Interactions of 1-hexyl-3-methylimidazolium Bromide with Acetone

^1H and ^13C NMR chemical shifts were determined to investigate the interactions of acetone with a room temperature ionic liquid 1-hexyl-3- methylimidazolium bromide [C6mim]Br at various mole fractions. Changes in chemical shifts of hydrogen nuclei and of carbon nuclei with the acetone concentration indicated the formation of hydrogen bond between anion of the ionic liquid and methyl protons of acetone. The NMR results were in good agreement with the ab initio computational results.

Separation/Analysis Rhodamine B by Anion Surfactant/Ionic Liquid Aqueous Two-Phase Systems Coupled with Ultraviolet Spectrometry

A novel method for the separation/analysis rhodamine B has been described. The ionic liquid (1-tetradecyl-3-methylimidazolium bromide)/anion surfactant (sodium dodecyl sulfate)/NaCl two-phase systems (ATPSs) is presented as a simple, rapid and effective sample pretreatment technique coupled with ultraviolet spectrometry for analysis rhodamine B in soft drink. The effects of parameters on the ATPSs extraction of rhodamine B such as amount of surfactant, ionic liquid and salt, pH, temperature, stabilization and centrifugal time have been studied in details. Under the optimized conditions, the linear range of calibration curve for rhodamine B was 0.05 - 7.0 μg·mL-1 and the detection limit was 3.2 ng·mL-1. The phase equilibrium and the mechanism of phase separation for ATPSs have been discussed. This method has been applied to the determination of rhodamine B in soft drink.

Valorization of Asparagus leafy by-product by ionic-liquid extraction and characterization of bioactive compounds in the extracts

Asparagus(Asparagus officinalis)is a high-value low-calorie vegetable with array of bioactive compounds.Asparagus processing nevertheless generates substantial quantity of by-products;their valorization is of utmost importance for the sustainability of the industry.Here,feasibility of using four imidazolium-based ionic liquids and their combinations as well as water and methanol to extract bioactive compounds from asparagus leafy by-product was investigated.Effectiveness of ultrasound-microwave-assisted heating to augment extraction was also assessed.1-ethyl-3-methylimidazolium-bromide(EMIMBr)resulted in the highest extraction yield of rutin(25.7 mg/g),which is the most abundant compound in the by-product;such a yield was comparable to that achievable via methanol extraction.Ultrasound-microwave-assisted extraction did not show significant improvement in rutin yield when EMIMBr was used.Interestingly,although methanolic extract exhibited slightly higher content of rutin,it also contained the higher number of impurities;EMIMBr extract contained less impurities with higher relative content of rutin(70.9%)than that in methanolic extract(67.7%).This could be a milestone in extraction work for an efficient purification.