Search results for "Solvent extraction"
showing 10 items of 37 documents
Occurrence and daily intake of ochratoxin A of organic and non-organic rice and rice products
2005
Abstract Ochratoxin A (OTA) was extracted from 84 rice samples and rice products by using accelerated solvent extraction (ASE) and analysed with liquid chromatography coupled with fluorescence detection. Samples were collected from rice cultivars, local markets and supermarkets; 64 were of non-organic and 20 of organic production. 7.8% of non-organic samples had OTA levels from 4.3 to 27.3 μg/kg and in 30% of organic samples was detected the presence of this mycotoxin varying from 1.0 to 7.1 μg/kg. OTA presence was confirmed by methyl-ester derivatization. Rice and rice products labelled with denomination of origin (DO) were not detected OTA due to the fact that its production has implement…
Representativeness of Extracts of Offset Paper Packaging and Analysis of the Main Odor-Active Compounds
2004
Packagings often carry odors due to the support and printing inks. The aim of the investigation was to define a representative solvent-free extract of paper-based packaging materials printed by the offset process, for the identification of the odor-causing volatile compounds. Static headspace and solid-phase microextraction were the two applied extraction methods. Representativeness tests showed that the odor of the PDMS fiber extract gave satisfying odor similarities with the original packaging. The sample incubation was performed at 40 degrees C for 30 min, whereas the extraction time was 3 min at 40 degrees C. Extracts of both the nonprinted and printed papers of different batches were a…
Euphosantianane A–D: Antiproliferative Premyrsinane Diterpenoids from the Endemic Egyptian Plant Euphorbia Sanctae-Catharinae
2018
Euphorbia species are rich in diterpenes. A solvent extraction of Euphorbia sanctae-catharinae, a species indigenous to the Southern Sinai of Egypt, afforded several premyrsinane diterpenoids (1&ndash
Extraction of Phenolic Compounds from Fresh Apple Pomace by Different Non-Conventional Techniques
2021
Red Delicious apple pomace was produced at laboratory scale with a domestic blender and different non-conventional extraction techniques were performed to isolate phenolic compounds, such as ultrasound-assisted extraction (UAE), ultraturrax extraction (UTE), accelerated solvent extraction (ASE) and pulsed electric field (PEF) extraction pre-treatment. Total phenolic content (TPC) was determined by Folin–Ciocalteu assay. Phloridzin, the main phenolic compound in apples, was determined by chromatographic analysis Q-TOF-LC/MS. The results obtained with these techniques were compared in order to identify the most efficient method to recover polyphenols. The highest value of TPC (1062.92 ± 59.80…
Liquid-scintillation detection of preseparated 257Rf with the SISAK-system
2005
Abstract The fast liquid–liquid extraction system SISAK with continuous liquid scintillation detection was coupled to the Berkeley Gas-filled Separator to enable studies of the chemical properties of α -decaying transactinide elements. The preseparated transactinide 257Rf (4.7 s), was transported via a He/KCl-jet directly into the scintillation solution. This permitted the first unambiguous detection of transactinide atoms by the means of the α -liquid scintillation detectors of the SISAK-system. During the experiment, 89 257Rf atoms were observed. The type of events observed correspond well with the expectations based on half-lives, decay branches and transport- and hold-up times. The succ…
Antioxidant phenolic compounds recovery from Mangifera indica L. by-products by supercritical antisolvent extraction
2015
Abstract Supercritical Antisolvent Extraction (SAE) was used in the recovery of antioxidant compounds from mango by-products. The antioxidant extract was obtained by solid–liquid extraction using aqueous acetone (80% v/v) and subsequent adsorption/desorption in C18 cartridge. Recovery of antioxidants was performed by SAE using SC-CO 2 as antisolvent. The temperature and pressure parameters were varied in the range 35–45 °C and 8–15 MPa. The SAE process allowed the recovery of about 90% of the initial phenolic compounds, the best recovery was obtained at 40 °C and 10 MPa and the main compounds were mangiferin, isomangiferin, quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-x…
Anomalous solvent extraction behavior of astatine
1997
We studied the solvent extraction behavior of astatine and found the anomalous behavior of this element similar to radioiodine. Astatine was extracted into CS2 from acidic solution over a wide range of carrier iodine concentration. The distribution ratios of astatine were determined by measuring the γ-ray from 210 At with a Nal(TI) detector. A drastic change was observed around at 10−4 mol/l as in the case of 131 I. This tendency is well explained by the kinematics of the chemical reactions concemed.
Beeswax cleaning by solvent extraction of pesticides
2018
We set out to test if the methodology used to clean sheep wool wax (Lanolin) from pesticides could be used to clean beeswax as well. We first made an aggregate sample of brood comb wax from three different US beekeepers. Sub-samples of these aggregate wax samples were analyzed for pesticide contamination. The remaining wax, was then dissolved into hexane solution and run through four N, N-Dimethylformamide (DMF) washes. During these extractions, the pesticides partitioned into the DMF, and so were removed from the beeswax. Following the solvent extractions, the beeswax was tested again for pesticides. An average of 95% of the pesticide contamination was removed by the chemical wash procedur…
Purification of recovered phosphoric acid by extracting aluminium with di-2-ethylhexyl phosphoric acid
2021
AbstractThe extraction of aluminium from dilute phosphoric acid with di-2-ethylhexyl phosphoric acid (DEHPA) was optimized using response surface methodology. The optimization was based on the experimental three-level central composite face-centred design (CCF) and was conducted on real-life samples. The three variables included were pH, extractant concentration and aqueous to organic phase ratio (AO). Under the optimized conditions (pH 2.5, 0.6 M DEHPA and AO ratio 1:2), extraction efficiency of 99% for aluminium in four extraction stages is achieved. The purified phosphoric acid solution can then be utilized by the fertilizing industry. Stripping tests for organic phase loaded with alumin…
Influence of Temperature, Solvent and pH on the Selective Extraction of Phenolic Compounds from Tiger Nuts by-Products: Triple-TOF-LC-MS-MS Character…
2019
The aim of this study was to assess the effect of temperature, solvent (hydroethanolic mixtures) and pH on the recovery of individual phenolic compounds from &ldquo