Ml Of Toluene Research Articles

Surface-Pore-Modified N-Doped Amorphous Carbon Nanospheres Tailored with Toluene as Anode Materials for Lithium-Ion Batteries.

The surface modification of amorphous carbon nanospheres (ACNs) through templates has attracted great attention due to its great success in improving the electrochemical properties of lithium storage materials. Herein, a safe methodology with toluene as a soft template is employed to tailor the nanostructure, resulting in ACNs with tunable surface pores. Extensive characterizations through transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption isotherms elucidate the impact of surface pore modifications on the external structure, morphology, and surface area. Electrochemical assessments reveal the enhanced performance of the surface-pore-modified carbon nanospheres, particularly ACNs-100 synthesized with the addition of 100 μL toluene, in terms of the initial discharge capacity, rate performance, and cycling stability. The interesting phenomenon of persistent capacity increase is ascribed to lithium ion movement within the graphite-like interlayer, resulting in ACNs-100 experiencing a capacity upswing from an initial 320 mAh g-1 to a zenith of 655 mAh g-1 over a thousand cycles at a rate of 2 C. The findings in this study highlight the pivotal role of tailored nanostructure engineering in optimizing energy storage materials.

Process intensification of microwave-assisted acetylation reaction of glycerol to synthesize fuel additives using porcine pancreas lipase catalyst

To reduce the level of greenhouse emissions, new technical advancements in the fields of biofuels, wind, and solar energy are being made. The most widely used biofuel is biodiesel. Glycerol production has grown as a result of increased biodiesel production. Glycerol may be processed to create valuable chemicals. In this research, a glycerol acetylation reaction with acetic acid was carried out to synthesize glycerol acetate using an enzyme lipase catalyst extracted from porcine pancreas (PPL). Experiments were carried out to analyze the effect of various solvents (toluene, n-butyl alcohol, tert-butyl alcohol, dichloromethane, isopropyl alcohol), power level (900 and 1200 W), and temperature (20–50 °C) on glycerol conversion. Ninety-six percent of glycerol conversion was achieved for a duration of 2 h with the use of 10 mL of toluene as solvent. The kinetics of the acetylation reaction catalyzed by PPL in a microwave reactor was also studied using an elementary kinetic law. Applying process intensification using a microwave reactor was found to be advantageous. The microwave effect in accelerating the rate of acetylation reaction at reduced temperature compared to the conventional method was observed in this study. The activation energy (E) for the acetylation reaction was found to be 18 kJ/mol.

Synthesis of Ag-Cu-Ni Nanoparticles Stabilized on Functionalized g-C3N4 and Investigation of Its Catalytic Activity in the A3-Coupling Reaction.

In the present research, using ethylenediamine and hydrazine hydrate as the capping and reducing agents in this investigation, respectively, Ag-Cu-Ni NPs were immobilized on the functionalized g-C3N4 surface. This nanocatalyst was studied in terms of its catalytic activities for the A3-coupling reaction to synthesize propargylamine derivatives. According to the results, in the presence of 1 mL of toluene as the solvent and 20 mg of the g-C3N4-TCT-2AEDSEA-Ag-Cu-Ni nanocatalyst, the maximum efficiency of the nanocatalyst occurred at a temperature of 80 °C. Products were purified using thin-layer chromatography plates (silica gel) by employing n-hexane/ethyl acetate with a 90:10 ratio. In addition, the prominent benefits of the synthesized nanocatalyst include its high yields of the product, cost-effectiveness, recyclability, and easy separation. The novelty of the catalyst is due to the presence of Ag-Cu-Ni nanoparticles at the same time in the structure of the functionalized g-C3N4 substrate. So, Ag-Cu-Ni can be strongly connected to the substrate. The structure of the synthesized nanocatalyst was characterized using Fourier transformed infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating-sample magnetometry, and transmission electron microscopy.

Effect of molecular weight distribution on the thermal adhesion of polystyrene and PMMA brushes

The effect of the molecular weight distribution (MWD) and graft density of polymer brushes on the adhesion strength of flat substrates was investigated using polystyrene (PS) and poly(methyl methacrylate) (PMMA) brushes with variations in the molecular weight, MWD, and graft density. Two silicon wafers covered with polymer brushes were bound in a 0.5 cm2 contact area using 5 μL of toluene and a pinchcock Hoffman clamp and then annealed at 408 K in a vacuum oven for 3 h. PS brushes with a MWD narrower than Mw/Mn = 1.20 yielded an adhesion strength lower than 0.1 MPa. In contrast, PS brushes having a broad MWD (Mw/Mn = 1.3–1.4) were successfully joined to afford a lap shear adhesion strength of 1.2 MPa despite high graft density due to the intermixing of longer chains of the opposite brushes. Similar results were also obtained in the case of PMMA brush.

Validation of gas chromatography mass spectrometry (GC-MS) qualitative method for detection of paraquat in postmortem samples by sodium borohydride-platinum chloride chemical reduction

To develop a GC-MS method for the detection of paraquat by sodium borohydride-platinum chloride reduction in postmortem samples. Paraquat [1,1′-dimethyl-4,4′-bipyridilium dichloride,(PQ)] is a bipyridylium quaternary ammonium contact herbicide. At the Institute of Forensic Science and Legal Medicine (IFSLM), an average of 13 cases of PQ poisoning are submitted annually for postmortem toxicological analysis. Previously a colorimetric method for the identification of PQ was used. A more sensitive method was needed to confirm the presence of PQ. There is limited studies on liquid-liquid extraction (LLE) of postmortem fluids and tissues for determination of PQ by GC-MS. Some methods used a chemical reduction involving sodium borohydride (NaBH4) or sodium borohydride with nickel chloride (NaBH4-NiCl2), prior to LLE, to gain more volatile compounds for analysis. In the absence of NiCl2, platinum (IV) chloride (PtCl4) was used as a substitute catalyst in the validation. The aim of this validation is to identify PQ in suspected poisoning cases from postmortem samples using chemical reduction reaction, followed by LLE and then (GC-MS). The qualitative method involved an initial chemical reduction of PQ to the perhydrogenated product and monoene by-product: 500 μL blood, urine or tissue homogenate was placed in a glass tube, followed by 200 μL toluene, 400 μL PtCl4 (1% w/v) and then 500 μL NaBH4 (40% w/v) was added dropwise. The mixture was vortexed then left to stand for 1½ hours at room temperature. 1 mL 5 N sodium hydroxide solution was added to stop the reaction. For LLE, 3 mL hexane: ethyl acetate (4:1) was added to the tube and placed on shaker for 45 minutes at 300 rpm. The sample was centrifuged for 1 hour at 1400 g. The hexane:ethyl acetate layer was then transferred to a beaker and allowed to evaporate to dryness. The residue was reconstituted with 1 mL hexane, transferred to GC vial, and allowed to evaporate to dryness. The residue was then reconstituted with 100 μL hexane, and transferred to a GC vial fitted with glass insert, with 1 μL being injected into the GC-MS system (Agilent 7890A GC coupled with an Agilent 5975C VL MSD with Triple Axis Detector Mass Spectrometer). As recommended by the Scientific Working Group for Forensic Toxicology (SWGTOX), the validation parameters for qualitative confirmation/identification were specificity, recovery, carryover, repeatability and limit of detection. The method was applied to blank blood and urine samples, spiked blood and urine samples, as well as 10 suspected PQ poisoning cases (24 postmortem samples) submitted to the IFSLM. The blank blood and urine samples analysed did not yield any positive results for the analytes of interest. Blood and urine samples spiked with the PQ standard solution resulted in the detection of both the perhydrogenated product and monoene by-product. The limit of detection for both reduction products was 30 ppm. There was no detection of the analytes in the three blanks analysed after an injection of 1000 ppm PQ. The reduction products of PQ were detected in all 10 cases. Four of these cases had previously given negative results using the colorimetric test. The PtCl4 was found to be an adequate substitute catalyst in the reduction procedure. The procedure was proven to be sensitive, repeatable and robust. All sample types assessed by the method gave positive results, however stomach and content produced the best chromatograms with sharp, clearly defined and resolved peaks. In summary, the presented procedure provided excellent performance in the identification of the reduction products of PQ in postmortem samples.

