scholarly journals Quantitative Determination of Chemical Composition of Multinary III/V Semiconductors With Sublattice Resolution Using Aberration Corrected HAADF-STEM

2015 ◽  
Vol 21 (S3) ◽  
pp. 2081-2082
Author(s):  
Andreas Beyer ◽  
Nikolai Knaub ◽  
Kerstin Volz
Keyword(s):  
Chemical Composition ◽  
Quantitative Determination ◽  
Aberration Corrected

scholarly journals Composition of Essential Oils in Turmeric Rhizome

2016 ◽  
Vol 16 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Laxmi Devkota ◽  
Meena Rajbhandari
Keyword(s):  
Chemical Composition ◽  
Essential Oil ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Essential Oils ◽  
Colorimetric Method ◽  
Acetone Extract ◽  
Caryophyllene Oxide ◽  
Finger Printing

Turmeric has been recognized as a pharmaceutical crop. It is valuable primarily for essential oil and curcumin content. Chemical composition of the essential oils obtained from the rhizome of turmeric was determined by GC/MS technique. More than 75 compounds were detected and 67 of them were identified. They accounted for 98.59% of essential oil. The essential oil contained 15 monoterpenes (5.58%), 43 sesquiterpenes (84.37%) and 10 nonterpenic components (8.64%). The major constituents were ß-turmeron, a-turmeron, Epi-a-patschutene, ß-sesquiphellandrene, 1,4-dimethyl-2-isobutylbenzene, (±)-dihydro-ar-turmerone, zingiberene, E-a-atlantone and (-)-caryophyllene oxide. Thin layer chromatographic finger printing and quantitative determination of phenolics in acetone extract of commercially available turmeric samples were carried out using Folin-Ciocalteu colorimetric method. Gallic acid was used as the standard for the estimation of phenolics. All the investigated turmeric extracts contained relatively high amount of phenolics.Nepal Journal of Science and Technology Vol. 16, No.1 (2015) pp. 87-94

scholarly journals Qualitative and quantitative determination of water in airborne particulate matter

2012 ◽  
Vol 12 (10) ◽  
pp. 27367-27393
Author(s):  
S. Canepari ◽  
C. Farao ◽  
E. Marconi ◽  
C. Giovannelli ◽  
C. Perrino
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Quantitative Determination ◽  
Inorganic Ions ◽  
Airborne Particulate Matter ◽  
Dicarboxylic Acids ◽  
Atmospheric Particulate Matter ◽  
Simple Method ◽  
Field Samples

Abstract. This paper describes the optimization and validation of a new simple method for the quantitative determination of water in atmospheric particulate matter (PM). The analyses are performed by using a coulometric Karl-Fisher system equipped with a controlled heating device; different water contributions are separated by the application of an optimized thermal ramp (three heating steps: 50–120 °C, 120–180 °C, 180–250 °C). The analytical performance of the method was verified by using standard materials containing 5.55% and 1% by weight of water. The recovery was greater than 95%; the detection limit was about 20 μg. The method was then applied to NIST reference materials (NIST1649a, urban particulate matter) and to real PM10 samples collected in different geographical areas. In all cases the repeatability was satisfactory (10–15%). When analyzing the reference material, the separation of four different types of water was obtained. In real PM10 samples the amount of water and its thermal profile differed as a function of the chemical composition of the dust. Mass percentages of 3–4% of water were obtained in most samples, but values up to about 15% were reached in areas where the chemical composition of PM is dominated by secondary inorganic ions and organic matter. High percentages of water were also observed in areas where PM is characterized by the presence of desert dust. A possible identification of the quality of water released from the samples was tried by applying the method to some hygroscopic compounds that are likely contained in PM (pure SiO2, Al2O3, ammonium salts, carbohydrates and dicarboxylic acids) and by comparing the results with those obtained from field samples.

scholarly journals NMR-Spectroscopy Determination of Fragmentary Composition of Bitumen and its Components

2018 ◽  
Vol 20 (2) ◽  
pp. 153 ◽  
Author(s):  
B. Teltayev ◽  
T. Seilkhanov
Keyword(s):  
Chemical Composition ◽  
Nmr Spectroscopy ◽  
Quantitative Determination ◽  
Adsorption Chromatography ◽  
Spectroscopy Method ◽  
Chromatography Method ◽  
Group Chemical ◽  
Methylene Group ◽  
Method Group

This paper represents and discusses the results of quantitative determination for fragmentary composition of road bitumen of grade BND 100/130 and its components (asphaltenes, resins and oils) by NMR spectroscopy method. Group chemical composition of the bitumen has been determined by adsorption chromatography method. It has been identified that the bitumen and its components consist only of aromatic and aliphatic protons, which account for 2.4‒10.2% and 9.8‒97.6% respectively. Availability of olefinic elements in them has not been identified. The most part (79‒81%) of nuclei of carbon atoms relates to quaternary carbon atoms of saturated compounds. Primary carbon atoms at methylene group (CH2) are contained in the least quantity: bitumen ‒ 1.32%; asphaltenes – 0.6%; resins – 3.24% and oils – 2.11%. Primary carbon atoms, linked with CH-group or aromatic nucleus, occupy an intermediate position and are contained in the quantity of 17‒20%.

