نتایج جستجو برای: extraction of pahs by sfe
تعداد نتایج: 21627770 فیلتر نتایج به سال:
abstract polycyclic aromatic hydrocarbons (pahs) are classified as persistent and carcinogenic organic pollutants. pahs contamination has been reported in water. many of relevant regulatory bodies such as eu and epa have regulated the limit levels for pahs in drinking water. in this study, 13 priority polycyclic aromatic hydrocarbons (pahs) were determined in tap water samples of tehran and wat...
Background and Objective: This study conducted to assess ecological risk of an important group of pollutants called polycyclic aromatic hydrocarbons (PAHs) in offshore sediment of the Persian Gulf deposits in Bushehr province. The aim of this study was to model the toxicity of PAHs for aquatic organisms in the study area. Materials and Methods: In the first step of the applied risk assessment ...
Supercritical fluid extraction (SFE) of the volatile oil from Thymus vulgaris L. aerial flowering parts was performed under different conditions of pressure, temperature, mean particle size and CO(2) flow rate and the correspondent yield and composition were compared with those of the essential oil isolated by hydrodistillation (HD). Both the oils were analyzed by GC and GC-MS and 52 components...
A method is developed for the determination of melengestrol acetate in bovine fat tissue at or less than the established tolerance level of 25 ppb. The procedure uses a combination of supercritical fluid extraction (SFE) and solid-phase extraction (SPE) techniques to produce an extract suitable for analysis with either high-performance liquid chromatography with ultraviolet detection or gas chr...
The brewery industry generates waste that could be used to yield a natural extract containing bioactive phenolic compounds. We compared two methods of purifying the crude extract-solid-phase extraction (SPE) and supercritical fluid extraction (SFE)--with the aim of improving the quality of the final extract for potential use as safe food additive, functional food ingredient, or nutraceutical. T...
The goal of present study was to investigate kinetics of supercritical carbon dioxide (SC CO2) extraction of essential oils from dried clove buds and oregano leaves. Total extract yields after exhaustion of plant material at 10 MPa and 40°C (after consumption of 94.3 kgCO2/kg plant material) were 18.2% and 1.0 %, respectively. Synergistic effect in the extraction process was also investigated u...
the phenolic compounds of pomegranate (punica granatum l.) peel extracted by two methods (solvent and ultrasound-assisted) with five solvents (acetone, methanol, ethanol, water and ethyl acetate) were compared with supercritical fluid extraction (sfe). the total phenolic compounds were determined according to the folin-ciocalteu reagent using tannic acid as standard. the overall results showed ...
A solid-phase extraction (SPE) method for sample clean-up and preconcentration followed by reversed-phase high-performance liquid chromatography (RP-HPLC) with uv detection is reported for determination of polycyclic aromatic hydrocarbons (PAHs) in the caspian seawater. A good resolution was obtained using acetonitrile:water (40:60) as mobile-phase for separation of these compounds. The eff...
The main objective of the present study was to investigate the effect of solvent type and ratio as well as the extraction techniques (i.e. supercritical fluid extraction (SFE) and conventional solvent extraction) on betacyanins and antioxidant activity of the peel and fresh extract from the red pitaya (Hylocereus polyrhizus). The peel and flesh extracts obtained by SFE at 25MPa pressure and 10%...
In the last few decades, the search for bioactive compounds or “target molecules” from natural sources or their by-products has become the most important application of the supercritical fluid extraction (SFE) process. In this context, the present research had two main objectives: (i) to verify the effectiveness of a two-step SFE process (namely, a preliminary Sc-CO2 extraction of carotenoids f...
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