Emulsion breaking-induced extraction of Cd and Pb from oily dietary supplements followed by graphite furnace atomic absorption spectrometry detection

A method is described for the determination of cadmium (Cd) and lead (Pb) in oily dietary supplements using extraction induced by emulsion breaking (EIEB) and high-resolution continuum-source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). The method is based on the formation of a water-in-oil emulsion by the addition of an extractor solution consisting of 5 % (w/v) Triton X-100% and 15 % (v/v) hydrochloric acid (HCl) to the sample of oil diluted with 1.5 mL of toluene and the breakage of this emulsion by centrifugation (4000 rpm for 5 min). Two well-defined phases were formed and the acid aqueous phase containing extracted Cd and Pb ions was analyzed by HR-CS GFAAS. Different parameters that influence the extraction efficiency of Cd and Pb were optimized univariately. The detection limits were 3.32 μg kg−1 for Pb and 1.51 μg kg−1 for Cd. A matrix-based calibration method was applied to compensate for the interference caused by the matrix effects. The Cd concentration in the samples ranged from 8.81 to 9.35 μg kg−1 and the highest concentration of Pb was 19.91 μg kg−1. The proposed preparation of sample through extraction by breaking emulsions of oily dietary supplements proved to be a simple and efficient strategy to determine the amount of Pb and Cd by HR-CS GFAAS.

Monometallic and heterobimetallic ruthenium (II) and palladium (II) complexes based on a pyridine‐hydrazone ligand as bifunctional catalysts for ROMP of norbornene and ethylene polymerization

AbstractThe monometallic complex [Pd(L)(PPh3)] (mono‐Pd) was synthesized using a potentially tridentate hydrazone (H2L) and used as precursor to prepare a heterobimetallic ruthenium (II)‐palladium (II) complex [Cl2(p‐cymene)Ru(μ‐L)Pd (PPh3)] (Ru‐Pd). Mono‐Pd and Ru‐Pd were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet‐visible spectroscopy (UV–Vis), 1H, 13C{1H} and 31P{1H} nuclear magnetic ressonance(NMR) spectroscopy, elemental analysis, cyclic voltammetry, matrix‐assisted laser desorption/ionization ‐ time of flight (MALDI‐TOF) mass spectrometry, and computational methods. The mono‐Pd was additionally studied by single‐crystal X‐ray diffraction. The complex [RuCl2(p‐cymene)(Isoniazid)] (mono‐Ru) was also obtained following literature methods aiming a comparison in the catalytic activity. The ring opening metathesis polymerization (ROMP) of norbornene (NBE) using mono‐Ru or Ru‐Pd as precatalysts in the presence of ethyl diazoacetate (EDA) was evaluated as a function of time (10–60 min) using [NBE]/[EDA]/[Ru] = 5000/28/1 at 50°C. The time increases produced good yields of polyNBE, reaching 38% and 46% for mono‐Ru and Ru‐Pd, respectively. The polyNBE produced was measured by size‐exclusion chromatography (SEC) and reached an order of magnitude of 105 g·mol−1 of Mn, with Ð values ranging from 2.51 to 1.86 for mono‐Ru and from 3.50 to 1.66 for Ru‐Pd. The catalytic activity of mono‐Pd and Ru‐Pd on ethylene polymerization was assessed with a range of [Al]/[Pd] molar ratio between 350 and 1750, 30–70°C temperature, 2 to 4 h reaction time, and total reaction volume of 25 and 50 ml. Mono‐Pd achieved an activity of 22.80 kg PE (mol Pd)−1 h−1 at 60°C after 4 h using [Al]/[Pd] = 1050, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. For Ru‐Pd, an activity of 20.35 kg PE (mol Pd)−1 h−1 at 60°C after 4 h was obtained using [Al]/[Pd] = 1750, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. Overall, Ru‐Pd showed to be active in both ROMP and ethylene polymerization reactions, being categorized as a bifunctional catalyst.

Gold Nanoparticle Synthesis.

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

Extraction and preconcentration of Bisphenol A and 4-Nonylphenol in aqueous solutions using microfunnel supported liquid-phase microextraction prior to high performance liquid chromatography

In this study, liquid-phase microextraction using low-density extraction solvents with microfunnel was applied for the extraction and preconcentration of Bisphenol A and 4-Nonylphenol in aqueous samples. The goal of the present method is to develop a special device that allows organic solvent remain on the surface of aqueous phase as a thin layer during the extraction time. At the end of extraction period, organic phase containing the extracted analytes was collected easily and analyzed by HPLC–FLD. Toluene used as extraction solvent and some of experimental parameters were optimized by L16 Taguchi experimental design. According to the results, the volume of extraction solvent as well as ionic strength showed significant effect on the extraction recovery. Under the optimum conditions (sample volume: 320 mL; pH 8.0; ionic strength: 10% (w/v) NaCl, extraction time: 90 min and extractant: 600 μL toluene), limit of detection, limit of quantification and dynamic linear range of the proposed method for Bisphenol A were calculated as 0.05, 0.2 and 0.2–62.5 μg L−1, and for Nonylphenol were obtained as 3.1, 6.2 and 6.2–125 μg L−1, respectively.

