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A novel on-line three-dimensional liquid chromatography method was developed to separate four main flavonoids from Rhodiola rosea. Ethyl acetate/0.5 mol/L ionic liquid 1-butyl-3-methylimidazolium chloride aqueous solution was selected as the solvent system. In the first-dimension separation, the target flavonoids were entrapped and subsequently desorbed into the second-dimension high-speed countercurrent chromatographic column for separation. In the third-dimension chromatography, the residual ionic liquid in the four separated flavonoids was removed and the used ionic liquid was recovered. As a result, 35.1 mg of compound 1, 20.4 mg of compound 2, 8.5 mg of compound 3, and 10.6 mg of compound 4 were obtained from 1.53 g R. rosea extract. They were identified as rhodiosin, rhodionin, herbacetin, and kaempferol, respectively. The recovery of ionic liquid reached 99.1% of the initial amount. The results showed that this method is a powerful technology for the separation of R. rosea flavonoids and that the ionic-liquid-based solvent system has advantages over traditional solvent systems in renewable and environmentally friendly properties., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Highlights: [•] A new method was developed to separate four flavonoids from Rhodiola rosea. [•] The merits of the method were low solvent consumption and no tedious sample pre-treatment. [•] The two of the four flavonoids were separated first time from Rhodiola rosea. [ABSTRACT FROM AUTHOR]

Rosavin was a major active compound from Rhodiola rosea. It is known that it possesses stimulant, antidepressant, and anticancer properties. In the present study, a two-step flash column chromatography has been developed for the large-scale preparative separation and purification of rosavin from the extracts of Rhodiola rosea, which were obtained by microwave assisted extraction (MAE) using ion liquids (ILs) as extraction solvent under the optimized conditions (microwave power 1200 W, extraction time 6 min, solid-liquid ratio 1:20, microwave temperature 120°C) resulting from the analysis of the D-optimal design. In the first separation, the Rhodiola rosea extract was loaded into polyamide and HPD-200 macroporous resin flash columns in series for efficient enrichment of rosavin. In the second one, the rosavin-rich crude sample after the serial column chromatography was subjected to final purification by silica gel flash chromatography. After the two-step separation, 529.1 mg of rosavin was obtained at a purity of 98.2% and a recovery of 60.6%. The separation process can provide a new method for large-scale separation and purification of rosavin for its pharmaceutical and practical use. [ABSTRACT FROM PUBLISHER]

Bamboo powder and its dissolution process in ionic liquids were analyzed according to Fourier Transform Infrared Spectroscopy (FT-IR) coupled with two-dimensional correlation spectroscopy and chemometrics. Second derivative spectroscopy was applied to enhance the spectra resolution, obtaining more molecular vibration information. After executing the principal component analysis (PCA) on ATR-FTIR spectra of undissolved bamboo powder residue, we obtained a three-staged dissolution process model. In addition, the conclusion that cellulose/hemicellulose dissolving prior to lignin was summarized through the PCA loading spectrum. Point-line moving window two dimensional correlation spectroscopy (PL-MW2DCOS) furtherly unveiled the dissolution details. This work provided us a clear dissolution process of biomass using a rapid, label-free and easy-operation method. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel ionic liquid based biphasic solvent is proposed for CO 2 capture. • Co-solvent with ultra-low vapor pressure increases absorption capacity. • CO 2 -rich phase concentrates 95.2% of the capacity, with 40% of the total volume. • CO 2 -rich phase of this solvent could regenerate without lean phase. • The regeneration efficiency of this solvent remains 83% after ten cycles at 373 K. A novel, sustainable, dual-functionalized amino ionic liquid biphasic solvent of 3-(Dimethylamino)-1-propylamine-1,2,4-triazole/poly (ethylene glycol) dimethyl ether/water ([DMAPA][TZ]/NHD/water) was proposed for CO 2 capture to reduce the consumption of regeneration energy. Experimental results showed that the CO 2 absorption loading of the solvent was 1.95 mol CO 2 ·L−1 solvent at a CO 2 partial pressure of 15 kPa. The volume of the CO 2 -rich phase was 40 vol% of the total volume, with a loading of up to 4.65 mol CO 2 ·L−1 solvent, accounting for approximately 95.4% of the blended CO 2 loading in the solvent. The CO 2 -rich phase could be regenerated by 92.3% in 10 min at 373 K, without the presence of a lean phase. The regeneration efficiency of the solvent was maintained at 83% after 10 adsorption and desorption cycles. The reaction, regeneration, and phase-change mechanism were investigated using 13C NMR and phase composition analysis. CO 2 reacted with [DMAPA][TZ] to form two kinds of carbamate during solubilization, and all carbamates could be further hydrolyzed to form HCO 3 − and CO 3 2−. The solvent effect, phase-change behavior, and CO 2 physical dissolution of NHD could promote the absorption and desorption rate and absorption capacity of CO 2. The energy consumption for CO 2 desorption could be reduced to 1.335 GJ·t−1 CO 2 , which was 67% lower than that of 30 wt% ethanolamine (3.99 GJ·t−1 CO 2), given the lower heat of reaction, specific heat capacity, and solvent loss. Thus, this solvent presents a sustainable strategy for advancing carbon capture technologies. [ABSTRACT FROM AUTHOR]