scholarly journals Removal of Pyridine, Quinoline, and Aniline from Oil by Extraction with Aqueous Solution of (Hydroxy)quinolinium and Benzothiazolium Ionic Liquids in Various Ways

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 216
Author(s):  
Zhaojin Zhang ◽  
Yinan Li ◽  
Jing Gao ◽  
Alula Yohannes ◽  
Hang Song ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
Water Mass ◽  
Solid Phase ◽  
Kinetic Equations ◽  
Extraction Process ◽  
Structural Features ◽  
Back Extraction ◽  
Mass Ratio ◽  
N Removal

Based on above background, quinolinium, 8-hydroxy-quinolinium, and benzothiazolium ionic liquids, containing the acidic anions of methanesulfonate ([CH3SO3]−), phosphate ([H2PO4]−), p-toluenesulfonate ([p-TSA]−), and bisulfate ([HSO4]−) were synthesized. After comparison, the aqueous solution of benzothiazole bisulfate [HBth][HSO4] was selected as the most ideal extractant for removing pyridine and aniline. Meanwhile, benzothiazole bisulfate [HBth][HSO4] solution was found as the best one for removing quinoline from simulated oil. Then, the single stage extraction and two-step extraction were used in the extraction for the simulated oil containing pyridine, quinoline or aniline, and their mixture, respectively. Their denitrogenation performance on their N-removal effect was compared on the basis of structural features, and main extraction conditions were further investigated, including mass ratio of IL to water, mass ratio of IL to oil, and temperature. Furthermore, the extraction process was described by two kinetic equations. Recovery and reuse of IL were realized by back-extraction and liquid-liquid separation, and a related mechanism was speculated, according to all the experimental results. Finally, based on the developed method for preparing complex adsorbent tablets, corresponding immobilized IL was used to remove target objects, by solid phase extraction, in order to extend separation ways, which was more easily recovered after extraction.

scholarly journals Cooking and drying process optimisation of shea (Butyrospermum parkii) butter extraction

2014 ◽  
Vol 32 (No. 6) ◽  
pp. 578-584 ◽  
Author(s):  
S.N. Dongmo ◽  
H.M. Womeni ◽  
F.T. Mbiapo ◽  
M. Linder ◽  
J. Fanni ◽  
...  
Keyword(s):  
Peroxide Value ◽  
Water Mass ◽  
Fatty Acid Content ◽  
Extraction Process ◽  
Extraction Yield ◽  
Cooking Time ◽  
Shea Butter ◽  
Mass Ratio ◽  
Drying Time ◽  
Drying Temperature

Cooking and drying conditions of the shea butter extraction process were determined using a response surface methodology. The influence of cooking time, temperature, and nuts/water mass ratio, drying time, and temperature on the content of free fatty acids, the peroxide value, as well as on the extraction yield was investigated. Results showed that both the free fatty acid content and the peroxide value were significantly affected by cooking and drying temperature; the cooking time and nuts/water ratio also affected significantly the peroxide value. Increasing cooking and drying temperature reduced the FFA content but contributed to increase the peroxide value. The cooking and drying temperature range of 75–80°C and < 54°C, respectively; cooking time of 70–100 min; drying time < 40 h, and cooking nuts/water mass ratio < 400 g/l of water were found to be optimum conditions for the extraction of shea butter.  

Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy

2020 ◽  
Vol 16 (5) ◽  
pp. 748-756
Author(s):  
Mir Waqas Alam ◽  
Tentu Nageswara Rao ◽  
Yarasani Prashanthi ◽  
Vourse Sridhar ◽  
Adil Alshoaibi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Silica Nanoparticles ◽  
Solid Phase ◽  
Silica Nanoparticle ◽  
Environmental Water ◽  
Phase Extraction ◽  
Functionalized Nanoparticles ◽  
Supporting Material

Background: Herbicides are very beneficial in the crop yield with the aid of controlling weeds within the agriculture, but several herbicides are chronic in soil. Objective: In this study, nanoparticles and the packages of synthesized novel silica nanoparticles were studied for the preconcentration of herbicides. Methods: These nanoparticles prepared by the Stöber mechanism were purified and functionalized. Nanoparticles thus prepared successfully were used as supporting material for the preconcentration of residues of herbicides in the water. Results: Preconcentration was achieved by preparing the silica-based solid-phase-extraction cartridges. Nanoparticles used for this purpose were within the range of 50-250 nm. An SPE cartridge was prepared by packing 200 mg of silica nanoparticle in the empty cartridge of diameter 5.5 cm and length 0.6 cm in between PTFE frits. Aqueous solutions of 0.1 μg/ml of herbicides were prepared separately, and 10 ml of the solution was passed through the cartridge at the rate of 0.2 ml/min. After passing 10 ml volume of the aqueous solution, residues adsorbed on the cartridge were eluted using 2 ml of acetonitrile. The eluate was injected to determine the herbicide residue adsorbed on the SPE cartridge. Conclusion: In the study, it was found that greater than 90% of the herbicide residues were trapped on silica nanoparticle-based SPE cartridge. An analytical method was developed for the simultaneous determination of these herbicides. The residues were quantified by LC-MS/MS with ESI mode.

