Search results for "COMPOSITION"

Tannin analysis of chestnut bark samples (Castanea sativa Mill.) by HPLC-DAD-MS.

2014

In the present investigation, an HPLC-DAD/ESI-MS method for the complete analysis of tannins and other phenolic compounds of different commercial chestnut bark samples was developed. A total of seven compounds (vescalin, castalin, gallic acid, vescalagin, 1-O-galloyl castalagin, castalagin and ellagic acid) were separated and quantified, being 1-O-galloyl castalagin tentatively identified and found for the first time in chestnut bark samples. Thus, this method provided information regarding the composition and quality of chestnut bark samples, which is required since these samples are commercialised due to their biochemical properties as ingredients of food supplements.

Photocatalytic Properties of Cement-Based Plasters and Paints Containing Mineral Pigments

2010

Innovative cement-based premix products for surface coating of buildings that possess photocatalytic activity arouse great interest because of the results they can achieve in reducting air pollution and maintaining aesthetics. This photoactivity is induced by a photocatalyst, titanium dioxide, that can accelerate the oxidation processes of air pollutants, particularly nitrogen oxides and volatile organic compounds, which are mainly produced by incomplete combustion of fuel and are present in urban environments through the exhaust gases of motor vehicles. Surfaces that are coated with these products acquire a self-cleaning characteristic (maintenance of original color) because the decomposi…

Chemical composition of the essential oil of the local endemics Centaurea davidovii and C. parilica (Asteraceae, sect. Lepteranthus) from Bulgaria

2014

In the present study the chemical compositions of the essential oils from aerial parts of Centaurea davidovii Urum. and C. parilica Stoj. & Stef., both endemic to Bulgaria, were evaluated by GC and GC-MS. The main components of C. davidovii were β-eudesmol (13.9%), spathulenol (13.3%), caryophyllene oxide (10.1%) and ( Z)-phytol (5.4%). The main components of C parilica were hexadecanoic acid (39.2%), ( Z, Z)-9,12-octadecadienoic acid (11.9%), caryophyllene oxide (6.8%) and spathulenol (6.6%). In order to compare the essential oils composition of these taxa and of related species a PCA analysis was carried out.

Validated fast procedure for trace element determination in basil powder

2011

Abstract An inductively coupled plasma optical emission spectroscopic (ICP-OES) method has been developed and fully validated for trace element determination in basil samples. The method involves the previous sample digestion, under pressure, with a mixture of HNO 3 , HCl and H 2 O 2 inside a microwave oven, 42 elements were studied and 33 elements (Al, As, Ba, Ca, Cr, Co, Cu, Fe, Pb, Li, Mg, Mn, Mo, Ni, K, Se, Na, Sr, Tl, Ti, V, Zn, Sc, Y, La, Ce, Nd, Tb, Ho, Er, Tm, Yb, Lu) were determined quantitatively in basil leaves obtained from Morocco and Spain. The method provided recovery percentages from 89% to 113% for spiked concentrations at mg kg −1 and μg kg −1 . Accurate results were found…

Chara hispida beds as a sink of nitrogen: Evidence from growth, nitrogen uptake and decomposition

2007

8 pages, and tables stadistics, and figures.

Amiable composition. Principes directeurs du procès, Article 9 du NCPC, Application, Pouvoir d'équité, Renversement de la charge de la preuve, Princi…

1992

International audience; (Civ. 2e, 28 févr. 1990, Bull. civ. II, n° 43, p. 24, Société Chantiers modernes)

NMR chemical shift computations at second-order Møller-Plesset perturbation theory using gauge-including atomic orbitals and Cholesky-decomposed two-…

2021

We report on a formulation and implementation of a scheme to compute NMR shieldings at second-order Moller-Plesset (MP2) perturbation theory using gauge-including atomic orbitals (GIAOs) to ensure gauge-origin independence and Cholesky decomposition (CD) to handle unperturbed as well as perturbed two-electron integrals. We investigate the accuracy of the CD for the derivatives of the two-electron integrals with respect to an external magnetic field as well as for the computed NMR shieldings, before we illustrate the applicability of our CD based GIAO-MP2 scheme in calculations involving up to about one hundred atoms and more than one thousand basis functions.

On the chemical composition and nutritional value of Pleurotus taxa growing on Umbelliferous plants (Apiaceae)

2005

Unpublished data on the chemical composition and nutritional value of Pleurotus mushrooms, growing on Umbelliferous plants (Apiaceae), are here reported. Cultivated basidiomata of four different Pleurotus taxa were analyzed in order to evaluate the composition in lipids, sugars, nitrogen, water, vitamins, ashes, and energetic values. The results showed that Pleurotus mushrooms are suitable in every type of diet thanks to their low caloric content, gastronomic value, vitamins, and mineral salt contents. The presence of a high content of vitamin B(12) and riboflavin in Pleurotus nebrodensis is noteworthy.

ChemInform Abstract: Au+ n-Induced Decomposition of N2O.

2010

Toward Three-Dimensional Chemical Imaging of Ternary Cu–Sn–Pb Alloys Using Femtosecond Laser Ablation/Ionization Mass Spectrometry

2017

Femtosecond laser ablation/ionization mass spectrometry (LIMS) has been applied to probe the spatial element composition of three ternary Cu-Sn-Pb model bronze alloys (lead bronzes: CuSn10Pb10, CuSn7Pb15, and CuSn5Pb20), which were recently identified as high-performance cathode materials in the context of electro-organic synthesis (dehalogenation, deoxygenation) of pharmaceutically relevant building blocks. The quantitative and spatially resolved element analysis of such cathode materials will help in understanding the observed profound differences in their electrochemical reactivity and stability. For that purpose, we developed a measurement procedure using the LIMS technique which allows…