Search results for "Extraction"
showing 10 items of 2072 documents
Extraction of lanthanides and actinides by a magnetically assisted chemical separation technique based on CMPO-calix[4]arenes
2001
A novel particulate system carrying CMPO ligands pre-organised on a calixarene scaffold has been synthesised and demonstrated to extract Eu3+, Am3+ and Ce3+ at high efficiency from simulated nuclear waste streams.
ChemInform Abstract: New Eudesmane Derivatives from Artemisia tournefortiana
1990
Extraction of the aerial parts of Artemisia tournefortiana Reichb. yields a new cis-eudesmanolide 4 and three new eudesmane acids 7, 8, and 10, together with several known compounds. Their structures were deduced by spectroscopic and chemical methods.
Conventional, non-conventional extraction techniques and new strategies for the recovery of bioactive compounds from plant material for human nutriti…
2019
Considering a large number of variations in the chemical structures of bioactive compounds (BACs) that are valuable to humans and a large number of their sources, it is necessary to build a standard and integrated extraction and analytical approaches for obtaining these compounds. From this perspective, the main purpose of this Special Issue of Food Research International was to publish research related to the extractions with data about isolation of BACs from plant matrices for human nutrition. This Special Issue includes both, conventional and innovative extraction techniques, highlighting their characteristics and advantages in relation to the target matrix. Many of presented works conta…
Application of fast solvent extraction processes to studies of exotic nuclides
1998
Fast solvent extraction is a chemical separation method, which can be applied to study exotic nuclides. Since about 1970 the SISAK technique, which is an on-line method based on multi-stage solvent extraction separations, has been successfully used to investigate the nuclear properties of β-decaying nuclides with half-lives down to about one second. During the last decade it has become possible to produce transactinide elements in high enough yields to investigate their chemical properties on a one-atom-at-a-time scale. For this purpose it was necessary to improve and change the detection part of the SISAK system in order to be capable to detect spontaneously fissioning and α-decaying nucli…
Extraction of the fluoride-, chloride- and bromide complexes of the elements Nb, Ta, Pa, and 105 into aliphatic amines
1998
Abstract Previous studies of the halide complex formation of element 105 in HCl–HF mixtures and extractions into triisooctyl amine (TIOA) have been performed with the Automated Rapid Chemistry Apparatus, ARCA II. Element 105 was shown to be absorbed on the column from 12 M HCl–0.02 M HF together with its lighter homologues Nb, Ta and the pseudohomologue Pa. In elutions with 10 M HCl–0.025 M HF, 4 M HCl–0.02 M HF, and 0.5 M HCl–0.01 M HF, the extraction sequence Ta>Nb>105>Pa was observed and element 105 behaved very differently from its closest homologue Ta. As it is not possible within reasonable effort to model the many presumably mixed fluoride–chloride complexes involved in these studies…
Soil Carbon, Nitrogen and Phosphorus Dynamics as Affected by Solarization Alone or Combined with Organic Amendment
2006
Soil solarization, alone or combined with organic amendment, is an increasingly attractive approach for managing soil-borne plant pathogens in agricultural soils. Even though it consists in a relatively mild heating treatment, the increased soil temperature may strongly affect soil microbial processes and nutrients dynamics. This study aimed to investigate the impact of solarization, either with or without addition of farmyard manure, in soil dynamics of various C, N and P pools. Changes in total C, N and P contents and in some functionally-related labile pools (soil microbial biomass C and N, K2SO4-extractable C and N, basal respiration, KCl-exchangeable ammonium and nitrate, and water-sol…
Comparative cytotoxicity evaluation of eight root canal sealers
2017
Background The aim of the present study is to evaluate and compare the cytotoxic effects of eight root canal sealers (BioRoot RCS, TotalFill BC Sealer, MTA Fillapex, Sealapex, AH Plus, EasySeal, Pulp Canal Sealer, N2) on immortalized human gingival fibroblasts over a period of 24, 48 and 72 hours. Material and Methods Immortalized human gingival fibroblast-1 HGF-1 (ATCC CRL-2014) were incubated. Root canal sealers were then placed into sterile, cylindrical Teflon moulds. The extraction was made eluting the sealers in cell culture medium. Cells (1 × 104) were seeded in each well of a 96-well plate and incubated for 24 h at 37°C. Cultures were then exposed to 100 μL of the extracts medium. Th…
Chemometric extraction of analyte-specific chromatograms in on-line gradient LC-infrared spectrometry
2009
This work exploits the possibilities offered by the recently developed multivariate method named Science-Based Calibration (SBC), for the extraction of ‘analyte-specific’ chromatograms in on-line gradient reversed phase LC-infrared spectrometry (IR) in the presence of a high spectral and chromatographic overlapping between the analyte of interest, co-eluting sample matrix constituents and the mobile phase components. The SBC method uses an experimentally measured single response spectrum of the analyte of interest and representative noise to calculate an optimum regression vector (bopt(1)). Then, the bopt(1) vector is used to predict the concentration of the analyte of interest in the spect…
Determination of Olive Oil Parameters by Near Infrared Spectrometry
2010
Publisher Summary Near infrared (NIR) covers the region between 780 and 2500 nm, and based on the absorption, transmission or reflection of the light, NIR spectroscopy provides a fast and non-destructive technique which is very useful for the simultaneous determination of several compounds in the same sample. Food NIR spectra comprise broad bands corresponding to overtones and combinations of vibrational modes involving C–H, O–H, and N–H chemical bonds, providing a great amount of information which properly treated by chemometrics is useful for classification and for the quantification of many parameters. The olive oil extraction process starts in the harvesting and transport of olive fruit…
Negative pressure cavitation-microwave assisted preparation of extract of Pyrola incarnata Fisch. rich in hyperin, 2'-O-galloylhyperin and chimaphili…
2013
Abstract A novel and effective extraction method, namely negative pressure cavitation-microwave assisted extraction technique (NMAE), was developed for the preparation of extracts of Pyrola incarnata Fisch., which are rich in the main constituents hyperin, 2′-O-galloylhyperin and chimaphilin. Single factor experiments and Box–Behnken design (BBD) were combined with a response surface methodology to examine factors affecting extraction. Maximum extraction yields of hyperin, 2′-O-galloylhyperin and chimaphilin (1.339 ± 0.029, 4.831 ± 0.117 and 0.329 ± 0.011 mg/g, respectively) were achieved under the following optimised conditions: 700 W microwave power, 50 °C extraction temperature, 30:1 mL/…