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... Ninety-six hours static bioassays were made in the laboratory to determine acute toxicity of cypermethrin to five non-target freshwater organisms belonging to different taxa and niche. Susceptibility of the organisms to cypermethrin was in the order: the crustacean Diaptomus forbesi > the aquatic insect Ranatra filiformis > the freshwater carp Cyprinus carpio > the tadpole larva of the toad Bufo m ...
... A gas chromatography/ion trap mass spectrometry method was developed for analysis of organochlorine pesticides (OCPs) in coral samples, which were extracted with accelerated solvent extraction (ASE) and cleaned up on a sulfuric acid-modified silica gel column. The optimal ASE conditions were found to be 100°C and 2000 psi, with a mixture of acetone and methylene chloride (1:1, v/v). The target ana ...
... A screening for larvicidal activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for pest and vector control. In the backdrop of recent revival of interest in developing plant-based insecticides, the present study was carried out to evaluate the larvicidal properties in three medicinal plants growing abundantly in the region of Chitheri Hills, Dh ...
... Phenolic compounds were extracted from adzuki bean using 80% (v/v) aqueous acetone. Crude extract was applied onto a Sephadex LH-20 column. Fraction I, consisting of low-molecular-weight phenolics, was eluted from the column using ethanol. Fraction II, consisting of tannins, was obtained using water/acetone (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fra ...
... In this study, total phenolic contents and antioxidant activities of grape seed extracts obtained from twelve different grape seeds from common varieties grown in Turkey were determined. Grape seeds were extracted with 70% acetone and extraction yield of grape seed were calculated. The total phenolic content of grape seed extracts were determined by the Folin-Ciocalteu procedure and ranged from 33 ...
... Temperature-controlled micro thin-layer chromatography (TLC) was applied for separation and quantification studies of testosterone and its derivatives including methyltestosterone, testosterone propionate, isobutyrate, phenylpropionate, isocaproate, enanthate and caprate. Chromatographic studies were performed on silica-, octadecylsilica- and aluminum-coated plates working inside a small thermosta ...
... This investigation reports the polymerization of hexyl acrylate (HA) using atom transfer radical polymerization technique and subsequently the preparation of its di- and triblock copolymers with methyl methacrylate. Atom transfer radical polymerization of HA was investigated using different initiators and CuBr or CuCl as catalyst in combination with varying ligands, e.g., 2,2'-bipyridine and N,N,N ...
acetone; biofilters; biofiltration; chemical reactions; microbial growth
Abstract:
... In this study, the biochemical kinetic behaviors of ketone compounds in a composite bead biofilter were investigated. Both microbial growth rate k g and biochemical reaction rate k d would be inhibited at higher average inlet concentration. For the microbial growth process, the inhibitive effect was the least pronounced for acetone and the order of k g value was MEK>MIPK>acetone in the average inl ...
... Cytochrome P450 (CYP) monooxygenase activities with different category of substrates namely, alkanes, alkane derivatives, alcohols, aromatic compounds, organic solvents, and steroids were detected in the cells of Aspergillus terreus. High CYP specific activity was observed when methanol (5.6±0.017Umg-¹), acetone (7.76±0.02Umg-¹), dimethylsulphoxide (DMSO) (9.70±0.005Umg-¹), n-hexadecane (4.39±0.02 ...
... In the present study, the chemical–physical properties of bamboo pulp prepared with a sequential totally chlorine-free procedure were analyzed and compared with that of commercial wood pulp by SEM, FTIR, TGA, and X-ray. α-Cellulose content was determined to be 95%, a little less than that of commercial wood pulp. But the crystallinity of bamboo pulp is lower than wood pulp. Acetylation activity of ...
X-ray diffraction; acetone; acetonitrile; calorimeters; chloroform; composite polymers; electrolytes; films (materials); hydrogen bonding; lithium; microstructure; molecular weight; polyethylene glycol; salt concentration; scanning electron microscopes; vapors
Abstract:
... A composite polymer electrolyte film was prepared by dissolving polyethylene glycol (PEG) with different molecular weight in acetonitrile, and vapor-induced response behavior was investigated upon exposure to various chemical environments. The effect of lithium concentrations on ionic conductivity and response was discussed. The surface microporous structures and vapor sensitive conductivity of th ...
... The crystal structures of N-(3-ethylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine with waters of hydration, water and methanol, and acetone were studied by x-ray diffraction. Three conformers formed by rotation of the 3-ethylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl moiety relative to the cytisine core were detected in the studied crystal structures. Different conformations of N-(3- ...
