is N2-(2-Hydroxyethyl)-N1,N1,N2-trimethyl-1,2-ethylenediamine, and the molecular formula is C7H18N2O, Name: N2-(2-Hydroxyethyl)-N1,N1,N2-trimethyl-1,2-ethylenediamine.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Fikarova, K. published the artcileAutomated continuous-flow in-syringe dispersive liquid-liquid microextraction of mono-nitrophenols from large sample volumes using a novel approach to multivariate spectral analysis, Application of n-Octanol, the main research area is syringe liquid microextraction nitrophenol analysis water pollution; Background simulation; Continuous-flow dispersive liquid-liquid microextraction; Lab-in-Syringe; Large volume sample pre-treatment; Mono-nitrophenols; Multivariate spectrum analysis.

Continuous magnetic stirring-assisted dispersive liquid-liquid extraction followed by dispersive backextn. as a novel pre-treatment technique for adaptable and milliliter volumes of environmental samples has been developed. The procedure was automated using the technique “”Lab-In-Syringe””. The void of the automated syringe pump was used as size-adaptable extraction chamber. By a flow channel in the syringe piston, continuous flow through the syringe void was enabled. 1-Octanol was used as an extractant and dispersed by the action of a magnetic stirring bar, which was placed inside the syringe and driven by an external rotating magnetic field. Extract washing and dispersive backextn. in an alk. aqueous acceptor phase were carried out after the preceding extraction from the acidified water sample. Analyte determination was achieved using multivariate spectrum anal. The method was applied to determine priority pollutants, mono-nitrophenols, in surface water and enabled to reach limits of detection for o-, m-, p-nitrophenol (λ = 418, 390, 400 nm, resp.) of 0.14, 0.26, and 0.02 μmol L-1 (19.5, 36.2, and 2.8 μg L-1), resp. Under optimized conditions, relative standard deviations were generally less than 5% and enrichment factors of o-, m-, p-nitrophenol 19, 25, and 21, resp., were achieved using sample volumes of up to 24 mL. Average recoveries of o-, m-, p-nitrophenol from spiked surface water were 94, 82, and 92%, resp. The concentration of humic acid was found 6-times reduced with respect to the analyte. In addition, adding spectral background modeling allowed nitrophenol determination with precision adequate for routine anal.

Talanta published new progress about Flow. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, Application of n-Octanol.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts