Type Of Organic Solvent Research Articles

Solvents Triggered Coil-to-Globule-to-Coil Transition of Dual Nanocomposite Hydrogels with Inorganic Hybrid Crosslinking

This paper presents the study on the reentrant solvation of dual nanocomposite hydrogel poly-N-isopropylacrylamide/Laponite/SiO2 (PNIPAM/Laponite/SiO2) upon shrinkage/reswelling process. Depending on the unique hierarchical microstructure of inorganic hybrid crosslinking of Laponite and SiO2, as well as the preferential interaction of polar solvents with PNIPAM chains, the hydrogel exhibited rapid coil-to-globule-to-coil transition in water-polar solvent mixtures. The solvation behavior could be controlled through varying types of organic solvents. Shrinkage in water-polar solvent mixtures occurred as a consequence of strong interaction between polar solvents and PNIPAM chains, whereas reswelling resulted from the direct interaction of the solvent molecules with the intermolecular water in the hydrogel. The attractive competing effects on forming hydrogel-water and hydrogel-polar solvent hydrogen bonds were considered to be indis-pensable to the solvation. The rapid response rate was attributed to the synergistic effect of the unique hetero-geneous microstructure with inorganic hybrid crosslinking and preferential interaction of polar solvents with polymer chains. The mechanism proposed in this paper provides a new reference on design of smart soft mat-ter systems. Moreover, several solvation effects described in this paper can be incorporated in theory of cononsolvent-induced conformational transitions in the nanocomposite hydrogels with inorganic hybrid crosslinking.

A simple and rapid determination of Al(III) in natural water samples using dispersive liquid-liquid microextraction after complexation with a novel antipyrine-based Schiff base reagent.

The purpose of this study is the development of a novel strategy for the determination of Al3+ ions using the combination of dispersive liquid-liquid microextraction(DLLME)andUV-Vis spectrophotometry. The method is grounded in the complexation between a novel antipyrine-based Schiff base reagent (EHMP) and Al3+ ions. Aluminum concentrations were detected using UV-Vis spectrophotometry at 260nm and this technique was optimized using the absorbance value of EHMP-Al complex. pH, mixing period, type and volume of organic solvent, etc. were optimized stepwise in order to find out optimum experimental conditions. The limit of detection and the limit of quantification values for the improved analytical method were to be estimated 0.31 and 1.03μmol.L-1, respectively. The new strategy was successfully performed to define Al3+ ions in natural water samples with RSD values (84.01-107.71%) and recovery values (0.01-0.09%).

Capillary electrophoresis-mass spectrometry as a tool for the noninvasive target metabolomic analysis of underivatized amino acids for evaluating embryo viability in assisted reproduction.

Monitoring metabolite uptake and excretion in the culture medium is a noninvasive technique that is used for the metabolic study of cleaving embryos after in vitro fertilization. Low sample consumption, the versatility of the detection, and optimal sensitivity and selectivity are essential elements for extracellular metabolome analyses, and can be conveniently achieved by combining CE with mass spectrometric detection. This paper reports a method for amino acid determination in a limited volume sample (8 μL)ofspent culture media collected after the cultivation of in vitro fertilized embryos. Special attention was focused on the sample preparation procedure. The sample was processed with acetonitrile, which facilitates online sample preconcentration via field-amplified sample stacking, and undesired sample evaporation was significantly reduced by the simultaneous addition of dimethyl sulfoxide. Key parameters that affected electrophoretic separation and mass spectrometric detection were investigated, including the type of buffers and organic solvent, optimization of their concentrations, and finally the settings for their ionization. The separation and quantification of 19 amino acids were achieved using 15% acetic acid as the background electrolyte with a sheath liquid consisting of an equimolar mixture of methanol and water. The applicability of the optimized system was demonstrated by determining the amino acid profile in 40 samples of spent cultivation medium in this pilot study. This developed method also has great potential for amino acid analyses in minute sample volumes of other biological matrices.

