• Analytical Science and Technology
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• v.24 no.6
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• pp.467-476
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• 2011

Solubility data of carbon dioxide ($CO_2$) in the imidazolium-based ionic liquids with methylsulfate anion are presented at pressures up to about 45 MPa and at temperatures between 303.15 K and 343.15 K. The ionic liquids studied in this work were 1-ethyl-3-methylimidazolium methylsulfate ([emim][$mSO_4$]), 1-butyl-3-methylimidazolium methylsulfate ([bmim][$mSO_4$]). The solubilities of $CO_2$ were determined by measuring the bubble point or cloud point pressures of the binary mixtures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The equilibrium pressure increased very steeply at high $CO_2$ compositions. The $CO_2$ solubility in ionic liquids increased with increase of the total length of alkyl chains attached to the imidazolium cation of the ionic liquids. The phase equilibrium data for the $CO_2$ + ionic liquid systems have been correlated using the Peng-Robinson equation of state.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.6
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• pp.477-483
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• 2006

Ionic liquids in the form of organic salts are being widely used as new solvent media. In this paper three positional isomers, o-amino benzoic acid, m-amino benzoic acid, and p-amino benzoic acids were separated with four different ionic liquids as mobile phase additives using high performance liquid chromatography (HPLC). The following ionic liquids were used: 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][$BF_{4}$]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][$BF_{4}$]), 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), and 1-octyl-3-methylimidazolium methylsulfate ([OMIm][MS]). The effects of the alkyl group length on the imidazolium ring and its counterion, and the concentrations of the ionic liquids on the retention factors and resolutions of amino benzoic acid isomers were tested. The results of the separations with ionic liquids as the eluents were better than those without ionic liquids. Excellent separations of the three isomers were achieved using 2.0-8.0 mM/L [OMIm][MS] and 1.0-8.0 mM/L [EMIm][MS] as the eluent modifiers.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.93-97
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• 2010

Polyaniline doped with ionic liquid (1,3-dimethylimidazolium methylsulfate, I-DMS) soluble in polar solvents (NMP, DMSO, DMF, m-cresol etc.) were synthesized by nucleophilic addition. Solubilities of PAN/I-DMS powder in polar solvents were observed in the range of 3~6 wt%/vol., respectively. The electrical conductivities of PAN/I-DMS films appeared in the range of $10^{-2}{\sim}7S/cm$. Polyaniline doped with I-DMS (PAN/I-DMS) showed improved thermal stability and conductivity compared to that of HCl doped polyaniline (PAN/HCl) and dimethylsulfate (DMS) doped polyaniline (PAN/DMS) upon heat treatment at $160^{\circ}C$. These improved conductivity and solubility in organic polar solvents was explained with the interactions between the polar sulfonate group and polar solvents.

• Korean Journal of Veterinary Research
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• v.54 no.1
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• pp.59-62
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• 2014

A 12-year-old, castrated male Yorkshire terrier dog presented with frequent regurgitations that had begun 45 days earlier and become more progressive. Radiographs revealed an air-trap region behind the cranial esophageal sphincter muscle in the esophagus and esophagographies with barium contrast showed mild esophageal dilation with decreased motility. Esophageal motility increased within 5 min of neostigmine methylsulfate administration and acetylcholine receptor antibodies titer increased to beyond the normal range. Based on these findings, acquired myasthenia gravis with focal form was diagnosed, making this the first such case diagnosed by an acetylcholine receptor antibody test in Korea.

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.107-111
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• 2012

Three dogs (An 8 years-old intact female Poodle, a 7 years-old intact male Schunauzer, and an 8 yearsold Golden Retriever) were presented due to acute vomiting, dyspnea, and generalized weakness. Megaesophagus was confirmed through radiographic examination in all 3 dogs. Relative oesophageal diameter (ROD) was measured and results of ROD measurements showed the possibility of megaesophagus secondary to myasthenia gravis in three dogs. Thus we performed anticholinesterase test as screening test for myasthenia gravis. In all three dogs, esophageal diameter was reduced after neostigmine methylsulfate administration. For definite diagnosis of acquired myasthenia gravis, serum acetylcholine receptor antibody titer was measured, but definite diagnosis was confirmed only in one case. However, based on history, radiographic findings, anticholinesterase test, ROD measurement, other two cases were still suspected as megaesophagus secondary to myasthenia gravis. Treatment with pyridostigmine bromide was initiated in all dogs, and improvement of esophageal diameter was shown in all dogs. One dog was successfully managed for 15 months after initial treatment and, is still alive, but other two dogs were died shortly after initial treatment, because of severe aspiration pneumonia.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.601-606
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• 2007

The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.

• Journal of Microbiology and Biotechnology
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• v.19 no.7
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• pp.713-717
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• 2009

The dependence of the catalytic properties of horseradish peroxidase on the structural changes of ionic liquids was investigated with two water-miscible ionic liquids, N-butyl-3methypyridinium tetraftuoroborate ([$BMP_y$][$BF_4$]) and 1-butyl-3-methylimidazolium methylsulfate ([BMIM][$MeSO_4$]), each of which shares an anion ($BF_4^-$) or a cation ($BMIM^+$) with 1-butyl-3-methylimidazolium tetraftuoroborate ([BMIM][$BF_4$]), respectively. The oxidation of guaiacol (2-methoxyphenol) with $H_2O_2$was used as a model reaction. In order to minimize the effect of solution viscosity on the kinetic constants of the enzymatic catalysis, the enzymatic reactions for the kinetic study were performed in water-ionic liquid mixtures containing 25% (v/v) ionic liquid at maximum. Similarly to the previously reported results for [BMIM][$BF_4$], as the concentration of [$BMP_y$][$BF_4$] increased, the $K_m$value increased with a decrease in the $k_{cat}$value: the $K_m$value increased markedly from 2.8 mM in 100% water to 12.6 mM in 25% (v/v) ionic liquid, indicating that ionic liquid significantly weakens the binding affinity of guaiacol to the enzyme. On the contrary, [BMIM][$MeSO_4$] decreased the Km value to 1.4 mM in 25% (v/v) ionic liquid. [BMIM][$MeSO_4$] also decreased $k_{cat}$more than 3-folds [from 13.8 $s^{-1}$in 100% water to 4.1 $s^{-1}$in 25% (v/v) ionic liquid]. These results indicate that the ionic liquids interact with the enzyme at the molecular level as well as at a macroscopic thermodynamic scale. Specifically, the anionic component of the ionic liquids influenced the catalysis of horseradish peroxidase in different ways.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.1
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• pp.49-55
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• 2008

The feasibility of ionic liquid as a novel absorbent of $SO_2$ for the separation of $SO_2$ from $SO_2/O_2$ mixture in the thermochemical IS(Iodine-Sulfur) cycle was investigated. 1,3-dimethylimidazolium methylsulfate ([DMIm]$MeSO_4$) had shown twenty five times higher solubility of $SO_2$ than that of $O_2$. The dependence of $SO_2$ solubility by [DMIm]$MeSO_4$ on temperature and $SO_2$ partial pressure was examined, which confirmed the possibility of temperature and pressure swing for the separation process. Through cyclic absorption and desorption with temperature swing the stability of [DMIm]$MeSO_4$ in the separation process was also demonstrated. As a result of the experiments carried out, $SO_2$ separation from $SO_2/O_2$ mixture with ionic liquid([DMIm]$MeSO_4$) can be applied to the thermochemical IS cycle.