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1.
《分离科学与技术》2012,47(1):227-242
Abstract

Selective recovery of aporphine alkaloids from Glaucium flavum Crantz was studied. The alkaloids were successfully recovered from aqueous solutions, including native extracts of Glaucium flavum Crantz, applying pertraction in a rotating discs contactor. As a liquid membrane n-heptane and as receiving solution diluted phosphoric acid were used. Pertraction was also coupled to solid-liquid extraction in order to simultaneously purify the extract obtained from the plant. This integrated extraction-pertraction process was very simple, rapid, and efficient. The permeation of alkaloids through the liquid membrane was very selective and their purity in the receiving solution was 88.7%.  相似文献   

2.
Melissa officinalis is a medicinal plant rich in biologically active compounds which is used worldwide for its therapeutic effects. Chemical studies on its composition have shown that it contains mainly flavonoids, terpenoids, phenolic acids, tannins, and essential oil. The main active constituents of Melissa officinalis are volatile compounds (geranial, neral, citronellal and geraniol), triterpenes (ursolic acid and oleanolic acid), phenolic acids (rosmarinic acid, caffeic acid and chlorogenic acid), and flavonoids (quercetin, rhamnocitrin, and luteolin). According to the biological studies, the essential oil and extracts of Melissa officinalis have active compounds that determine many pharmacological effects with potential medical uses. A new field of research has led to the development of controlled release systems with active substances from plants. Therefore, the essential oil or extract of Melissa officinalis has become a major target to be incorporated into various controlled release systems which allow a sustained delivery.  相似文献   

3.
《分离科学与技术》2012,47(4):588-593
Rosmarinic acid and rutin were successfully separated from Glechoma hederaceaL. using high-speed counter-current chromatography for the first time. Eleven milligrams of rosmarinic acid (chromatographic purity 97.2 %) and 10 mg of rutin (chromatographic purity 98.1 %) were obtained from 100 mg ethyl acetate extract and 100 mg n -butanol extract of Glechoma hederacea L., respectively, with the separation procedure less than 2 h. Their structures were characterized by UV, MS, and NMR. The established methods were simple, fast, and convenient, which can be applied to the preparation of reference substances of rosmarinic acid and rutin.  相似文献   

4.
《分离科学与技术》2012,47(7):591-600
Abstract

The extraction/preconcentration of mercury(II) from aqueous media using diphenyl-2-pyridylmethane (DPPM) in benzene has been studied. The factors influencing the extraction are optimized. An extractive preconcentration procedure has been proposed on the basis of its quantitative extraction in a single equilibration from 1 M hydrochloric acid solution containing 0.02 M potassium thiocyanate. Extracted mercury can be stripped almost completely into 10 M aqueous solutions of hydrochloric or perchloric acid. A mechanism has been proposed, and the extractable species is assumed to be HgCl2—n (SCN) n (DPPM)2, where n = 1,2. Aqueous to organic volume ratios up to 100:1 can be used without loss of extraction efficiency, and the procedure can effectively be used in water pollution abatement studies.  相似文献   

5.
《分离科学与技术》2012,47(2):315-327
Abstract

N,N′‐bis(salicylidene)‐1,2‐phenyldiamine was synthesized for examining their ability to extract and transport Cu2+ through a liquid membrane. By using hydrazine sulfate and potassium thiocyanate as reducing agent and acceptor respectively in the receiving phase at the optimum pH of 1.5, the amount of copper transported across the liquid membrane after 3.5 hours was 96%. The selectivity and efficiency of copper transport from aqueous solution containing various metal ions were investigated.  相似文献   

6.
Stratum corneum (SC) pH regulates skin barrier functions and elevated SC pH is an important factor in various inflammatory skin diseases. Acidic topical formulas have emerged as treatments for impaired skin barriers. Sodium proton exchanger 1 (NHE1) is an important factor in SC acidification. We investigated whether topical applications containing an NHE1 activator could improve skin barrier functions. We screened plant extracts to identify NHE1 activators in vitro and found Melissa officinalis leaf extract. Rosmarinic acid, a component of Melissa officinalis leaf extract, significantly increased NHE1 mRNA expression levels and NHE1 production. Immunofluorescence staining of NHE1 in 3D-cultured skin revealed greater upregulation of NHE1 expression by NHE1 activator cream, compared to vehicle cream. Epidermal lipid analysis revealed that the ceramide level was significantly higher upon application of the NHE1 activator cream on 3D-cultured skin, compared to application of a vehicle cream. In a clinical study of 50–60-year-old adult females (n = 21), application of the NHE1 activator-containing cream significantly improved skin barrier functions by reducing skin surface pH and transepidermal water loss and increasing skin hydration, compared to patients who applied vehicle cream and those receiving no treatment. Thus, creams containing NHE1 activators, such as rosmarinic acid, could help maintain or recover skin barrier functions.  相似文献   

7.
《分离科学与技术》2012,47(2):141-152
Abstract

An experimental study is presented on the separation of cobalt(II) cations from an aqueous solution by means of liquid surfactant membranes containing the ion exchanger di(2-ethylhexyl)phosphoric acid. The process was studied at various emulsifier (Span 80) concentrations, membrane viscosities, pHs, and rates of stirring as well as at various KNO3 and cobalt concentrations. Cobalt recovery over 99% was achieved with up to tenfold enrichment. A substantial difference of the process course for cobalt and copper was found which allowed for their effective separation.  相似文献   

8.
《分离科学与技术》2012,47(12-13):981-999
Abstract

A new type of liquid membrane named a “flowing liquid membrane” is proposed. In this type of liquid membrane, a liquid membrane solution containing a carrier flows in thin channels between two hydrophobic micro-porous membranes which separate the membrane solution from a feed and a strip solution, and forms a stable liquid membrane. The flowing liquid membrane was made into a spiral-type module, and experiments on the separation and enrichment of Cr(VI) in aqueous solutions were performed with the flowing membrane module using tri-n-octylamine as the carrier. It was found that this type of module has high stability as well as high performance, and Cr(VI) was successfully removed and concentrated from its dilute solutions. The result on the recovery of zinc using di(2-ethylhexyl)phosphoric acid as the carrier is also presented.  相似文献   

9.
Persimmon fallen leaves were employed to prepare a renewable and low‐cost biosorbent named as NPFL. Effects of initial pH, contact time, initial Pb(II) concentration, coexisting metal ions, and ionic strength on adsorption of Pb(II) from aqueous solution by NPFL were studied in detail. Enhanced removal capacity of NPFL toward Pb(II) was observed, and the maximum adsorption capacity was evaluated as 256 mg g?1 by Langmuir modeling calculation. The fast adsorption process and the well‐fitted kinetics data with pseudo‐second‐order model indicated that chemisorption is the main rate‐limiting step for the adsorption process. NPFL had superior adsorption selectivity for Pb(II) from aqueous solution with coexisting metal ions. Characterization of NPFL and adsorption mechanism (electrostatic attraction, ion exchange, and chelation) were performed using XRD, SEM‐EDS, FT‐IR, XPS, and TGA. The results suggested that NPFL could be utilized as a potential candidate for the preconcentration of Pb(II) recovery and its removal in practice. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43656.  相似文献   

10.
Various electrochemical techniques were employed to study the effectiveness of aqueous Ficus carica (Fig. tree) leaves extract as green corrosion inhibitor for mild steel under field conditions containing 3.5% sodium chloride solution saturated with carbon dioxide. Optimum inhibition efficiency of 90% was obtained using 50 mg/L of inhibitor in the temperature range of 25–40 °C. The mode of action of Ficus carica leave extract as revealed by Polarization studies was shown to act as a mixed inhibitor. The adsorption isotherm of the adsorption of Ficus carica leaves extract on the steel surface was found to follow Langmuir adsorption isotherm. In order to assess the individual contribution of the different constituents of the extract theoretically, the adsorption of the four major organic constituents of Ficus carica leave extract on mild steel were modelled using density functional theory and quench molecular dynamic simulations. Among the four major Ficus carica leaves extract constituent investigated, Caffeoylmalic acid was found to make the most contribution to the overall inhibition action of Ficus carica leaves extract.  相似文献   

11.
ABSTRACT

A rapid and robust preparation method of six isoflavones from ethanol aqueous extract of Iris tectorum Maxim (I. tectorum) was established by using macroporous resin column chromatography and preparative high-performance liquid chromatography (Prep-HPLC). After separation by AB-8 resins, total flavonoids content increased from 10.60% in the crude extract to 54.20% with a recovery yield of 75.12%. Subsequently, the extracts were purified by Prep-HPLC, and the purities were more than 82.2% after assessment by analytical HPLC and characterization by mass spectrometry. The established method is expected to be used for preparing available quantities of pure isoflavones from I. tectorum.  相似文献   

12.
Rosmarinic acid has been separated by facilitated pertraction with D2EHPA dissolved in dichloromethane. The pertraction has been carried out in presence of 1-octanol, added into the liquid membrane. The addition of the alcohol led to the increase for more than twice the rosmarinic acid initial and final mass flows, this effect being directly related to the process variables (pH-gradient between the aqueous phases, carrier and alcohol concentrations inside the membrane phase, mixing intensity). But, the influence of 1-octanol on the transport capacity of the pertraction system was negative, its addition inducing the accumulation of rosmarinic into the liquid membrane. Due to this effect, the reevaluation and optimization of the reextraction process from the membrane phase to the stripping are required.  相似文献   

13.
Flavonoid constituents from the aqueous extract of the leaves of Eupatorium odoratum, an invasive weed in Thailand, have potential use as dyestuffs for cotton dyeing. It was found that cotton yarn, which was pretreated with a chitosan solution (with and without a crosslinking glyoxal solution), followed by dyeing with E. odoratum extract in the presence of the inorganic mordant, alum, provided better depth of shade (K/S) and also gave better fastness to light and washing than the untreated cotton yarn. Pretreated cotton yarn with the biomordant solution from Memecylon scutellatum leaves gave relatively poor light and wash fastness of the resultant dyed cotton in the presence of alum. From the toxicity studies, the aqueous extract of the leaves of E. odoratum before and after dyeing showed a high toxicity level to the earthworm (Diplocardia communis) and the guppy fish (Poecilia reticulate). Therefore, it is strongly suggested that E. odoratum aqueous extract after dyeing should be significantly diluted before discharged into the environment.  相似文献   

14.
ABSTRACT

The stripping rate of propionic acid from microcapsules containing tri-n-octyl amine was investigated using distilled water and aqueous NaOH as stripping solutions. The experiments were conducted at 303K. The stripping rate was found to be controlled by diffusion through porous microcapsule membrane and increased with an increase in the concentration of propionic acid in the microcapsules for each solution system. It was found that the stripping rates in aqueous NaOH solution system was higher than in distilled water at the same concentration of propionic acid in microcapsules. The experimental results in the NaOH solution system could be analyzed using a permeation model considering mass transfer accompanied by irreversible instantaneous neutralization reaction between NaOH and the propionic acid/tri-n-octyl amine complex in the microcapsule membrane.  相似文献   

15.
《分离科学与技术》2012,47(5):1181-1197
Abstract

In this paper, hollow fiber renewal liquid membrane (HFRLM) and hollow fiber supported liquid membrane (HFSLM) were used to simultaneously remove and recover copper(II) from aqueous solutions, and the transport performance of these two techniques were compared under the similar conditions for the system of CuSO4 +D2EHPA in kerosene +HCl. The results showed that the HFRLM process was more stable than the HFSLM process. The HFRLM process had a higher overall mass transfer coefficient than that of HFSLM process in single-pass experiments. These were because the renewal effect of the liquid membrane layer could reduce the mass transfer resistance of the lumen side and replenish the loss of the membrane liquid in the HFRLM process. The transport results were better in the HFRLM process than that in the HFSLM process with recycling experiments. Therefore, HFRLM technique is a promising method for simultaneous removal and recovery of heavy metal from aqueous solutions.  相似文献   

16.
《分离科学与技术》2012,47(8):1043-1054
Abstract

Nickel(II) and bismuth(III) are quantitatively extracted from aqueous thiocyanate solutions, adjusted to pH 4.0–9.0 and 3.5–5.0, respectively, using solutions of 1-(2-pyridylazo)-2-naphthol (PAN) in tri-n-butyl phosphate (TBP). The extracted species of nickel and bismuth have the formulas [Ni(PAN)SCN]·4TBP and [Bi(PAN)SCN]X·TBP, respectively. Polyurethane foam treated with TBP solution containing PAN is used successfully for the quantitative retention and recovery of nickel and bismuth from aqueous thiocyanate solutions in the column extraction mode. The preconcentration of small amounts (10 mg) of nickel and bismuth from dilute aqueous solutions (1 L) is also possible, with a recovery of 95–97%. The feasibility of using PAN-foam for selective detection and semiquantitative determination of nickel and bismuth in aqueous thiocyanate media is examined. The detection limits of nickel and bismuth by the foam batch method are 0.05 and 0.50 ppm, respectively. Lower concentrations of these metal ions are easily detected in dynamic tests using PAN-foam columns. Semiquantitative determination of nickel and bismuth is also achieved in both the batch and column methods by using the appropriate color scales.  相似文献   