Development of a fast, online three-phase electroextraction hyphenated to fast liquid chromatography–mass spectrometry for analysis of trace-level acid pharmaceuticals in plasma

Sample preparation is a challenge for high-throughput analysis, especially for volume-limited samples with low-abundant analytes. Ideally, sample preparation enriches the analytes of interest while removing the interferents to reduce the matrix effect and improve both sensitivity and quantification. In this study, a three-phase electroextraction (EE) method hyphenated to fast online liquid chromatography–mass spectrometry (LC-MS) was developed. Four model acidic drugs of relevance for drug monitoring in plasma, i.e. naproxen, fenoprofen, flurbiprofen, and ibuprofen, were utilized for the optimization and evaluation of the method. A Design of Experiment approach (Box-Behnken design) was used to optimize the critical parameters of the method, i.e., the type of organic solvent, pH of the sample and acceptor phase, and the extraction voltage and time. Good fitness (P < 0.02, R2 > 0.95) was observed for the developed quadratic model. Extraction could be achieved in less than 2 min (115 s) with enrichment factors (EF) up to 190 and extraction recoveries (ER) up to 38% for academic samples. Additionally, the optimized three-phase EE method was successfully applied to spiked plasma samples with low-abundant (50 ng mL−1) analytes and a low sample volume of 15 μL plasma in 10-fold diluted samples. Finally, two crucial contributors to the matrix effect of three-phase EE application on plasma samples were determined. Specifically, the ion-suppression effect in the MS source was reduced by the fast LC separation, and the matrix effect during extraction was negligible for the diluted protein-precipitated plasma samples. The developed three-phase EE method is easy to operate and provides fast and online extraction of trace-level acidic analytes from volume-limited biological samples. Therefore, this method can provide a potential solution for sample-preparation bottlenecks in high-throughput bioanalysis workflows.

HIGH VALUED LIMONENE IN ESSENTIAL OIL EXTRACT FROM LIME PEEL WASTE FOR PARFUM INDUSTRY

Limonene in essential oils is highly valuable attracts great interest of consumers due to its specific fragrance. It is not surprising that many big perfume industries are looking for high purified limonene found in essential oils of certain fruits and flowers. This study investigates the extraction process of essential oil from lime peel waste. This study has used two extraction methods, i.e. maceration method and Soxhlet technique. Two types of organic solvent applied, i.e. hexane and ethanol. This work studies the effect of extraction time, type of organic solvent, and extraction method on yield of extraction. Characterization studies as FTIR (Fourier Transform Infra Red) Spectroscopy related to type of chemical bonding of limonene in essential oil and GC-MS (Gas Chromatography – Mass Spectrometry) related to limonene fragmentation have also investigated.

Organic Solvent Nanofiltration of Water-in-Oil Pickering Emulsions-What Influences Permeability?

Pickering emulsions (PEs) have received increasing interest for their application in catalytic multiphase reactions. Organic solvent nanofiltration of PEs was shown to be a promising procedure for efficient and effective catalyst recycling. In this work, a systematic parameter study to identify the main influencing parameters on PE filtration was conducted for a large variety of PE compositions for the first time. In addition to temperature, only the type of organic solvent significantly influenced the filtration performance, which could be mathematically modeled via a combination of the solution–diffusion and the resistance in the series model. Particle type and concentration, dispersed phase fraction and the presence of reaction (by-)products did not show any significant impact on the permeability. The stirrer speed only became important when emulsions stabilized by particles without the tendency to form 3D network structures were filtered in long-term filtration experiments. These results pave the way towards the application of PE membrane filtration for catalyst recovery in continuous liquid/liquid multiphase reactions and enable broad operation windows. As the mechanical separation of PEs was shown to be a very robust process, the emulsion composition can now be tuned to meet the needs of the reaction without any (significant) loss in filtration performance.

