Category: alcohols-buliding-blocks

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

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

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

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

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

Rodgers, Timothy F. M. published the artcileComment on “”A Database of Experimentally Derived and Estimated Octanol-Air Partition Ratios (KOA)”” [J. Phys. Chem. Reference Data 50, 043101 (2021)], SDS of cas: 111-87-5, the main research area is polemic octanol air partition ratio database.

A polemic in response to Baskaran et al. is provided. Baskaran et al. presented an excellent database of KOA values that will be of immense value to the field going forward. Included in their article is a thorough discussion of the techniques used to measure or estimate KOA and their strengths and limitations. We are writing because the authors call into question, on the basis of polarity, many KOA measurements made with the gas chromatog.-retention time (GC-RT) technique. Baskaran et al. supported their suggested threshold with a finding of bias between the GC-RT measured K OA values and in silico estimations Although we agree that the GC-RT method with a non-polar column should not be used for highly polar mols. and that bas- ing a decision rule on the Abraham aA and bB parameters may be reasonable, we disagree with the threshold suggested by Baskaran et al. of aA + bB > 0.5. In our view, there is inadequate exptl. evidence to support such a stringent limit at this time. In this Comment, we treated the threshold proposed as a classifier model and applied it to data from their database. This showed that the threshold of aA + bB > 0.5 had a false-pos. rate of between 50% and 70%, rejecting many data points that did not show evidence of bias. (c) 2022 American Institute of Physics.

Journal of Physical and Chemical Reference Data published new progress about Air. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, SDS of cas: 111-87-5.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Nedyalkova, Miroslava A. published the artcileCalculating the Partition Coefficients of Organic Solvents in Octanol/Water and Octanol/Air, Safety of n-Octanol, the main research area is partition coefficient organic solvent octanol water octanol air calculation.

Partition coefficients define how a solute is distributed between two immiscible phases at equilibrium The exptl. estimation of partition coefficients in a complex system can be an expensive, difficult, and time-consuming process. Here a computational strategy to predict the distributions of a set of solutes in two relevant phase equilibrium is presented. The octanol/water and octanol/air partition coefficients are predicted for a group of polar solvents using d. functional theory (DFT) calculations in combination with a solvation model based on d. (SMD) and are in excellent agreement with exptl. data. Thus, the use of quantum-chem. calculations to predict partition coefficients from free energies should be a valuable alternative for unknown solvents. The obtained results indicate that the SMD continuum model in conjunction with any of the three DFT functionals (B3LYP, M06-2X, and M11) agrees with the observed exptl. values. The highest correlation to exptl. data for the octanol/water partition coefficients was reached by the M11 functional; for the octanol/air partition coefficient, the M06-2X functional yielded the best performance. To the best of our knowledge, this is the first computational approach for the prediction of octanol/air partition coefficients by DFT calculations, which has remarkable accuracy and precision.

Journal of Chemical Information and Modeling published new progress about Air. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, Safety of n-Octanol.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Lei, Ying Duan published the artcileMeasuring the Octan-1-ol Air Partition Coefficient of Volatile Organic Chemicals with the Variable Phase Ratio Headspace Technique, Formula: C8H18O, the main research area is octanol air partition VOC variable phase ratio headspace; volatile organic compound partition octanol air.

There is a need to determine the equilibrium partition coefficient of volatile organic chems. between octan-1-ol and the gas phase, KOA, because it is being used to assess the potential for respiratory elimination from air-breathing organisms. Here we test the suitability of the variable phase ratio headspace technique for determining the KOA of volatile organic substances, using acetone, acetonitrile, Et acetate, 1,2-dichloroethane, propan-1-ol, butan-1-ol, p-xylene, trans-decalin, 1,3-dichlorobenzene, and 1,2,3,4-tetramethylbenzene as test substances. The method was found capable of measuring KOA values at temperatures between 40 and 110 °C in the range from 50 to 2000 with a relative standard error of approx. 8%. This allowed for the derivation of KOA values at 25 °C below 10 000. Higher KOA values close to the threshold for respiratory elimination of 100 000 cannot be determined reliably with this method.

Journal of Chemical & Engineering Data published new progress about Air. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, Formula: C8H18O.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Moon, Jeong-Yi published the artcileSeparation of scandium from yttrium in aqueous chloride media by solvent extraction with an acidic phosphinate extractant, Application of n-Octanol, the main research area is scandium yttrium separation chloride solvent extraction acidic phosphinate extractant.

Separation of scandium (Sc) from yttrium (Y) in aqueous chloride media was investigated by solvent extraction with bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272). Conventional slope anal. method revealed the extraction equilibrium formulation of the metals. Sc is more strongly extracted than Y by Cyanex 272, and the separation factor of the metals is quite high at 2.82 × 105. Complete stripping of Sc from the loaded organic solution of Cyanex272 could not be achieved, even with a high concentration of hydrochloric acid. Addition of 1-octanol as a modifier to the organic phase decreased the extractability of Sc, leading to successful stripping of Sc from the loaded organic solution

Solvent Extraction Research and Development, Japan published new progress about pH. 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

Englezos, Vasileios published the artcileSaccharomyces cerevisiae-Starmerella bacillaris strains interaction modulates chemical and volatile profile in red wine mixed fermentations, Application In Synthesis of 505-10-2, the main research area is volatile organic compound Saccharomyces Starmerella red wine fermentation; Extracellular metabolites; Mixed fermentation; Non-Saccharomyces; Starmerella bacillaris; Yeast interactions.

The use of Starmerella bacillaris in combination with Saccharomyces cerevisiae is considered as a state-of-the-art biol. application to modulate wine composition This application implies a detailed understanding of yeast-yeast interactions during mixed fermentations and their effect on the composition of the resulting wines. In this context, ten com. S. cerevisiae strains were used as partners of an indigenous, previously characterized Starm. bacillaris strain in order to get a better insight into the impact of S. cerevisiae strain employed. The different combinations of strains tested influenced the growth dynamics, the fermentation behavior and, as a consequence, wine composition in a couple-dependent manner. In addition, wines produced from mixed fermentations had significantly lower levels of ethanol, acetic acid and Et acetate, and showed higher amounts of glycerol, higher alcs. and esters compared to pure S. cerevisiae control fermentations This study reveals the importance of S. cerevisiae strain choice on the chem. composition of the wines produced from mixed culture fermentations with Starm. bacillaris.

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

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts