Search

(1) Background: Ionic liquids (ILs) are considered "green" solvents and have been widely used in the extraction and separation field in recent years; (2) Methods: In this study, some common ILs and functionalized magnetic ionic liquids (MILs) were used as adjuvants for the solvent extraction of paclitaxel from Taxus x media ( T. x media ) using methanol solution. The extraction conditions of methanol concentration, IL type and amount, solid-liquid ratio, extraction temperature, and ultrasonic irradiation time were investigated in single factor experiments. Then, three factors of IL amount, solid-liquid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM); (3) Results: The MIL [C₄MIM]FeCl₃Br was screened as the optimal adjuvant. Under the optimization conditions of 1.2% IL amount, 1:10.5 solid-liquid ratio, and 30 min ultrasonic irradiation time, the extraction yield reached 0.224 mg/g; and (4) Conclusions: Compared with the conventional solvent extraction, this ultrasonic assisted extraction (UAE) using methanol and MIL as adjuvants can significantly improve the extraction yield, reduce the use of methanol, and shorten the extraction time, which has the potentiality of being used in the extraction of some other important bioactive compounds from natural plant resources., Competing Interests: The authors declare no conflict of interest.

The ultrasonic assisted temperature-switch ionic liquid microextraction (UATS-ILME) has been successfully applied in extracting of seven lignans from Schisandra. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) aqueous solution was selected for extracting the target analytes in raw material at 80°C. The lignans were deposited into a single drop by in situ forming 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) by cooling down to 0°C and centrifuging for 10min. The extracts were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in a robust multiple-reaction monitoring (MRM) mode in five minutes. Meanwhile, the proposed method was validated and successfully applied to the determination of seven lignans in twelve Schisandra species. The results indicated that UATS-ILME combined with UPLC-MS/MS is a powerful and practical tool, which has great potential for comprehensive quality control of herbal medicines., (Copyright © 2015 Elsevier B.V. All rights reserved.)

(1) Background: Ionic liquids (ILs) are considered "green" solvents and have been widely used in the extraction and separation field in recent years; (2) Methods: In this study, some common ILs and functionalized magnetic ionic liquids (MILs) were used as adjuvants for the solvent extraction of paclitaxel from Taxus x media (T. x media) using methanol solution. The extraction conditions of methanol concentration, IL type and amount, solid--liquid ratio, extraction temperature, and ultrasonic irradiation time were investigated in single factor experiments. Then, three factors of IL amount, solid--liquid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM); (3) Results: The MIL [C4MIM]FeCl3Br was screened as the optimal adjuvant. Under the optimization conditions of 1.2% IL amount, 1:10.5 solid--liquid ratio, and 30 min ultrasonic irradiation time, the extraction yield reached 0.224 mg/g; and (4) Conclusions: Compared with the conventional solvent extraction, this ultrasonic assisted extraction (UAE) using methanol and MIL as adjuvants can significantly improve the extraction yield, reduce the use of methanol, and shorten the extraction time, which has the potentiality of being used in the extraction of some other important bioactive compounds from natural plant resources [ABSTRACT FROM AUTHOR]

In this paper, response surface methodology was employed to optimize experimental process for ionic liquid based ultrasonic assisted extraction of curcuminoids compounds from rhizomes of Curcuma longa L. The Box–Behnken design on three factors and five levels together with response surface methodology were used to optimize experimental conditions for total curcuminoids content and radical scavenging capacity. The radical scavenging capacity was determined by ABTS and TRAP methods. For the ionic liquid based ultrasonic assisted extraction, optimum process was set as below: [Omim]Br concentration, 4.2 mol/L; liquid-raw ratio, 30 mL/g; extraction time, 90 min; ultrasonic power, 250 W. [ABSTRACT FROM AUTHOR]

A simple, highly sensitive and environment-friendly method, combined with flame atomic absorption spectroscopy (FAAS) is developed to preconcentrate and determine trace amounts of thallium in aqueous solutions. In the preconcentration step, the thallium (I) from 30 mL of an aqueous solution was extracted into 350 µL of ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF6], containing dicyclohexyl-18-crown-6 (DCH-18-crown-6) as complexing agent. Subsequently, the DCH-18-crown-6 complex was back-extracted into 300 µL of nitric acid (2 mol L−1) solution, and analyzed by FAAS. Several parameters influencing the extraction and determination of thallium, such as pH, concentration of DCH-18-crown-6, sonication and centrifugation times, sample volume, ionic liquid amounts, ionic strength, and concentration of stripping acid solution, were optimized. Under optimum conditions, the calibration graph was linear in the range of 5 to 400 ng mL−1, the detection limit was 0.64 ng mL−1(3Sb/m,n = 7), the enhancement factor was 98.2 and the relative standard deviation was ±1.43%. The results for preconcentration and determination of trace amount of thallium in waste water, well water, tap water, sea water, human hair and nail demonstrated the accuracy, recovery and applicability of the presented method. [ABSTRACT FROM PUBLISHER]

Abstract: We developed an aqueous ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the eight ginsenosides (ginsenoside-Rg1, -Re, -Rf, -Rb1, -Rc, -Rb2, -Rb3 and -Rd) from ginseng root. A series of l-alkyl-3-methylimidazolium ionic liquids differing in composition of anions and cations were evaluated for extraction efficiency. The results indicated that the ILUAE method has a remarkable ability to improve the extraction efficiency of ginsenosides. In addition, the ILUAE procedure was also optimized on some ultrasonic parameters, such as the IL concentration, solvent to solid ratio and extraction time. Under these optimal conditions (e.g., with 0.3M [C3MIM]Br, solvent to solid ratio of 10:1 and extraction time of 20min), this approach gained the highest extraction yields of total ginsenosides 17.81±0.47mg/g. Compared with the regular UAE, the proposed approach exhibited 3.16 times higher efficiency and 33% shorter extraction time, which indicated that ILUAE has a broad prospect for sample preparation of medicinal plants. [Copyright &y& Elsevier]

Abstract: In this study, an aqueous ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the four acetophenones, namely 4-hydroxyacetophenone (1), 2,5-dihydroxyacetophenone (2), baishouwubenzophenone (3) and 2,4-dihydroxyacetophenone (4) from the Chinese medicinal plant Cynanchum bungei was developed. Three kinds of aqueous l-alkyl-3-methylimidazolium ionic liquids with different anion and alkyl chain were investigated. The results indicated that ionic liquids (ILs) showed remarkable effects on the extraction efficiency of acetophenones. In addition, the ILUAE, including several ultrasonic parameters, such as the ILs concentration, solvent to solid ratio, power, particle size, temperature, and extraction time have been optimized. Under these optimal conditions (e.g., with 0.6M [C4MIM]BF4, solvent to solid ratio of 35:1, power of 175W, particle size of 60–80 mesh, temperature of 25°C and time of 50min), this approach gained the highest extraction yields of four acetophenones 286.15, 21.65, 632.58 and 205.38μg/g, respectively. The proposed approach has been evaluated by comparison with the conventional heat-reflux extraction (HRE) and regular UAE. The results indicated that ILUAE is an alternative method for extracting acetophenones from C. bungei. [Copyright &y& Elsevier]

Abstract: Ionic liquid (IL) based ultrasonic assisted extraction (ILUAE) was developed for the effective extraction of puerarin from Radix Puerariae Lobatae (RPL). The ILUAE parameters including the type of ILs, IL concentration, RPL amount, ultrasonic power and time were optimized by single-factor experiment and response surface methodology. Under the optimized experimental conditions, the best results were obtained using RPL amount 0.43g in 10mL 1.06molL−1 1-butyl-3-methylimidazolium bromide aqueous solution, ultrasonic time 27.43min and ultrasonic power 480W. Scanning electron microscope images of RPL samples were obtained to provide visual evidence of the sonication effect. Compared with the conventional ultrasonic assisted extraction and refluent extraction, the proposed ILUAE offered shorter extraction time and remarkable higher efficiencies due to the higher penetration ability and solubility of IL and the cavitation phenomenon produced in the solvent by the passage of an ultrasonic wave, which further supported the suitability of the proposed approach. [Copyright &y& Elsevier]

Abstract: We developed an ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the three isoflavones, namely tectoridin, iristectorin B and iristectorin A from Iris tectorum Maxim of the Iridaceae family. Three kinds of 1-alkyl-3-methylimidazolium ionic liquids with different alkyl chain and anion were investigated. The results indicated that ionic liquids (ILs) showed remarkable effects on the extraction yield of isoflavones. In addition, the ILUAE, including several ultrasonic parameters, such as the concentration, extraction time and solvent to solid ratio have been optimized. Under these optimal conditions (e.g., with 30min extraction time and the solvent to solid ratio of 30ml/g), this approach gained the highest extraction yields of tectoridin (37.45mg/g), iristectorin B (2.88mg/g) and iristectorin A (5.28mg/g). Meanwhile, tectoridin, iristectorin B and iristectorin A in the ILUAE extract were separated and purified successfully through the high-speed counter-current chromatography (HSCCC) with a two-phase solvent system consisting of n-butanol–water (1:1, v/v). The additional advantage of this approach is that 60.21mg tectoridin, 4.33mg iristectorin B and 8.24mg iristectorin A with more than 95.0% purities have been obtained from 400mg ILUAE extract of I. tectorum within 5h and one-step elution under the most optimized conditions (e.g., a flow rate of 2.0ml/min, 900rpm and the wavelengh of 280nm). The obtained fractions were successfully analyzed by HPLC and identified by 1H-NMR and 13C-NMR. [Copyright &y& Elsevier]

Abstract: In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid–liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300μL ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0–500.0ngmL−1, the detection limit was 0.37ngmL−1 (3S b/m, n =7) and the relative standard deviation was ±1.63% (n =7, C =200ngmL−1). The results show that ionic liquid based ultrasound assisted dispersive liquid–liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption. [ABSTRACT FROM AUTHOR]

To effectively extract the pigment from chestnut shell in a green and efficient way, an eco-friendly and efficient method based on ionic liquid ultrasonic assisted extraction (IL-UAE) was established. The effect of a series of 1-alkyl-3-methyl imidazole ionic liquids on the yield was investigated. The results indicated that the chain length of ionic liquids and the properties of anions and cations had a significant impact on the extraction, and 1-butyl-3-methylimidazolium acetate ([Bmim]OAc) had the best extraction effect. In addition, the concentration of bond breaking agent (sodium dodecyl sulfate, urea), concentration of [Bmim]OAc, liquid-solid ratio, extraction power, time, temperature and other parameters were tested by single factor. Sodium dodecyl sulfate (SDS), urea concentration and liquid-solid ratio were optimized by response surface methodology (RSM). The optimal process conditions were as follows: SDS concentration of 0.44% (w/v), urea concentration of 2.87% (w/v), [Bmim]OAc concentration of 1.07 mol/L, liquid-solid ratio of 36.26 mL/g, ultrasonic power of 350 W, ultrasonic time of 50 min, and ultrasonic temperature of 80 °C, respectively. Under these conditions, the yield was 71.60 mg/g. Compared with the conventional reflux extraction with organic solvents (sodium hydroxide, ethanol), the optimized method improved the yield by 42.24% and 38.70% in a shorter time (50min versus 120min), respectively. The physico-chemical properties of hair dyed with chestnut shell pigment extracted by IL-UAE were compared with those extracted by conventional organic solvents. The results showed that the former showed excellent color intensity, smooth hair surface morphology and low internal damage than the latter. Our results helped to accelerate the high-value applications of chestnut wastes. [Display omitted] • Bond breaking agents' combination helps to improve the extraction efficiency. • IL-UAE is an eco-friendly and high efficient method for extracting pigment from chestnut shells. • Hair dyeing capability of chestnut shell pigment extracted by IL-UAE was superior to that obtained by conventional methods. [ABSTRACT FROM AUTHOR]