The rheological properties of asphalt modified by commercial adhesive (Ethylene-vinyl acetate) and air blowing process

In this study, we modify the rheolgical prioperties of asphaltic materials by addative and air blowing. For this process, asphaltic materials have been oxidized by air blowing in the presence of anhydrous aluminum chloride as a catalyst for this process . Air blowing was conducted in different condtions of temperature and times using 0.5%(by weight) from catalyst, after determining the optimal conditions for air blowing, we changged the percentage of catalyst to get the optimal perecentage which can be using in modified process, then the asphalt was treated with the commercial adhesive (EVA) in two phaths: The first path was included addtion of different percentages from commercial adhesive under the optimal condition from air blowing and perecentage of alaminum chloride. The second path was included dissolved the commercial adhesive in the toluene and then the modified process was conducted at same conditions in the first path, ( toluene was added to the commercial adhesive by ratio (1:6) (weight of commercial adhesive: ml of toluene). The results showe rheological properties that are compeletly differentj from the original asphaltic materials . The study was gave modified asphaltic materials that can be using in different fields, some samples can be using in paving as in samples (AS19, AS24, AS25) and other as mastic or as flattening as in samples (AS15, AS16, AS17, AS21, AS22). The usage of asphalitic materials in various fields depends on the measurments of different properties such as (ductility, penetration, softining point ,asphaltens percentage, penetration index ,aging test, marshall test).

Enhanced adsorption/extraction of five typical polycyclic aromatic hydrocarbons from meat samples using magnetic effervescent tablets composed of dicationic ionic liquids and NiFe2O4 nanoparticles

Owing to matrix complexity, the development of green and convenient pretreatment methods is crucial for routine monitoring of organic contaminants in meat samples. Dicationic ionic liquids (DILs) possess two active centers, thus resulting in superior physicochemical properties over monocationic species. Herein, the hydrophilic DILs and in-situ metathesis reaction salt were introduced into NiFe2O4-based magnetic effervescent tablets for enhancing adsorption/extraction of five typical polycyclic aromatic hydrocarbons (PAHs) in meats. Also, the synthesized NiFe2O4 nanoparticles displayed larger specific surface area than others (CoFe2O4, Fe3O4 and ZnFe2O4), thereby supplying higher adsorption capacity for PAHs. The integration of DILs with NiFe2O4 into magnetic effervescent tablets realized highly efficient adsorption/extraction, rapid magnetic separation/retrieval and CO2-induced vigorous dispersion into one synchronous step. After hydrolysis of the ground meat samples using 10 μM KOH, the filtered solution was diluted and subjected to magnetic effervescent tablet-assisted microextraction procedures. Optimized experimental variables were as follows: an effervescent tablet containing 0.7 g Na2CO3 and NaH2PO4 with molar ratio of 1:2; 60 mg [C4(MIM)2]Br2; 20 mg NiFe2O4; 45 mg Na[N(CN)2] and 500 μL toluene as elution solvent. The effervescent reaction-enhanced microextraction was combined with high performance liquid chromatography and fluorescence detection, rendering limits of detection as low as 0.01–0.07 μg kg−1 with high recoveries (82.3–104.7%) for five PAHs in raw, boiled, charcoal-grilled and smoked meats. To the best of our knowledge, this is the first report on the additive action between DILs and NiFe2O4 in an effervescent reaction-enhanced microextraction, showing great analytical potential in meat matrices.

Extraction induced by emulsion breaking for simultaneous determination of Co, Fe and Ni in petroleum asphalt cement by high-resolution continuum source atomic absorption spectrometry

