Oxidation of triamantane by sulphuric acid

1983 ◽  
Vol 48 (4) ◽  
pp. 1074-1076 ◽  
Author(s):  
Zdeněk Kafka ◽  
Luděk Vodička ◽  
Milan Hájek
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Sulphuric Acid ◽  
Functional Groups ◽  
Reaction Products ◽  
Reaction Conditions ◽  
Nmr Spectrometry ◽  
C Nmr

The oxidation of triamantane by sulphuric acid was studied in various reaction conditions. 8-Triamantanone, 8,16-triamantanedione, and 15-hydroxy-8-triamantanone were isolated and identified as reaction products. The reaction was monitored and the purity of the compounds prepared was checked by gas chromatography and mass spectrometry, the position of the functional groups was determined by 13C NMR spectrometry.

scholarly journals Identification of Aroma Differences in Refined and Whole Grain Extruded Maize Puffs

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2261 ◽  
Author(s):  
Kenneth Smith ◽  
Devin G. Peterson
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Descriptive Analysis ◽  
Analytical Data ◽  
Gas Chromatography Mass Spectrometry ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Whole Grain ◽  
Whole Grain Flour

Differences in the aroma profiles of extruded maize puffs made from refined grain and whole grain flour were investigated. Gas chromatography/mass spectrometry/olfactometry (GC/MS/O) analysis reported 13 aroma compounds with a flavor dilution (FD) value ≥16. Quantitative analysis identified eight compounds as statistically different, of which seven compounds were higher in concentration in the whole grain sample. Sensory recombination and descriptive analysis further supported the analytical data, with higher mean aroma intensities for cooked, corn chip, roasted, and toasted attributes for the whole grain sample. Generally, the compounds responsible for perceived differences in whole grain maize extruded puffs were associated with increased levels of Maillard reaction products, such as 2-ethyl-3,5-dimethylpyrazine and 2-acetyl-2-thiazoline.

scholarly journals Wild Thymbra Capitata from Western Rif (Morocco): Essential Oil Composition, Chemical Homogeneity and Yield Variability

2013 ◽  
Vol 8 (8) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Khadija Bakhy ◽  
Ouafae Benlhabib ◽  
Chaouki Al Faiz ◽  
Ange Bighelli ◽  
Joseph Casanova ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Retention Indices ◽  
Essential Oil Composition ◽  
Gas Chromatography Mass Spectrometry ◽  
Yield Variability ◽  
Oil Composition ◽  
Chemical Homogeneity ◽  
Quantitative Characteristics ◽  
C Nmr

Essential oils (EO, 15 collective samples and 47 individual samples) of Thymbra capitata collected from Moroccan Western Rif were analyzed using gas chromatography (GC) in combination with retention indices (RI), gas chromatography-mass spectrometry (GC-SM) and 13C NMR spectroscopy. Twenty components were identified. Carvacrol (68.2%–85.9 %) was by far the major component of all the samples, while the content of thymol (0.1-0.3%) was very low. Other components present in appreciable amounts were γ-terpinene (up to 8.9%), p-cymene (up to 7.1%), linalool (up to 4.4%) and ( E)- β-caryophyllene (up to 4.1%). In contrast, the yield of EO varied drastically from sample to sample (0.5–3.7%). No correlation could be established between yield of EO and altitude, pH, chemical composition and granularity of the soil. Cultivation under controlled conditions is suggested to improve the quantitative characteristics of carvacrol-rich Moroccan T. capitata.

Hydrothermal Liquefaction of Wheat Straws for Bio-Oil and Related Analyses

2011 ◽  
Vol 347-353 ◽  
pp. 2419-2422 ◽  
Author(s):  
Hui Wang ◽  
Xiao Juan Liu ◽  
Yan Xing Liu ◽  
Peng Chen ◽  
Jian Sun
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Fourier Transform ◽  
Hydrothermal Liquefaction ◽  
Gas Chromatography Mass Spectrometry ◽  
Reaction Conditions ◽  
Heating Value ◽  
Bio Oil ◽  
The Fourier Transform ◽  
Optimal Reaction

The liquefaction of wheat straws in sub-critical water to obtain bio-oil was investigated in this paper. We observed that the reaction temperature (300-374 °C) and reaction time (1-15 min) played important roles in the yield of bio-oil and found the optimal reaction conditions (340 °C, 5 min). The bio-oil was analyzed by elemental analysis, the Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Results indicated that the heating value of bio-oil product was 32-38 MJ/kg, higher than that of the bio-oil obtained from microalgae, and the product was composed of ketones, phenol and its derivatives, aromatics and small amount of aldehydes and ethers.

scholarly journals A Facile and Catalyst-free Synthesis of Hexahydroacridine-1,8(2H,5H )-dione and Octahydroacridin-10(1H )-yl)thiourea Derivatives: Inter- and Intramolecular Aza-Michael addition

2020 ◽  
Vol 26 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Nader Noroozi Pesyan ◽  
Narmin Akhteh ◽  
Hana Batmani ◽  
Barış Anıl ◽  
Ertan Şahin
Keyword(s):  
Hydroxylamine Hydrochloride ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
Thiourea Derivatives ◽  
H Nmr ◽  
Nmr Spectrometry ◽  
The One ◽  
Convenient Technique ◽  
C Nmr

AbstractAn easy and convenient technique for the one-pot synthesis of novel compounds of hexahydroacridine-1,8(2H,5H)-dione and octahydroacridin-10(1H)-yl) thiourea derivatives has been developed by the reaction of the octahydro-1H-xanthenes with hydroxylamine hydrochloride and thiosemicarbazide in ethylene glycol, which is a green solvent, under mild reaction conditions. IR, 1H NMR, 13C NMR spectrometry, and X-ray diffraction analysis were used to identify the structures of these compounds.

