scholarly journals Synthesis of glucose esters from cellulose in ionic liquids

Holzforschung ◽  
2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Igor A. Ignatyev ◽  
Charlie Van Doorslaer ◽  
Pascal G.N. Mertens ◽  
Koen Binnemans ◽  
Dirk E. de Vos

Abstract The transformation of cellulose into glucose ester α-d-glucose pentaacetate (GPAc) was carried out in ionic liquid 1-butyl-3-methylimidazolium chloride under mild reaction conditions. The reaction comprises two steps: the first involves a hydrolysis reaction, yielding α-d-glucose and glucose oligomers; and then only after some time, the acetylating reagent acetic anhydride is added. Under optimized conditions and with the acidic resin Amberlyst 15DRY as a hydrolysis catalyst, a 70% yield of GPAc was obtained. This product could be quantitatively isolated by simple liquid-liquid extraction, which allowed easy recycling of the ionic liquid and catalyst.

2020 ◽  
Vol 18 (1) ◽  
pp. 1020-1029
Author(s):  
Shinkichi Nomura ◽  
Yoshiharu Ito ◽  
Shigehiko Takegami ◽  
Tatsuya Kitade

AbstractAlkyl methanesulfonates are genotoxic impurities that should be limited to an intake of not more than 1.5 µg/day, as regulated by the International Council for Harmonization guideline M7. We herein report a trace analysis of methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), and isopropyl methanesulfonate (IPMS) in the delgocitinib drug substance using liquid–liquid extraction, with an ionic liquid as the sample-solving medium, and direct injection gas chromatography detected with a flame-ionization detector. The proposed method takes advantage of the fine solubility of ionic liquids toward the drug substance, the good extraction efficiency of alkyl methanesulfonates in liquid–liquid extraction using the Chem Elut cartridge with low-polar organic solvents, and the ability of alkyl methanesulfonates to concentrate in minimum amounts of organic solvent, resulting in excellent sensitivity and selectivity. Specifically, for the preparation of the sample solution, a mixture of 1-butyl-3-methylimidazolium chloride, water, and acetonitrile was used as the sample-solving media, extracted with diethyl ether, and the eluent was concentrated to 1 mL. The method showed good linearity, accuracy, and precision from 1 to 5 ppm, and the limits of detection of MMS, EMS, and IPMS were 0.1, 0.05, and 0.05 ppm, respectively.


Author(s):  
Ana Carolina Furiozo Arantes ◽  
Kelly Francisco da Cunha ◽  
Marilia Santoro Cardoso ◽  
Karina Diniz Oliveira ◽  
Jose Luiz Costa

Abstract Purpose We developed and validated a method for quantitative analysis of 50 psychoactive substances and metabolites (antidepressants, benzodiazepines and opioids) in oral fluid samples using simple liquid–liquid extraction procedure followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Method Oral fluid samples were collected using Quantisal™ device and extracted by liquid–liquid extraction with 1.0 mL of methyl tert-butyl ether and then analyzed using LC–MS/MS. Results The method attended method validation criteria, with limits of quantification as low as 0.5 and 1.0 ng/mL, and linearity between 0.5–50.0 ng/mL for antidepressants, 0.5–25.0 ng/mL for benzodiazepines and 1.0–50.0 ng/mL to opioids. During method validation, bias and imprecision values were not greater than 16 and 20%, respectively. Ionization suppression/enhancement bias results were not greater than 25%. No evidence of carryover was observed. Sample stability studies showed that almost all analytes were stable at 25 °C for 3 days and at 4 °C for 7 days. Freeze–thaw cycles stability showed that most antidepressants and opioids were stable under these conditions. Autosampler stability study showed that all analytes were stable for 24 h, except for nitrazepam and 7-aminoclonazepam. Thirty-eight authentic oral fluid samples were analyzed; 36.8% of the samples were positive for 2 drugs. Citalopram was the most common drug found, followed by venlafaxine. Conclusions The method was validated according to international recommendations for the 50 analytes, showing low limits of quantification, good imprecision and bias values, using simple liquid–liquid extraction, and was successfully applied to authentic oral fluid samples analysis.


2017 ◽  
Vol 38 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Artur Kubiczek ◽  
Władysław Kamiński

AbstractRoom-temperature ionic liquids (RTILs) are a moderately new class of liquid substances that are characterized by a great variety of possible anion-cation combinations giving each of them different properties. For this reason, they have been termed as designer solvents and, as such, they are particularly promising for liquid-liquid extraction, which has been quite intensely studied over the last decade. This paper concentrates on the recent liquid-liquid extraction studies involving ionic liquids, yet focusing strictly on the separation of n-butanol from model aqueous solutions. Such research is undertaken mainly with the intention of facilitating biological butanol production, which is usually carried out through the ABE fermentation process. So far, various sorts of RTILs have been tested for this purpose while mostly ternary liquid-liquid systems have been investigated. The industrial design of liquid-liquid extraction requires prior knowledge of the state of thermodynamic equilibrium and its relation to the process parameters. Such knowledge can be obtained by performing a series of extraction experiments and employing a certain mathematical model to approximate the equilibrium. There are at least a few models available but this paper concentrates primarily on the NRTL equation, which has proven to be one of the most accurate tools for correlating experimental equilibrium data. Thus, all the presented studies have been selected based on the accepted modeling method. The reader is also shown how the NRTL equation can be used to model liquid-liquid systems containing more than three components as it has been the authors’ recent area of expertise.


2012 ◽  
Vol 33 (1) ◽  
pp. 167-183 ◽  
Author(s):  
Marek Krawczyk ◽  
Kamil Kamiński ◽  
Jerzy Petera

Experimental and numerical investigation of electrostatic spray liquid-liquid extraction with ionic liquids A new concept of an electrostatic spray column for liquid-liquid extraction was investigated. An important problem for separation processes is the presence of azeotropic or close-boiling mixtures in their production, for example heptane with ethanol, since the separation is impossible by ordinary distillation. The use of ionic liquids (IL) as a dispersed solvent specially engineered for any specific organic mixture in terms of selectivity is a key factor to successful separation. As IL present particularly attractive combination of favorable characteristics for the separation of heptane and ethanol, in this work we use 1-butyl-3-methylimidazolium methyl sulfate [BMIM][MeSO4]. Because of high viscosity and relatively high cost of IL a new technique was introduced, consisting in the electrostatically spray generation to enhance the mass transport between the phases. In order to optimally design the geometry of the contactor a series of numerical simulation was performed. Especially multi-nozzle variants for better exploitation of contactor volume were investigated. Experiments showed excellent possibility of control of the dispersion characteristics by applied voltage and thus control of the rate of extraction. The preliminary simulations based on our mathematical model for a three nozzle variant exhibited visual agreement with the theory of electrostatics.


2021 ◽  
Author(s):  
Zenghui Wang ◽  
Pingping Zhao ◽  
Jimin Wu ◽  
Jun Gao ◽  
Lianzheng Zhang ◽  
...  

The design of stable ionic liquids (ILs) has become crucial for efficient liquid-liquid extraction (LLE) of alcohol and water. Porous ionic liquids (PILs), as a special class of ILs, have...


2018 ◽  
Vol 54 (17) ◽  
pp. 2895-2906 ◽  
Author(s):  
Romero Julio ◽  
Carlos Zambra ◽  
Gastón Merlet ◽  
Rene Cabezas ◽  
Gonzalo Correa ◽  
...  

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