scholarly journals Chromato-mass spectrometric identification of asymmetric dimethylhydrazine and its derivatives in environmental objects and biological media in the population residing near the fall areas of separated rocket vehicles parts

2020 ◽  
Vol 99 (8) ◽  
pp. 773-779
Author(s):  
Vadim B. Alekseev ◽  
Tatyana S. Ulanova ◽  
Tatyana V. Nurislamova ◽  
Nina A. Popova ◽  
Olga A. Maltseva
Keyword(s):  
Mass Spectrometry ◽  
Drinking Water ◽  
Chemical Composition ◽  
Quantitative Determination ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Blood Samples ◽  
The Republic ◽  
Snow Samples

Introduction. The issue of presence/absence of the consequences of technogenic space and rocket activity over the long period is on the agenda of the professional, social, and political communities, especially in regions were the certain territories have been appointed as the fall areas for the separated rocket vehicles parts, including the Republic of Altai.Aim of study. Identification of the chemical composition of snow samples, drinking water, and blood in the population residing in the fall areas of the separated rocket vehicle parts in the Republic of Altai.Material and methods. Identification of the chemical composition has been performed along with the quantitative determination of the content of N-nitrosamines in blood samples (n=50) in n the population who constantly live near to the fall areas of the separated rocket vehicles, as well snow samples (n=7), and drinking water (n=9). The samples were examined by a hybrid method using an Agilent gas chromatograph with a quadrupole mass spectrometric detector. In order to decrypt the results of the mass spectrometric analysis, we used the NIST Mass Spectrometry Data Library 08.L, WILEY275.L, PMW_TOX2.L., libraries of the United States Environmental Protection Agency, narcotic, herbal, toxic and contaminated substances. The quantitative determination of N-nitrosamines in the blood samples was performed by the method of chromatography-mass spectrometry.Results. During the library search, 94% of the studied blood samples in the population registered substances that can be identified as unsymmetric dimethylhydrazine and 6% of the samples contain its decomposition product N-nitrosodimethylamine. However, the probability of categorizing these impurities to the desired substances was of 4-26%. In the blood samples of residents in whom there were identified asymmetric dimethylhydrazine and N-NDMA by quantitative chromatography-mass spectrometric analysis, the tag (Alt+2) N-nitrosodimethylamine and N-nitrosodiethylamine was found in the concentration range of 0.00095-0.346 mg/dm3. In 100% of the studied drinking water samples, residual amounts of asymmetric dimethylhydrazine were identified with a low probability of matching the library mass spectrum of 12-33%.Conclusion. The conducted chromatography-mass spectrometry studies of snow samples, samples of the water, and blood of the population living near to the fall area of the separated rocket vehicle parts in the Republic of Altai allowed establishing the signs of residual quantities of dimethylhydrazine and N-nitrozodimethylamine.

scholarly journals LIPIDS 0F SEEDS MEDICAGO SATIVA, AMARANTHUS CRUENTUS AND AMARANTHUS RETROFLEXUS, GROWING IN GEORGIA

2021 ◽  
Author(s):  
Durmishkhan Turabelidze ◽  
Tsitsana Sulakvelidze ◽  
Bela Kikalishvili ◽  
Manana Malania
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Quantitative Determination ◽  
Free Fatty Acids ◽  
Medicago Sativa ◽  
Amaranthus Retroflexus ◽  
Amaranthus Cruentus ◽  
Qualitative And Quantitative ◽  
Neutral And Polar Lipids

There is studied chemical composition of neutral and polar lipids of the seeds of: Medicago sativa, Amaranlhus cmentus and Amaranthus retroflexus growing in Georgia. The composition of free fatty acids was determined with help GLC and HPLC. There is determined class and fatty acidal composition of them, qualitative and quantitative determination of phospholipids is carried. There is elaborated various medicinal forms from Medicago sativat.

scholarly journals The quantitative determination of products of isothermal desintegration of austenite

2006 ◽  
Vol 54 (1) ◽  
pp. 127-134
Author(s):  
Michal Učeň ◽  
Josef Filípek
Keyword(s):  
Chemical Composition ◽  
Quantitative Determination ◽  
Constitution Diagram ◽  
Structural Diagram

With the help of a constitution diagram Fe – Fe3C, a diagram TTT and vertical structural diagram of the authors´ own construction it is determined that the relative amount of products in steel occurs in any temperature of isothermal disintegration of austenite. Making use of camouflage it is enabled to set bouth structural and phasic composition of alloy at the same time. In case of use of appropriate animating software (e.c. Macromedia Flash) it is possible to practise this quantification on steel of any chemical composition.

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