Controlling the geometric design of anodic 1D TiO2 nanotubes for the electrochemical reduction of 2,4,6-trinitrotoluene in ambient conditions

In this study, we investigated how the geometric design of anodic one-dimensional (1D) TiO2 nanotube arrays affected their performance in the electrochemical reduction of 2,4,6-trinitrotoluene (2,4,6-TNT) in aqueous solutions and ambient conditions. Two main geometric parameters were considered: the inner diameter and length of TiO2 nanotubes. The various TiO2 nanotubes were fabricated using an anodization technique performed in four types of fluoride-containing organic solvents by adjusting various anodization parameters. All as-prepared samples successfully detected 2,4,6-TNT in an aqueous solution using cyclic voltammetry and linear sweep voltammetry. Three peaks corresponding to the reduction of each nitro group in 2,4,6-TNT were observed between − 0.5 and − 1.0 V (versus Ag/AgCl, 3 M KCl). Further, we discovered that nanotube length affected 2,4,6-TNT reduction performance. We also performed experiments at various concentrations of 2,4,6-TNT and determined the sensitivity to be 1.78 × 10-3 mA cm−2 ppm−1, the limit of detection to be 6.49 ppm, and the limit of quantitation to be 21.6 ppm 2,4,6-TNT over a linear range of 20 – 100 ppm using an electrode with nanotube inner diameter of 75 nm and length of 6 µm. A simple and fast fabricated composite-free 1D TiO2 nanotube arrays electrode can form the basis for future studies in enhancing the detection sensitivity. Electrochemical detection of other nitro-based compounds, such as nitroglycerin, nitrocellulose, picric acid, and their mixtures, require further investigation.

Bioprospection of Enggano Macroscopic Fungi as Antibacterial and Antioxidant Agents

Macrofungi in Indonesia have not been widely studied for their pharmacological activity, especially as a source of antibacterial and antioxidant properties, even though Indonesia as a tropical country has quite a high diversity of macrofungi. This study aims to reveal the potential of macrofungi from the Enggano forest as a source of antibacterial and antioxidant compounds. Four types of macrofungi were collected and their metabolites were extracted using four types of organic solvents. Antibacterial and antioxidant activity assay of the extract was carried out using the TLC Bioautography method. From the sixteen macrofungal extracts, there is one extract that has the strongest antibacterial activity compared to the others, namely n-hexane Coriolopsis polyzona. It showed moderate antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values of 256–128 μg/mL, respectively. Meanwhile, the antioxidant activity of the macrofungal extracts showed weak activity with IC50 values of 3080–7370 μg/mL (AAI values of 0.033–0.079).

Effect of Organic Solvents on the Structure and Activity of a Minimal Lipase.

Lipases are ubiquitously used in chemo-enzymatic synthesis and industrial applications. Nevertheless, the modulation of the activity of lipases by organic solvents still is not fully understood at the molecular level. We systematically investigated the activity and structure of lipase A from Bacillus subtilis in binary water-organic solvent mixtures of dimethyl sulfoxide (DMSO), acetonitrile (ACN), and isopropyl alcohol (IPA) using activity assays, fluorescence spectroscopy, molecular dynamics (MD) simulations, and FRET/MD analysis. The enzymatic activity strongly depended on the type and amount of organic solvent in the reaction media. Whereas IPA and ACN reduced the activity of the enzyme, small concentrations of DMSO led to lipase activation via an uncompetitive mechanism. DMSO molecules did not directly interfere with the binding of the substrate in the active site, contrary to what is known for other solvents and enzymes. We propose that the His156-Asp133 interaction, the binding of organic molecules to the active site, and the water accessibility of the substrate are key factors modulating the catalytic activity. Furthermore, we rationalized the role of solvent descriptors on the regulation of enzymatic activity in mixtures with low concentrations of the organic molecule, with prospective implications for the optimization of biocatalytic processes via solvent tuning.

Design and optimization of sensitive analytical spectrophotometric method for micro determination of copper(II) from e-waste by using of novel chromogenic extractant