... An online accumulation/mobilization preconcentration technique based on a dynamic pH junction technique and electrokinetic injection was employed for analysis of phenolic acids (sinapic, ferulic, coumarinic, caffeic, syringic, vanillic, and 4-hydroxybenzoic acid) in extracts from Majorana hortensis leaves. Samples were extracted by pressurized solvent extraction with acetone at 150 °C and 15 MPa. ...
acetone; acetonitrile; beers; detection limit; high performance liquid chromatography; methanol; polyphenols; quercetin; solid phase extraction; standard deviation
Abstract:
... The determination of polyphenols by spectrophotometric detection is complicated due to their low concentrations in beer. The beer samples have to be pre-concentrated before using the spectrophotometric detection for their quantification. An analytical method based on solid-phase extraction (SPE) and followed by high performance liquid chromatographic separation with diode-array detection is used f ...
... Dispersive liquid-liquid microextraction (DLLME) followed by a newly designed semi-automated in-syringe back extraction technique has been developed as an extraction methodology for the extraction of polar organic compounds prior to liquid chromatography (LC) measurement. The method is based on the formation of tiny droplets of the extractant in the sample solution using water-immiscible organic s ...
Fraxinus americana; Laurus nobilis; Pinus wallichiana; acetone; air drying; branches; chemical treatment; coatings; electric potential difference; ethanol; evaporation; growth rings; hydrogen peroxide; platinum; tracheids
Abstract:
... This paper examines the effects of 30 preparation techniques on SEMimages of pit membranes in vessels and tracheids from the two latest growth rings in twigs of Pinus wallichiana, Fraxinus americana and Laurus nobilis. Most variation observed is due to coating and treatment with chemical solutions, such as acetone, ethanol and hydrogen peroxide. The effects of chemicals appear to be associated wit ...
... Expanded bed adsorption chromatography (EBAC) is a single pass operation that has been used as primary capture step in various protein purifications. The most common problem in EBAC is often associated with successful formation of a stable fluidized bed during the absorption stage, which is critically dependent on parameters such as liquid velocity, bed height, particle (adsorbent) size and densit ...
acetone; acetonitrile; additives; atmospheric pressure; high performance liquid chromatography; ionization; mass spectrometry; methanol; solvents
Abstract:
... The high performance liquid chromatography (HPLC) separation methodology employed in the study of polyalkene additive compounds by atmospheric pressure ionization mass spectrometry (API-MS) was undertaken. Both atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) were examined. APPI (including dopant-assisted APPI) was found to be an inferior ionization t ...
... The effects of different solvent systems (methanol, ethanol, acetone, and their 50% aqueous concentrations) and extraction procedures (microwave, ultrasound, Soxhlet and maceration) on the antioxidant activity of aerial parts of Potentilla atrosanguinea were investigated by three different bioassays: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2'-diphenyl-1-pic ...
... Astaxanthin possesses higher antioxidant activity than other carotenoids and, for this and other reasons, has great commercial potential for use in the aquaculture, pharmaceutical, and food industries. The basidiomycetous yeast Xanthophyllomyces dendrorhous is one of the best natural producers of astaxanthin, but wild-type cells accumulate only a small amount of astaxanthin. In this study, we deve ...
... Peptides have recently attracted interest as building blocks for the assembly of novel functional materials including switchable surfactants, nanocoatings, hydrogels and aqueous vesicles. We expressed a beta-sheet forming peptide that has been widely studied in self-assembly processing, P₁₁-2, as a monomer, dimer, tetramer and nonamer fused to an insoluble expression partner, ketosteroid isomerase ...
... Production of acetone, butanol, ethanol, acetic acid, and butyric acid by three strains of anaerobic bacteria, which we identified as Clostridium acetobutylicum, was studied. The yield of acetone and alcohols in 6% wheat flour medium amounted to 12.7-15 g/l with butanol constituting 51.0-55.6%. Activities of these strains towards xylan, β-glucan, carboxymethylcellulose, and crystalline and amorpho ...
... The feasibility of obtaining antioxidant phenolic extracts from hazelnut by-products was investigated by long maceration at room temperature. The hard shells and defatted skins of both whole and chopped roasted hazelnut kernels were studied. Three solvent systems were employed and these included aqueous methanol, ethanol and acetone. Extraction yields as well as phenolic contents varied according ...