This paper reports, for the first time, the simultaneous determination of Co, Fe and Ni in petroleum asphalt cement by high-resolution continuum source atomic absorption spectrometry after extraction induced by the emulsion breaking method. The variables that could influence the sample preparation were evaluated, like sample dilution with toluene and mineral oil, extraction time, HNO3 and Triton X-100 concentration in the aqueous extractant solution. At optimized conditions, 0.08 g of the sample was dissolved with 1.5 mL of toluene and 3.5 mL of mineral oil and vigorous mixed with the extractant solution containing 40% (v/v) of HNO3 and 40% (v/v) of Triton-X-100. The emulsions were broken by heating just after their formation and the aqueous extracts were collected for analysis. Simultaneous determination was carried out at the secondary lines of Co (352.685 nm), Fe (352.604 nm) and Ni (352.454 nm). For this purpose, the best pyrolysis and atomization temperatures were 700 and 2400 °C, respectively. Calibration was performed with standard aqueous solutions and no matrix effects were observed. The limit of detection was 0.003 mg L−1 for Co, 0.018 mg L−1 for Fe and 0.027 mg L−1 for Ni. Method accuracy was confirmed by comparing the results obtained by the proposed extraction method with those obtained after samples acid digestion. Recoveries ranged from 100 to 107%, 103 to 109% and 95.5 to 98.9% were obtained for Co, Fe and Ni, respectively.

Dispersive micro-solid phase extraction using cotton based carbon fiber sorbent for the determination of three polycyclic aromatic hydrocarbons in tea infusion by gas chromatography-quadrupole mass spectrometry

In this study, carbon fibers (CFs) were used as sorbent material for the dispersive micro-solid phase extraction (d-μSPE) of anthracene, acenaphthene and phenanthrene from tea infusion samples prior to gas chromatography-quadrupole mass spectrometric detection. CFs were obtained by carbonizing cotton at 800 °C under the protection of nitrogen for 4 h. After characterization by the scanning electron microscopy-energy dispersive spectrometry, X-ray diffraction and N2 adsorption-desorption, 20 mg of CFs were used to effectively adsorb PAHs in 5 min from 10 mL of tea infusion samples, 2 mL of toluene was used as desorbent. Under the optimum conditions, good linearity was obtained with R2 between 0.9996 and 0.9998. The limits of detection were in the range of 0.012–0.014 μg/L. RSD values for intra- and inter-day precision were ≤6.7% and ≤7.8%, respectively. In this work, cotton based CFs were prepared in a solventless and green way and the CFs based d-μSPE procedure was simple, rapid and cost-effective, with no need of column-packing. The proposed method has been successfully applied to the analysis of PAHs in three kinds of tea infusion samples.

Natural emulsion gels and lecithin-based sorbents: A potential treatment method for organic spills on surface waters

Natural sorbents for the removal of a free toluene phase from water were made using lecithin, food-grade oils (canola, sunflower, safflower and corn oil) and water, or lecithin, hydroxystearic acid (HSA) and canola oil, or lecithin, HSA and soy wax. Lecithin (5 g), food-grade oils (5 mL), and water (5 mL) formed emulsions, in which clusters of water droplets were dispersed in oil, as probed using confocal microscopy and cryo-scanning electron microscopy (cryo-SEM). These emulsions were gel-like, with shear elastic moduli (G’) greater than the shear viscous moduli (G”). Emulsion gels obtained with lecithin, canola oil and water could absorb up to 47% (volume based) of toluene freely floating on deionised water in 20 h. G’ increased from 1621 ± 203 Pa to 6372 ± 168 Pa upon mixing with up to 20% of toluene (volume based), and decreased to 2130 ± 376 Pa and to 846 ± 60 Pa with 33% and 47% toluene (volume based), respectively. However, the gels remained cohesive enough to be recovered from water even with 47% toluene, facilitating it removal. The gels lost instead cohesiveness with 67% of toluene. Similar trends were observed with all other food-grade oils used and in the presence of CaCl2 salt. With 35 g/L NaCl and 33% toluene gels less cohesive than with DI or CaCl2 salt. Optical microscopy showed that lecithin formed thick, heterogeneous films at the oil-water interface in the absence of toluene. Toluene addition to lecithin in canola decreased the interfacial tension (as probed with the pendant drop method), rendered the lecithin interfacial films homogeneous and improved the miscibility between the oil and the water phase, as observed through confocal microscopy. Toluene addition also affected the lamellar swelling of lecithin bilayers, which were studied using Wide and Small Angle X-ray Scattering (WAXS and SAXS). Addition of HSA or HSA and soy wax to the emulsion gels increased their shear viscoelastic moduli before and after mixing with toluene. Gels comprised of HSA (0.5 g), lecithin (4.5 g), canola oil (2.5 mL) and water (5 mL) or of HSA (0.5 g), lecithin (3 g), soy wax (1.5 g) and water (5 mL) could absorb approximately 10 mL of toluene (i.e. 67% of the lecithin gel volume) in 20 h. Addition of HSA also increased the cohesiveness of gels with toluene and 35 g/L NaCl.

