INTERRELATION OF CHEMICAL AND FRACTIONAL STRUCTURES OF RIVER SEDIMENTS

AbstractThe development of high-throughput liquid chromatographic techniques for the analysis of styrene-butyl acrylate (SBA) copolymers is discussed. The analysis time in size-exclusion chromatography (SEC) can be reduced to about 3 min per sample when high-throughput SEC columns and high flow rates are used. In gradient HPLC, small columns with improved separation efficiencies can be applied. The time requirements can be decreased to less than 2 min per sample. Using the high-throughput HPLC technique, the chemical composition distribution of high-conversion SBA copolymers can be analyzed in a fast and efficient way. The calibration of HPLC separation is conducted by coupling the HPLC system with FTIR through the LC-transform interface. A comparison of the chemical compositions of the copolymers obtained by 1H NMR, off-line FTIR and coupled HPLCFTIR verifies the accuracy of the high-throughput copolymer analysis approach.

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Relationship between Chemical Composition and the Amount of Phosphorus Adsorbed

Materials Science Forum ◽

10.4028/www.scientific.net/msf.695.141 ◽

2011 ◽

Vol 695 ◽

pp. 141-144

Author(s):

Eiji Watanabe ◽

Kaori Nishizawa ◽

Masaki Maeda

Keyword(s):

Chemical Composition ◽

Chemical Compositions ◽

Natural Materials ◽

Adsorption Behaviors ◽

Relationship Of

Relationship of the adsorption behaviors of phosphorus with several natural materials and artificial HAS-clay with various chemical compositions was investigated. The amounts of phosphorus adsorbed by them were closely related with the contents of aluminum in the material. It was found that the higher the aluminum contents of material, larger the amount of phosphorus were adsorbed.

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Soil and Leaf Nutrients Drivers on the Chemical Composition of the Essential Oil of Siparuna muricata (Ruiz & Pav.) A. DC. from Ecuador

Molecules ◽

10.3390/molecules26102949 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2949

Author(s):

Juan I. Burneo ◽

Ángel Benítez ◽

James Calva ◽

Pablo Velastegui ◽

Vladimir Morocho

Keyword(s):

Gas Chromatography ◽

Chemical Composition ◽

Secondary Metabolites ◽

Essential Oil ◽

Chemical Elements ◽

Climatic Conditions ◽

Gas Chromatography Mass Spectrometry ◽

Chemical Compositions ◽

Leaf Nutrients ◽

First Time

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of β-pinene, limonene, δ-elemene, β-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.

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Relationship between the Optical Properties and Chemical Composition of Urban Aerosol Particles in Lithuania

Advances in Meteorology ◽

10.1155/2018/8674173 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Julija Pauraite ◽

Kristina Plauškaitė ◽

Vadimas Dudoitis ◽

Vidmantas Ulevicius

Keyword(s):

Optical Properties ◽

Chemical Composition ◽

Organic Aerosol ◽

Single Scattering ◽

Chemical Compositions ◽

Spectra Analysis ◽

Average Value ◽

Aerosol Mass ◽

In Situ Investigation

In situ investigation results of aerosol optical properties (absorption and scattering) and chemical composition at an urban background site in Lithuania (Vilnius) are presented. Investigation was performed in May-June 2017 using an aerosol chemical speciation monitor (ACSM), a 7-wavelength Aethalometer and a 3-wavelength integrating Nephelometer. A positive matrix factorisation (PMF) was used for the organic aerosol mass spectra analysis to characterise the sources of ambient organic aerosol (OA). Five OA factors were identified: hydrocarbon-like OA (HOA), biomass-burning OA (BBOA), more and less oxygenated OA (LVOOA and SVOOA, respectively), and local hydrocarbon-like OA (LOA). The average absorption (at 470 nm) and scattering (at 450 nm) coefficients during the entire measurement campaign were 16.59 Mm−1 (standard deviation (SD) = 17.23 Mm−1) and 29.83 Mm−1 (SD = 20.45 Mm−1), respectively. Furthermore, the absorption and scattering Angström exponents (AAE and SAE, respectively) and single-scattering albedo (SSA) were calculated. The average AAE value at 470/660 nm was 0.97 (SD = 0.16) indicating traffic-related black carbon (BCtr) dominance. The average value of SAE (at 450/700 nm) was 1.93 (SD = 0.32) and could be determined by the submicron particle (PM1) dominance versus the supermicron ones (PM > 1 µm). The average value of SSA was 0.62 (SD = 0.13). Several aerosol types showed specific segregation in the SAE versus SSA plot, which underlines different optical properties due to various chemical compositions.