Yu. S. Kosenkova; M. P. Polovinka; N. I. Komarova; D. V. Korchagina; S. V. Morozov; A. I. Vyalkov; N. Yu. Kurochkina; V. A. Cheremushkina; N. F. Salakhutdinov
... Flavones 2′,5′-dimethoxyflavone, 3′-methoxy-4′,5′-methylenedioxyflavone, 3′,4′-dimethoxyflavone, 5,6,2′,3′,6′-pentamethoxyflavone, and 5,6,2′,3′,5′,6′-hexamethoxyflavone; salicylates, methyl-4-methoxysalicylate and peonol; and bisbibenzyl polyphenol riccardin C were isolated for the first time from the acetone extract of the aerial part of Primula macrocalyx Bge. The content of free and total fatt ...
... Field aging immobilizes pollutants and reduces their toxicity, but it also boosts their accumulation and holds the risk of future release. We investigated the aging of six insecticides (water solubilities: 0.33 mg L-1-completely miscible) applied five times (10-day intervals) to a tropical fruit orchard under natural weather conditions. After sequential extractions of soil samples with 0.01 M CaCl ...
model food systems; acetone; Maillard reaction products; pyrazines; pyrroles; aldehydes; amino acids; water; flavor compounds; mass spectrometry; gas chromatography; chemical structure
Abstract:
... Alkylpyrazines are a very important class of Maillard flavor compounds, but their mechanism of formation is complex and consists of different pathways. The model reaction of 20 different amino acids with 1,3-dihydroxyacetone, as a precursor of 2-oxopropanal, was studied by means of SPME-GC-MS to investigate the involvement of the amino acid side chain in the substitution pattern of the resulting p ...
... In the presented study, we describe techniques for glutathione and pigment determination in lichens used in our laboratory. Glutathione and xanthophyll cycle pigments, especially zeaxanthin, are important antioxidants protecting plants against various stresses. In our laboratory, the high light stress in lichens has been intensively studied for several years. We extract glutathione in HCl and dete ...
... Background, aim, and scope It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those si ...
... Background, aim, and scope Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. They are formed during pyrogenic and diagenetic processes and are components of petrogenic materials such as oils and coals. To identify PAH sources, several studies have employed forensic methods, which may be costly to execute. Although a large number of possible forensic methods are avail ...
... Herbals such as Cynodon dactylon, Piper longum, Phyllanthus niruri, Tridax procumbens, and Zingiber officinalis were extracted with acetone, benzene, butanol, and petroleum ether and screened against the pathogen Vibrio harveyi isolated from the infected Grouper Epinephalus tauvina. Among the different solvent extractions screening to V. harveyi, petroleum ether extracts were suppressed significan ...
... This study describes continuous monitoring of the volatile organic air pollutants, acetone and toluene, in Hsinchu Science Park (HSP) during an occurrence of inclement weather, i.e., a typhoon. Using a lab-designed sampling system coupled with a continuous automated GC-MS analysis system, a total of 53 polar and nonpolar compounds were identified and quantified. The concentration of polar compound ...
... Four commercial enzyme preparations with pectinolytic, cellulolytic and hemicellulolytic activities were tested for their ability to enhance lycopene extraction from tomato peels. Screening experiments were performed at 25 °C by subjecting the peels to a 4-h enzyme incubation followed by 1-h hexane extraction. Peclyve EP and LI were the most efficient, with an almost 20-fold increase in extraction ...
... Bridged ortho esters of 3-halopropyl carboxylic acids were prepared by esterification of 3-methyl-3-hydroxymethyloxetane with 3-bromopropionyl chloride and pyridine in dry THF, followed by rearrangement with boron trifluoroetherate, to afford 1-(2-bromoethyl)-4-methyl-2,6,7-trioxabicyclo[2,2,2]-octane. The 1-(2-iodoethyl)-4-methyl-2,6,7-trioxabicyclo[2,2,2]-octane analogue could not be prepared di ...
... To improve phenylalanine ammonia lyase (E.C.4·3·1·5-PAL) activity in recombinant Escherichia coli. Some methods for enrichment of PAL activity in recombinant E. coli JM109 were described. In an effort to create a rich enzyme source these methods would lead to improvements in the production of l-phenylalanine. The possibilities of enriching PAL activity in recombinant E. coli was investigated by us ...
... Information about soil VOC inventories and exchange rates in different soils is very scarce. Seasonality of soil VOC exchange rates is also largely unknown, despite the increasing interest in some soil volatile compounds, such as monoterpenes, because of their important role in soil ecology. We aimed to explore and quantify soil VOC exchange rates in a Mediterranean shrubland and their seasonality ...
acetone; adsorbents; bamboos; charcoal; chromatography; detection limit; dimethyl phthalate; ionic strength; rain; solid phase extraction; tap water
Abstract:
... This paper demonstrates, for the first time, that adsorptive potential of bamboo charcoal for solid-phase extraction of phthalate esters was investigated. The four phthalate esters, dimethyl phthalate (DMP), diethyl phthalate (DEP), butyl benzyl phthalate (BBP) and di-n-butyl phthalate (DBP), are quantitatively adsorbed on a bamboo charcoal packed cartridge, then the analytes retained on the cartr ...