In this article, a novel spectrophotometric reagent 1-(pyrimidine)-4, 4, 6-trimethyl-1,4-dihydropyrimidine-2-thiol [PTPT] has been synthesized for liquid–liquid extraction and spectrophotometric determination of copper(II). The as-synthesized ligand has been selectively forms stable complex with copper(II) in basic medium (pH 9.0), in presence of mild pyridine the extraction and color stability has found to be synergistically enhanced. The equilibrium time is 10 min for effective extraction of copper(II) from organic phase and absorbance of colored organic complex in carbon tetrachloride is measured spectrophotometrically at λmax 615 nm against reagent blank. The ternary complex of Cu(II)-PTPT-Py having molar ratio 1:2:2 (M:L:Py) showed green colored complex. The main factors influencing the achievement of synergistic extraction; i.e. pH, ligand concentration, type and volume of the dispersive organic solvents, equilibrium time, synergent concentration and foreign ions were investigated.The Beer’s law was obeyed in the concentration range 1–20 μg mL−1 of copper(II) and optimum concentration range is evaluated by Ringbom’s plot and it is found that 2.5–25 μg mL−1. In presence of pyridine, molar absorptivity and Sandell’s sensitivity of copper(II)-PTPT complex is 2.80 × 103 L mol−1 cm−1 and 0.226 μg cm−2, respectively and in absence of pyridine, molar absorptivity and Sandell’s sensitivity of copper(II)-PTPT complex is 1.35 × 103 L mol−1 cm−1 and 0.469 μg cm−2, respectively. The stoichiometry of the copper(II)-PTPT-pyridine complex was calculated by slope ratio method, mole ratio method and Job’s method of continuous variation and it has been found as 1:2:2. No significant effects of potentially interfering species i.e. cations and anions were observed. The optimized method was applied for the determination of copper(II) in binary, synthetic mixtures and successfully applied for determination of copper(II) from e-waste samples. The standard deviation (R.S.D.) is 0.11% for n = 5 repetition. The reliability of the developed method is confirmed by comparison of experimental results with atomic absorption spectrophotometer.

The effects of Curcuma longa L. leaf extracts on the prevention of oxidation in soybean oil.

The use of natural plant antioxidants has been an alternative approach to synthetic antioxidants for food applications. This study investigated the antioxidant properties of the leaves of Curcuma longa L. against the oxidation of soybean oil using leaf extracts obtained from seven different types of organic solvents and compared to the action of efficient synthetic antioxidants which are widely used and low cost but with toxicity risk. The application of natural alternatives from sources still little studied is a proposal and the extraction of compounds with high antioxidant capacity may vary according to the type of solvent, its mixture, its polarity and other factors that burden or harm the health of the consumer. The leaf extracts were sanitized, dried, and obtained for solvent selection. The quantification of total phenolic compounds (TPC) and antioxidants was performed by using different combinations and proportions of solvents: water (100%), ethanol (100%), methanol (100%), ethanol/water (70%:30%), methanol/water (70%:30%), methanol/acetic acid (99.5%:0.5%), and acetone/water/acetic acid (70%:28:2%). The solvent selected was the one that extracted the highest content of phenolic and antioxidant compounds (using the free radical DPPH scavenging method and FRAP assay). It used an accelerated storage test and experimental design to assess oxidative stability (using peroxide index (PI), thiobarbituric acid reactive substances (TBARS), dienes (DC) and triple conjugates (TC) and statistical analysis). The ethanol/water solvent was efficient in the extraction of TPC (2422 mg GAE 100 g-1). The mixture of solvents extracted an average of 23.65% more TPC when compared to the single solvents. Regarding the antioxidant capacity, the ethanol/water solvent showed 1847 mg TE 100 g-1 using the DPPH and 217 μmol of FeSO4 100 g-1 using the FRAP assays. In addition, the oxidation of soybean oil was delayed by the accelerated storage test showing equivalent results to BHT at 0.02% for the values of PI, TBARS and DC/TC. The E/W extract showed the highest yield in the extraction of phenolic compounds and is a safe solvent for food. The addition of Curcuma longa L. leaf extract to soybean oil caused reductions in PI, TBARS, CD and CT values. The leaf extract of C. longa L. is considered to be a good alternative to synthetic antioxidants against the oxidative degradation of soybean oil.