ANALYSIS OF SOLVOLYZABLE STEROIDS IN HUMAN PLASMA BY COMBINED GAS CHROMATOGRAPHY - MASS SPECTROMETRY

1968 ◽  
Vol 57 (2) ◽  
pp. 247-260 ◽  
Author(s):  
J. Sjövall ◽  
R. Vihko
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Human Plasma ◽  
Sulphuric Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Peripheral Plasma ◽  
Chromatography Mass Spectrometry ◽  
Steroid Conjugates

ABSTRACT Solvolyzable steroids in human peripheral plasma were separated by chromatography on Sephadex LH-20 into two fractions having the elution volumes of mono- and disulphates, respectively. The steroid conjugates in the latter fraction had the mobility of steroid disulphates on TLC. After solvolysis in ethyl acetate acidified with sulphuric acid the steroids were analyzed by gas chromatography and combined gas chromatography - mass spectrometry. Cholesterol, dehydroepiandrosterone, androsterone, epiandrosterone, aetiocholanolone, pregnenolone, pregn-5-ene-3β,20α-diol, androst-5-ene-3β,17β-diol, androst-5-ene-3β,17α-diol and an androstanediol, most probably 5α-androstane-3α,17β-diol were found in the monosulphate fraction. Androst-5-ene-3β,17β-diol, androst-5-ene-3β,17α-diol and pregn-5-ene-3β,20α-diol were found in the disulphate fraction. The ratio of C19 to C21 diols was higher in the disulphate than in the monosulphate fraction.

scholarly journals A switchable [2]rotaxane with two active alkenyl groups

2018 ◽  
Vol 14 ◽  
pp. 2074-2081 ◽  
Author(s):  
Xiu-Li Zheng ◽  
Rong-Rong Tao ◽  
Rui-Rui Gu ◽  
Wen-Zhi Wang ◽  
Da-Hui Qu
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Functional Groups ◽  
Stimuli Responsive ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Recognition Sites ◽  
Acid And Base ◽  
C Nmr

A novel functional [2]rotaxane containing two alkenyl bonds was designed, synthesized and characterized by 1H, 13C NMR spectroscopy and HRESI mass spectrometry. The introduction of alkenyl bonds endowed the [2]rotaxane a fascinating ability to react with versatile functional groups such as alkenyl and thiol functional groups. The reversible shuttling movement of the macrocycle between two different recognition sites on the molecular thread can be driven by external acid and base. This kind of rotaxane bearing functional groups provides a powerful platform for preparing stimuli-responsive polymers.

Laser-induced addition of hydrogen fluoride to unsaturated molecules: the HF + CH2CF2 system

1984 ◽  
Vol 62 (11) ◽  
pp. 2302-2309 ◽  
Author(s):  
Walter H. Beck ◽  
George Burns
Keyword(s):  
Mass Spectrometry ◽  
Information Theory ◽  
Gas Chromatography ◽  
Gas Phase ◽  
Hydrogen Fluoride ◽  
Vibrational Level ◽  
Upper Bound ◽  
Addition Reactions ◽  
Reaction Products ◽  
Addition Rate

Although certain classes of reactions are known to occur via 4-centre transition states, there has been no irrefutable proof that in the gas phase addition reactions also proceed via a 4-centre concerted process. Results of recent information theory calculations on the HF(υ) + CH2CF2 system indicate that it should be possible to observe reaction products for HF(υ = 5). Results are presented here on experiments attempting to achieve laser-induced 4-centre addition of HF to several unsaturated molecules (C2H2, C2H4, C4H6, CH2CF2, and CF2CClF). A mixture of HF and co-reactant was irradiated by a dye-laser tuned photo-acoustically to the fifth vibrational level of HF, and the resulting mixture was analysed by gas chromatography and mass spectrometry. There was no evidence of any laser-induced products. An upper bound was deduced for the HF + CH2CF2 addition rate constant at 610 K: [Formula: see text].

scholarly journals Evaluation of sulfide catalysts performance in hydrotreating of oil fractions using comprehensive gas chromatography time-of-flight mass spectrometry

2020 ◽  
Vol 92 (6) ◽  
pp. 941-948
Author(s):  
Eduard Karakhanov ◽  
Anton Maximov ◽  
Leonid Kulikov ◽  
Daria Makeeva ◽  
Maria Kalinina ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Time Of Flight ◽  
Light Cycle ◽  
Sulfide Catalysts ◽  
Reaction Products ◽  
Light Cycle Oil ◽  
Flight Mass Spectrometry ◽  
Porous Aromatic Frameworks ◽  
Oil Fractions

AbstractIn this study, two oil fractions – straight-run diesel and light cycle oil (LCO) – and the products of their hydrotreatment with sulfide catalysts, synthesized in the pores of porous aromatic frameworks, were analyzed by comprehensive two-dimensional gas chromatography (GC) with time of flight mass spectrometry (GC × GC–TOFMS). Effective separation of numerous compounds in the analyzed multicomponent mixtures and high resolution of mass spectra of reaction products made it possible to study the features of the activity of sulfide catalysts.

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