... An ion-chromatographic method has been developed to determine seven common anions in electronic-grade acetone, isopropyl alcohol, methanol, and N-methyl-2-pyrrolidone (NMP), solvents whose cleanliness is vital to the manufacturing of semiconductor devices. The system requires only a pump, conductivity detector, and switching valve as hardware. A calibration study was conducted first, by preparing ...
acetone; beta-cryptoxanthin; ferrous sulfate; food research; high performance liquid chromatography; iron; isomerization; lighting; lutein; mass spectrometry; normal values; oxidants; temperature; zeaxanthin
Abstract:
... Lutein, zeaxanthin, and β-cryptoxanthin are xanthophyll pigments that own conjugated double bonds; some factors can convert (all-E)-xanthophylls to their (Z)-isomers such as high temperature, illumination, and oxidants. In the present work, the Fe(II)-induced isomerization of (all-E)-lutein, (all-E)-zeaxanthin, and (all-E)-β-cryptoxanthin in acetone were analyzed by HPLC coupled with DAD and APcI- ...
... Larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone and methanol extracts of five medicinal plants, Abutilon indicum, Aegle marmelos, Euphorbia thymifolia, Jatropha gossypifolia and Solanum torvum were assayed for their toxicity against the early fourth-instar larvae of Culex quinquefasciatus. The larval mortality was observed after 24 h exposure. All extracts showed moder ...
Canarium album; acetone; electrospray ionization mass spectrometry; food research; fruit trees; gallic acid; high performance liquid chromatography; medicinal properties; nuclear magnetic resonance spectroscopy; polyamides; China
Abstract:
... Chinese olive (Canarium album L.), one native and well-known tropical fruit tree in the southeast of China, contain a large amount of phenolics and possess great pharmacological activities. In this study, phenolics were extracted from Chinese olive fruit using 80% (v/v) aqueous acetone, and seven phenolic compounds were isolated and purified by Polyamide column and Toyopearl HW-40 column chromatog ...
... The acetone, chloroform, ethyl acetate, hexane and methanol leaf extracts of Acalypha indica, Achyranthes aspera, Leucas aspera, Morinda tinctoria and Ocimum sanctum were studied against the early fourth-instar larvae of Aedes aegypti L and Culex quinquefasciatus Say. The larval mortality was observed after 24 h exposure. All extracts showed moderate larvicidal effects; however, the highest larval ...
... Aqueous extract of mate, made from dried leaves of Ilex paraguariensis, St. Hilaire, was shown to be effective during chilled storage for up to 10 days in protecting lipids and vitamin E against oxidation in pre-cooked meat balls made from chicken breast added 0.5% salt and packed in atmospheric air. Extracts made with water, methanol, ethanol or 70% aqueous acetone were evaluated by comparing (1) ...
... The selective production of acetone and butanol is highly desirable from the viewpoint of biofuel production. We have manipulated the activity level of a hydrogenase for this purpose because hydrogen and solvent production are closely correlated with each other. First, we cloned the hydrogenase gene cluster from Clostridium saccharoperbutylacetonicum strain N1-4 and downregulated its expression us ...
... A relatively simple method for the determination of azoxystrobin residues in grapes and soil using gas chromatography equipped with electron capture detector (GC-ECD) is described. Samples were extracted with acetone, and further partitioned with dichloromethane and petroleum ether. The extracts were then cleaned up in a glass clean-up column filled with active charcoal and silica gel, and eluted ...
... Two statistical mixture designs were used to optimize the proportions of solvents used in both the extraction medium and the reversed liquid chromatographic mobile phase to improve the quality of chromatographic fingerprints of Bauhinia variegata L extracts. For modeling, the number of peaks was used as a measure of fingerprint information. Three mobile phases, each with a chromatographic strength ...
... This study aims: (1) to quantify mollusc grazing on juvenile and mature thalli of the foliose epiphytic lichen Lobaria pulmonaria, and (2) to test the hypothesis inferring a herbivore defensive role of lichen depsidones in forests with indigenous populations of lichen-feeding molluscs. Lichens were transplanted in shaded and less shaded positions in each of two calcareous broadleaved deciduous for ...