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Low Density Multi-principal Element Alloy from Al-Mg-Ca-Si-B System

Revista de Chimie ◽

10.37358/rc.19.7.7330 ◽

2019 ◽

Vol 70 (7) ◽

pp. 2315-2320

Author(s):

Victor Geanta ◽

Robert Ciocoiu ◽

Ionelia Voiculescu

Keyword(s):

Chemical Composition ◽

Chemical Element ◽

Mechanical Characteristics ◽

Cast Alloy ◽

Complex Oxides ◽

Scientific Paper ◽

Chemical Compositions ◽

Low Density ◽

Principal Element ◽

Research Stage

The scientific paper presents a numerical modeling of the chemical composition for the optimization of the multicomponent light alloys in the Al-Mg-Ca-Si-B system. The effects of the proportion of each chemical element on the main characteristics of the alloy based on the mixture rule and the correlation between the melting temperature and the modulus of elasticity were analyzed numerically. The model results has reveals that even other factors must be taken into account, i.e. the mechanical characteristics which varied significantly with changing of chemical compositions. A compromise was set, by slightly increasing the density to acquire better mechanical characteristics. The selected chemical composition was then used to obtain the new low density alloy. In current research stage we conclude that the as cast alloy comprises an inhomogeneous solid solution and complex oxides. Further studies are ongoing on the experimental alloy in various states (homogenization annealed and processed by plastic deformation).

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Comparison of chemical compositions of essential oils isolated by hydrodistillation from wild thyme (Thymus serpyllum L.) with use of Deryng and Clevenger apparatus

Herba Polonica ◽

10.2478/hepo-2014-0006 ◽

2014 ◽

Vol 60 (2) ◽

pp. 7-17 ◽

Cited By ~ 4

Author(s):

Aneta Wesołowska ◽

Monika Grzeszczuk ◽

Dorota Jadczak

Keyword(s):

Chemical Composition ◽

Essential Oil ◽

Essential Oils ◽

Methyl Ether ◽

The Other ◽

Chemical Compositions ◽

Distillation Apparatus ◽

Ms Analysis ◽

Wild Thyme ◽

Thymus Serpyllum

Abstract The aim of the studies conducted in 2012-2013 was to compare the chemical composition of essential oils isolated from wild thyme (Thymus serpyllum L.) by hydrodistillation in Deryng and Clevenger apparatus. GC-MS analysis of the isolated oils revealed that carvacrol (42.81-45.24%), γ-terpinene (7.68-9.04%), β-caryophyllene (5.28-9.10%), β-bisabolene (5.76-6.91%) and carvacrol methyl ether (4.92-6.09%) were the major components of all the samples. On the basis of the obtained data it was proved that the type of distillation apparatus had no significant effect on the content of the main essential oil constituents of wild thyme. However, based on the means for both years of the study it was proved that hydrodistillation in Deryng apparatus was more effective for carvacrol concentration, while in Clevenger apparatus - for y-terpinene and carvacrol methyl ether concentration. The type of distillation apparatus had no significant effect on the content of the other essential oil constituents.

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Seasonal and Circadian Rhythm of a 1,8-Cineole Chemotype Essential Oil of Calycolpus goetheanus From Marajó Island, Brazilian Amazon

Natural Product Communications ◽

10.1177/1934578x20933055 ◽

2020 ◽

Vol 15 (6) ◽

pp. 1934578X2093305

Author(s):

Edimara L. dos Santos ◽

Ananda M. Lima ◽

Vilmara Fabrícia dos S. Moura ◽

William N. Setzer ◽

Joyce Kelly R. da Silva ◽

...