Study on the Gel Cleaning System for Removal of Poly (vinyl acetate) Fixative of the Mural Paintings of the Payathonzu Temple in Bagan, Myanmar (I) - Focusing on Properties and Removability of Gel Cleaners -

In the past, PVAc [poly(vinyl acetate)] was used as a fixative for the conservation of the murals in the murals of the Payathonzu temple located in Bagan, Myanmar. In this study, attention was paid to gel cleaning as a method for stably removing such PVAc fixatives. Based on the recent research trend related to the cleaning of murals in Bagan ruins, 3 types of gelling agents (Nevek&lt;sup&gt;®&lt;/sup&gt;, Laponite&lt;sup&gt;®&lt;/sup&gt;RD, Carbopol&lt;sup&gt;®&lt;/sup&gt;980) and 2 types of organic solvents (Acetone, Dimethyl carbonate) were selected. Six types of gel cleaners were prepared by mixing gelling agents and organic solvents, and the properties and fixative removability of these cleaners were compared. As a result of confirming the properties of the prepared gel cleaners, the pH of the cleaners was all in the weak acidic to weakly alkaline range, which was a stable condition for mural application. Also, there was no difference in the viscosity of the cleaners depending on the type of solvent, but there was a difference depending on the type of gelling agent used. Regarding the weight loss ratio of PVAc, which is an indicator of removability, the exposure conditions of the gel cleaners, the boiling point of the solvent used, and the viscosity of the gelling agent acted as factors affecting. As a result of comparing the removability of gel cleaners, it was confirmed that the solvent’s fixative solubility, the volatility of the solvent itself, and the solvent release control properties of the gelling agent had a great effect on the removability of the gel cleaners. In Part 2, the stability and the running applicability of the gel cleaners will be investigated by making mockup samples reflecting the properties of the materials and techniques used to produce the mural paintings in the Payathonzu Temple.

Organic Solvent Sensors Using Polymer-Dispersed Liquid Crystal Films with a Pillar Pattern.

An organic solvent sensor of polymer-dispersed liquid crystals (PDLCs) film is fabricated by a combination of tri-functional monomers and LCs. When the patterned PDLC film comes into contact with the organic solvent, the organic solvent will penetrate into the film to induce the orientation of the liquid crystals, which will change from an ordered to a disordered state, which causes the PDLC film to scatter incident light. The experiment used acetone and ethanol as the organic solvents of interest. The results show that the patterned PDLC film has a stronger response to acetone than to ethanol. Based on the difference in the intensity of light scattering and the response time of the patterned PDLC film to different organic solvents, the results can be used to identify and recognize different types of organic solvents.

Dechlorination of landfill poly(vinyl chloride) waste and estimation of recovered chlorine

The wet treatment process was used for the dechlorination of poly(vinyl chloride) (PVC) landfill waste plastic, and the process has shown dependence on concentration of alkali. The process of dechlorination of PVC has shown dependence on the concentration of the alkaline solution and the type of organic solvent used in the preparation of the alkaline solution. Ethylene glycol (EG), diethylene glycol (DEG), and tetraethylene glycol (TEG) are the diols that have been investigated. Moreover, the temperature of the PVC dechlorination process and the time of the PVC solution reflux showed effects on the final degree of the dechlorination (DD%). These were calculated using the Mohr method, where the chloride ions were titrated with a standard solution of silver nitrate in the presence of chromate ions. The study shows that 1 M NaOH/TEG alkaline solution was the best to dechlorinate PVC waste with the wet treatment process at 160 ̊c and for 3 h reflux and the process reclaimed poly(vinyl alcohol) PVA as the main product according to the hydroxyl group substitution mechanism (SN2), besides a few units according to the hydrogen chloride elimination mechanism (E2) with a few remaining chlorinated chains after analysis.

Solvent-free processing of eco-friendly magnetic and superhydrophobic absorbent from all-plant-based materials for efficient oil and organic solvent sorption

The unique features of bioresources such as cellulose and bio-wax include renewability, biodegradability, low cost, and abundance on Earth. Therefore, their efficient use is essential for a sustainable economy. Herein, we report a facile method for the surface modification of pretreated cotton with a bio-wax emulsion in water and Fe3O4 nanoparticles to fabricate a green, durable, magnetic, and superhydrophobic/superoleophilic absorbent for the sorption of oil and organic solvents. Magnetic superhydrophobic cotton (MSC) was successfully prepared via a simple two-step dip-coating method without using any toxic organic reagents. The as-prepared MSC was used to selectively absorb various types of oils and organic solvents up to approximately 20–50 times its own weight. Furthermore, it exhibited a stable magnetic responsivity and high reusability in oil/water separation cycles. In addition, the removal and collection of the absorbed oil/organic solvents were easily achieved with distillation and a vacuum air pump. Moreover, the as-prepared MSC was used in a heavy oil/water gravity-separation filter system and in the continuous collection of a light oil from water surfaces using a pump. The proposed concept may provide a green and sustainable strategy for fabricating superhydrophobic/superoleophilic materials for efficient sorption of oils and organic solvents.