Synthesis of four new V1 antagonists of arginine-vasopressin (AVP) containing new thioacids at position 1 and their vasoconstrictor activity towards isolated mesenteric arterial vessels of rats

1991 ◽  
Vol 56 (2) ◽  
pp. 491-498 ◽  
Author(s):  
Bernard Lammek ◽  
Izabela Derdowska ◽  
Tomasz M. Wierzba ◽  
Witold Juzwa
Keyword(s):  
Peptide Synthesis ◽  
Arginine Vasopressin ◽  
Solid Phase ◽  
Structural Features ◽  
Phase Method ◽  
Competitive Antagonist ◽  
Vasoconstrictor Effect ◽  
Solid Phase Method

In an attempt to determine some of the structural features in position 1 that account for V1 antagonism, four new analogues of arginine-vasopressin were synthesized and the effect of the modifications on the vasoconstrictor activity was checked using isolated mesenteric arterial vessels of rats. The protected precursors required for these analogues were synthesized by a solid phase method of peptide synthesis. One of the reported analogues, namely [1-(4-mercapto-4-tetrahydrothiopyraneacetic acid)., 2-O-methyltyrosine, 8-arginine]vasopressin appears to be a potent competitive antagonist of the vasoconstrictor effect by AVP.

scholarly journals Quantitative and Qualitative Analysis of Some Inorganic Compounds by Raman Spectroscopy

1994 ◽  
Vol 48 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Daniel R. Lombardi ◽  
Chao Wang ◽  
Bin Sun ◽  
Augustus W. Fountain ◽  
Thomas J. Vickers ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Qualitative Analysis ◽  
Raman Spectra ◽  
Solid Phase ◽  
Inorganic Compounds ◽  
Core Material ◽  
Storage Tanks ◽  
Hanford Site ◽  
Sampling Probe

Raman spectra have been measured for a number of nitrates, nitrites, sulfates, ferrocyanides, and ferricyanides, both in the solid phase and in aqueous solution. Accurate locations of peak maxima are given. Limits of detection for some of the compounds are given for solutions and for solid mixtures in NaNO3. Preliminary measurements have been made on core material recovered from the storage tanks on the Hanford site in Richland, Washington. Representative spectra are presented, showing that it is possible to observe responses of individual components from measurements made directly on untreated cores, with the use of a fiberoptic sampling probe.

scholarly journals Magnetic Steel Slag Biochar for Ammonium Nitrogen Removal from Aqueous Solution

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2682
Author(s):  
Gyuhyeon Kim ◽  
Young-Mo Kim ◽  
Su-Min Kim ◽  
Hyun-Uk Cho ◽  
Jong-Moon Park
Keyword(s):  
Aqueous Solution ◽  
Magnetic Properties ◽  
Low Cost ◽  
Steel Slag ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Biochar ◽  
N Removal ◽  
Magnetic Steel ◽  
Slag Waste

In this study, magnetic steel slag biochar (MSSB) was synthesized from low-cost steel slag waste to investigate the effectiveness of steel slag biochar composite for NH4-N removal and magnetic properties in aqueous solution. The maximum adsorption capacity of NH4-N by MSSB was 4.366 mg/g according to the Langmuir model. The magnetic properties of MSSB indicated paramagnetic behavior and a saturation magnetic moment of 2.30 emu/g at 2 Tesla. The NH4-N adsorption process was well characterized by the pseudo-second order kinetic model and Temkin isotherm model. This study demonstrated the potential of magnetic biochar synthesized from steel slag waste for NH4-N removal in aqueous solution.

scholarly journals Structure-Acid Lability Relationship of N-alkylated α,α-dialkylglycine Obtained via a Ugi Multicomponent Reaction

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 197
Author(s):  
Iván Ramos-Tomillero ◽  
Marisa K. Sánchez ◽  
Hortensia Rodríguez ◽  
Fernando Albericio
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Structural Features ◽  
Amide Bond ◽  
Acidic Media ◽  
Phase Synthesis ◽  
Acyl Chains ◽  
Cyclic Compounds ◽  
Relationship Of ◽  
Fine Tune

Using the classical Ugi four-component reaction to fuse an amine, ketone, carboxylic acid, and isocyanide, here we prepared a short library of N-alkylated α,α-dialkylglycine derivatives. Due to the polyfunctionality of the dipeptidic scaffold, this highly steric hindered system shows an interesting acidolytic cleavage of the C-terminal amide. In this regard, we studied the structure-acid lability relationship of the C-terminal amide bond (cyclohexylamide) of N-alkylated α,α-dialkylglycine amides 1a–n in acidic media and, afterward, it was established that the most important structural features related to its cleavage. Then, it was demonstrated that electron-donating effects in the aromatic amines, flexible acyl chains (Gly) at the N-terminal and the introduction of cyclic compounds into dipeptide scaffolds, increased the rate of acidolysis. All these effects are related to the ease with which the oxazolonium ion intermediate forms and they promote the proximity of the central carbonyl group to the C-terminal amide, resulting in C-terminal amide cleavage. Consequently, these findings could be applied for the design of new protecting groups, handles for solid-phase synthesis, and linkers for conjugation, due to its easily modulable and the fact that it allows to fine tune its acid-lability.

scholarly journals COSMO-RS prediction and experimental verification of 1,5-pentanediamine extraction from aqueous solution by ionic liquids

2020 ◽  
Author(s):  
Chenhao Jiang ◽  
Hongye Cheng ◽  
Zexian Qin ◽  
Ruizhuan Wang ◽  
Lifang Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
Experimental Verification
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