17.
The extraction and recovery or stripping of mercury ions from chloride media using microporous hydrophobic hollow fiber supported liquid membranes (HFSLM) has been studied. Tri-n-octylamine (TOA) dissolved in kerosene was used as an extractant. Sodium hydroxide was used as a stripping solution. The transport system was studied as a function of several variables: the concentration of hydrochloric acid in the feed solution, the concentration of TOA in the liquid membrane, the concentration of sodium hydroxide in the stripping solution, the concentration of mercury ions in the feed solution and the flow rates of both feed and stripping solutions. The results indicated that the maximum percentages of the extraction and recovery of mercury ions of 100% and 97% were achieved at the concentration of hydrochloric acid in the feed solution of 0.1 mol/l, the concentration of TOA at 3% v/v, the concentration of sodium hydroxide at 0.5 mol/l and the flow rates of the feed and stripping solutions of 100 ml/min. However, the concentration of mercury ions from 1–100 ppm in the feed solution had no effect on the percentages of extraction and recovery of mercury ions. Thus, these results have identified that the hollow fiber supported liquid membrane process has high efficiency on both the extraction and recovery of mercury (II) ions. Moreover, the mass transfer coefficients of the aqueous phase (k i ) and membrane or organic phase (k m ) were calculated. The mass transfer coefficients of the aqueous phase and organic phase are 0.42 and 1.67 cm/s, respectively. The mass transfer coefficient of the organic phase is higher than that of the aqueous phase. Therefore, the mass transfer controlling step is the diffusion of the mercury ions through the film layer between the feed solution and the liquid membrane.  相似文献   

18.
The corrosion inhibition of aluminum in sulphuric acid using an aqueous extract of leaves of Morinda tinctoria (MT) was studied with weight loss and electrochemical techniques. It was found that the MT extract acts as a good inhibitor for aluminum corrosion in the sulphuric acid medium. The inhibition efficiency of the inhibitor is found to increase with the increase in concentration of the acid. Synergistic effect increased the inhibition efficiency of MT in the presence of halide additives. The process of adsorption of the inhibitor on the metal surface is found to obey Freundlich isotherm. The adsorbed film on the metal surface has been analyzed by FT-IR and SEM-EDXS studies. Polarization measurements showed that MT extract is a mixed type inhibitor. Impedance results indicate adsorption of the MT on the Al surface is through charge transfer.  相似文献   

19.
Metopium brownei is a tree that grows in coastal tropical forests along the Gulf of Mexico and in the Yucatan Peninsula. This medicinal species produces a strongly irritant exudate, and sometimes forms pure populations favored by fire. The bioactivity of the aqueous leachates, organic extracts (leaves, bark, and wood), and mixtures of urushiols and flavonoids from M. brownei were evaluated on the growth of two plants: Amaranthus hypochondriacus and Echinochloa crusgalli, and four phytopathogenic fungi: Fusarium oxysporum, Helminthosporium sp., Alternaria sp., and Pythium sp. Alkylcatechols (urushiols) were isolated from an acetone extract of the bark. Dihydroquercetin and eriodictyol were isolated from the chloroform–methanol extract of the wood. In addition, masticadienoic acid was isolated from the leaves. The aqueous leachates, organic extracts, and the mixtures of flavonoids and urushiols were inhibitory to the growth of test plants and phytopathogenic fungi. The allelochemical role of the bioactive compounds from M. brownei is discussed in relation with other results reported in some studies on Anacardiaceae family and M. brownei.  相似文献   

20.
《分离科学与技术》2012,47(13-15):2097-2108
Abstract

Acetic acid is presently recovered from terephthalic acid flowsheets by distillation. This paper documents a preliminary evaluation of extraction for its recovery and recycle. Experimental data show that the solvent has a selectivity for acetic acid-water of 5 for a 50 wt. percent acid solution and 60 for 5 wt. percent acid solution. Above 10 wt. percent extractant in the solvent, addition of extractant to the solvent has the combined effect of decreasing the solvent loss to the aqueous phase and decreasing the loading of water in the solvent. The high selectivities of the solvent for acid vs. water combined with the high relative volatility of the acid vs. the solvent imply that lower energy costs with an extraction flowsheet over distillation is likely.  相似文献   

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