Quantitative analysis of nine isoflavones in traditional Chinese medicines using mixed micellar liquid chromatography containing sodium dodecylsulfate/β-cyclodextrin supramolecular amphiphiles.

Isoflavone is one of the phytoestrogens that have estrogenic effects, so it is usually served as an active ingredient for quality control of traditional Chinese medicines rich in isoflavones. Nine isoflavones commonly found in traditional Chinese medicines were separated in 30 min using mixed micellar liquid chromatography. The mobile phase consisted of 0.08 M sodium dodecylsulfate and 6.05 mM β-cyclodextrin:methanol (87:13, v/v) at pH 3 and eluted isocratically at 1 mL/min through a C18 column. In this study, we systematically optimized the chromatographic conditions including the pH, the composition and concentration of surfactants, the type and ratio of organic solvents, and column temperature. The method was validated according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guidelines. There is no report using micellar liquid chromatography to detect isoflavones, and the optimized method has been successfully applied to quantify isoflavones in red clover and Radix Puerariae. This method is efficient, cheap, and convenient. Finally, we verified the existence of supramolecular amphiphilic vesicles in the mobile phase by transmission electron microscopy to explain the increased chromatographic efficiency.

Effect of Methyl Ethyl Ketone (MEK) Organic Solvent Exposure on Incidence of Neurotoxicity in Shoe Manufacturing Workers

Background: Shoe manufacturing factory workers in developing countries are daily exposed to complex mixtures of organic solvents. Chemical exposure occurs through inhalation / respiration and skin which can affect many physiological systems. The main chemical exposure to organic solvents in shoe manufacturing comes from the process of gluing and cleaning process by using organic solvents on footwear in the assembling section. Methyl ethyl ketone is one type of organic solvent which, when entering into the body through inhalation routes can cause irritation of the nose, throat, lungs and chest becomes congested. Acute neurotoxicity is a collection of symptoms in the central nervous system (central nervous system depression, psychomotor disorders, narcosis, drowsiness, headache, dizziness, dyspepsia, and nausea).&#x0D; Method: The research design was a prospective cohort research consisting of 45 people for each high MEK exposed group and low exposed to MEK. Data collection was done by interview, physical examination, MEK level measurement of pre-shift urine and end-shift work, and filling out questionnaires Form Acute symptoms rating questionnaire at the beginning of work shift (07.00), 2 hours after work (09.00), break (12.00), 2 hours after break (15.00), and end of work shift (16.00).&#x0D; Result: The incidence of acute neurotoxicity symptoms in the MEK-high exposed group based on the Acute Symptoms questionnaire was 51.1%. Age factor with symptoms of acute neurotoxicity in workers at PT. X with p value = 0.432, gender factor with p value = 0.162, education factor with p value = 0.897, nutritional status factor with p value = 0.865, alcohol habit factor with p value = 0.181, coffee drinking habit factor with p value = 0.265, and smoking habit factor with p value = 0.968, work duration factor with symptoms of acute neurotoxicity at worker in PT. X with p value = 0.533, and the use factor of personal protective equipment (PPE) with p value = 0.470. In this research, symptoms of acute neurotoxicity were dominant are fatigue (80%), headache (77.8%), nausea (71.1%), dizziness (66.7%), and feeling of intoxication (53.3%).&#x0D; Conclusion: There are no subject and occupational factors that have a significant effect to the symptoms of acute neurotoxicity. Conducting isolation of other work areas for workers exposed to chemicals that because of high potential to harm other workers in the vicinity. Reassessing the hazard risk of using MEK substitutes with other chemicals that are of lower risk or replace with water-based solvents. Provide PPE eligible to all workers exposed to chemicals and workers around them. A PPE fit test is used for workers to feel comfortable while wearing it, giving strict sanctions to workers who do not consistently use personal protective equipment.