Keyword(s):

Circadian Rhythm ◽

Chemical Composition ◽

Rainy Season ◽

Brazilian Amazon ◽

Dry Season ◽

Chemical Compositions ◽

Flame Ionization ◽

Group I ◽

Marajó Island ◽

Ionization Detectors

Chemical composition of essential oils (EOs) of Calycolpus genus have been reported in the literature. However, there is only 1 report about volatile profile from Calycolpus goetheanus. This work aims to evaluate the seasonal and circadian influences on EO composition and yield of C. goetheanus collected in Marajó Island, Brazilian Amazon. For the circadian study, the leaves were collected in January (rainy season) and July (dry season) every 3 hours during a period of 15 hours. The EOs were obtained by hydrodistillation and their chemical compositions analyzed by gas chromatography coupled to mass spectrometry and flame ionization detectors. The major compound identified in all EO samples was 1,8-cineole with amounts ranged from 14.4% (January, 6 am) to 33.0% (July, 3 pm). The highest average of 1,8-cineole was obtained during circadian study of the dry season (25.5% ± 5.8%) and the lowest during the circadian study of the rainy season (15.6% ± 1.5%). The multivariate analysis grouped the samples into 2 different groups: Group I characterized by the lowest amounts of 1,8-cineole (16.0%-18.7%), and Group II characterized by a higher content of 1,8-cineole (24.0%-33.0%). The oil yield and chemical composition did not show relationship with climate parameters (solar radiation, humidity, and temperature). Therefore, there was only quantitative variability in the EOs compositions during the circadian rhythm evaluated on dry and rainy seasons.

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On the genetic relationship and clasaification of Meteorites

Mineralogical Magazine and Journal of the Mineralogical Society ◽

10.1180/minmag.1916.018.83.04 ◽

1916 ◽

Vol 18 (83) ◽

pp. 26-44 ◽

Cited By ~ 76

Author(s):

G. T. Prior

Keyword(s):

Chemical Composition ◽

Genetic Relationship ◽

Close Similarity ◽

Chemical Compositions ◽

Nickel Iron

In a previous paper attention was drawn to the close similarity in mineral and chemical composition of chondritic meteoric stones. In the case of about forty chondrites it was shown that, apart from variations in the amount of nickel-iron, not only are the constituent minerals present in very similar amounts, but their chemical compositions vary to no very great extent. In that paper sufficient importance was not attached to the variations in the amount of nickel-iron.

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Chemical Compositions of the Bark Essential Oils of Croton Monteverdensis and Croton Niveus from Monteverde, Costa Rica

Natural Product Communications ◽

10.1177/1934578x0600100710 ◽

2006 ◽

Vol 1 (7) ◽

pp. 1934578X0600100 ◽

Cited By ~ 6

Author(s):

William N. Setzer

Keyword(s):

Costa Rica ◽

Chemical Composition ◽

Essential Oil ◽

Essential Oils ◽

Chemical Compositions ◽

Medicinal Uses ◽

Oil Components

The essential oils of the barks of Croton monteverdensis Huft and C. niveus Jacq. (Euphorbiaceae) from Monteverde, Costa Rica, were isolated by hydrodistillation in yields of 0.03% and 0.10%, respectively. The chemical composition of the oils was determined by GC–MS. The most abundant essential oil components of C. monteverdensis were α-pinene (17.1%), β-pinene (10.5%), and linalool (8.3%), while C. niveus bark oil was made up largely of α-pinene (14.4%), 1,8-cineole (11.6%), and borneol (8.5%). The major components account for the fragrances and are consistent with the traditional medicinal uses of these plants.

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Sludge chemical composition changes under uni-directional freezing

Water Science & Technology ◽

10.2166/wst.1996.0472 ◽

1996 ◽

Vol 34 (3-4) ◽

pp. 525-531 ◽

Cited By ~ 7

Author(s):

W. T. Huang ◽

I. L. Chang ◽

D. J. Lee ◽

S. G. Hong

Keyword(s):

Chemical Composition ◽

Activated Sludge ◽

High Speed ◽

Ftir Spectra ◽

Ice Formation ◽

Waste Activated Sludge ◽

Chemical Compositions ◽

Low Speed ◽

Directional Freezing ◽

Composition Changes

The chemical compositions changes for waste activated sludge at different freezing speeds were analyzed via FTIR spectra. With a high speed of freezing, the chemical compositions are little influenced by the action of ice formation, which with a low speed of freezing, the chemical compositions are largely affected. The prerequisite for sufficient dewaterability improvement is found as the global floc migration owing to the ice front formation, which releases some ECPs (basically cellulose) from the sludge and after the resulting cake structure ultimately.

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