Preconcentration and Determination of Clomiphene Citrate Using Hollow- Fiber Liquid-phase Mixroextraction Coupled with HPLC-UV Detection

Background: Currently, ovulation stimulation with clomiphene citrate is the most commonly used treatment in infertility. It stimulates the secretion of gonadotropins necessary for the release of an egg. Objective: In this study, a microextraction method of liquid phase was utilized using hollow fiber with high-performance liquid chromatography and ultraviolet (HPLC-UV) detector for pre-concentration and measuring clomiphene citrate in plasma. Method: Clomiphene citrate was extracted from a 15 ml sample solution with pH=11 in an organic solvent (Octanol), which was located in the vent wall of the fiber. Subsequently, the drug was introduced into an internal organic solvent into an acidic pH=2 receptor that was located inside the fiber. In the following, effective factors in microextraction including pH of the donor phases and acceptor phases, type of organic solvent, ion phase strength, extraction time and stirring speed were investigated and optimized. Results: After extracting the drug with an optimal pre-concentration factor of 212, extraction recovery was 91%, the detection limit was 1.50 ng/ml, limiting the linearity of 5-1000 ng/mL and %RSD=6.98. Conclusion: The proposed method was successfully implemented and optimized for trace detection of clomiphene citrate in plasma, therefore the clinical and investigational application of this method is facilitated by this study.

Analysis of Superhydrophobic-Superoleophilic Properties on Modification of Polyurethane Sponge for Selective Oil-Water Separation

In this research, a modification of polyurethane (PU) sponge material has been made to obtain superhydrophobic-superoleophilic properties. The PU sponge was coated with several nanomaterials such as ZnO, Fe3O4+TEOS, and stearic acid by dip-coating and drop-coating methods. The tests include selective separation of oil and water with a magnetic response. Several types of oil and organic solvents were tested for absorption capacity. The results showed that the PU@ZnO@Fe3O4@SA sponge has a good absorption capacity, from 4.37 mL to 7.37 mL. The fabricated PU sponge could selectively separate oil from water with a separation efficiency above 99%. The fabricated PU sponge also could be magnetically driven by external magnetic fields. From the characterization using 3D OM, the water contact angle was 153.38°, which indicates that the PU@ZnO@Fe3O4@SA sponge is superhydrophobic. And from surface morphology obtained an average pore size diameter of 167.475 μm.

Effect of the addition of deep eutectic solvent to the anthracene separation

Anthracene (AN) is an important fine chemical feedstock, mainly derived from the anthracene oil fraction of high-temperature coal tar. The traditional solvent crystallization method used to obtain anthracene involves large amounts of solvents. A method with a high separation capacity and a high selectivity needs to be developed urgently. To this end, the composition of crude AN oil and the solubility of its main components in xylene were determined, and phenanthrene in crude AN oil was extracted with xylene. Pure deep eutectic solvents (DESs) and DESs–organic solvent mixture were then applied to separate anthracene and carbazole, respectively. Based on the distribution coefficient, selectivity, and purity of the AN product, the influence of organic solvent type, the molar ratio of DESs to organic solvent, and DESs type on the separation efficiency were investigated. Finally, the separation mechanism was investigated with density functional theory calculations and UV–visible spectroscopy. The results show that the phenanthrene content decreased from 25.5% to 2.6% and most of other condensed aromatics in crude AN were removed after washing twice with xylene. DESs–organic solvent mixtures had better performance than pure DESs for the separation of anthracene and carbazole, and under optimal condition, the 97.5% purity of AN is acquired in a single separation step with a tetraethyl ammonium chloride–glycerol DESs–DMF mixture. The more complicated interactions between phenanthrene and xylene than between anthracene / carbazole and xylene favored the removal of phenanthrene. The hydrogen bond with the minimum bond energy (-17.6 kJ/mol) between DESs and carbazole is also stronger than that with the maximum bond energy (-16.8 kJ/mol) between DESs and anthracene. Adding DESs to organic solvent can enhance the interactions between carbazole and the solvent, but had no significantly influence on interactions between anthracene and the solvent, thereby facilitating the separation of anthracene and carbazole.