Detection of C60 in environmental water using dispersive liquid–liquid micro-extraction followed by high-performance liquid chromatography

ABSTRACTThe wide application of fullerene C60 nanoparticles would inevitably lead to their release into the environment. In order to evaluate the environment risks of C60 and the subsequent effects on ecosystem health, a reliable quantitative methodology of C60 should be established. In this study, a rapid pretreatment method called low-density solvent-based dispersive liquid–liquid micro-extraction (DLLME) combined high-performance liquid chromatography-UV detector (HPLC-UV) was developed to detect C60 in environmental water. In this proposed method, toluene and methanol were chosen as the extraction solvent and the dispersive solvent, respectively. The optimized volume of extraction solvent and dispersive solvent were 100 μL and 10 μL, respectively. And the best shaking time was chosen as 10 min at room temperature for the optimal homogenization procedure for the extraction of C60 in water samples. The enrichment factor of 50 was obtained with 100 μL toluene, and the recoveries of C60 from various environmental samples were in the range of 81.4 ± 5.0–101.4 ± 6.2% at 1.25–5.00 µg/L spiked levels. The detection limits of C60 in tap water, surface water, living sewage and mining waste water were 0.19, 0.29, 0.34 and 0.22 μg/L, respectively. The low detection limit, good linear range and high recoveries of C60 in environmental water indicated that the proposed method could provide an efficient approach for the analysis and tracking of C60 in the environment.

Synthesis of copper(II) ion‐imprinted polymers via suspension polymerization

Copper(II) (Cu2+) ion‐imprinted polymers were prepared by suspension polymerization using 2.5 mmol of copper(II) sulfate pentahydrate as the template ion, 5 mmol of 4‐vinylpyridine and methacrylic acid as functional monomers, 20 mmol of ethylene glycol dimethacrylate as the cross‐linker, 1 mmol of 1,1′‐azobis(cyclohexanecarbonitrile) as the initiator in the porogen of 10 mL of toluene, and hydroxypropyl methyl cellulose as a stabilizer in the polymerization reaction. The obtained polymers were used to quantify Cu2+ ion by using flame atomic absorption spectroscopy. Chemical structure, morphology, crystalline structure, and surface area of polymers were investigated by Fourier transform infrared spectroscopy, scanning electron microscope, X‐ray diffraction, and Brunauer‐Emmett‐Teller respectively. The diameters of the synthesized polymer particles were about 250 nm. The Cu2+ ion‐imprinted polymers illustrated good recognition property and selective adsorption ability with Cu2+ higher than Mn2+ and Fe2+. Thus, this work could be applied as a sorbent from the enrichment of Cu2+ ions in analytes.

Sillica Gel-Amine from Geothermal Sludge

Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

Determination of trace amounts of chlorobenzenes in water using membrane-supported headspace single-drop microextraction and gas chromatography–mass spectrometry

A novel method based on the coupling of membrane-supported headspace single-drop microextraction with gas chromatography‒mass spectrometry (GC–MS) is developed for the determination of chlorobenzenes in water samples. For the determination of five chlorobenzenes, a 15 μL toluene microdrop was placed inside the plastic membrane and exposed for 10 min for headspace extraction while stirring at 1000 rpm. The microdrop was then picked up by a microsyringe and directly injected into the injector block of the GC–MS instrument. Under the optimized operation conditions, the calculated calibration curves gave a high level of linearity for all targets with correlation coefficients range from 0.9945 to 0.9987. The limits of detection range from 0.01 to 0.05 μg/L and the RSDs for most of chlorobenzenes were below 7%. The method is simple, sensitive, and stable for single drop microextraction. Its applicability is demonstrated by the determination of chlorobenzenes in tap water samples.

醋酸钴/TBHP催化氧化取代甲苯反应的研究

苯甲酸及其衍生物作为一类重要的有机化工中间体，广泛用于生产医药、香料和食品防腐剂等生产中。本文通过在常压、无溶剂条件下，过氧化叔丁醇(TBHP)和醋酸钴结合催化氧化取代甲苯合成了一系列苯甲酸衍生物，确定了催化取代甲苯氧化合成苯甲酸类衍生物的最优反应条件为：1 mol% Co(OAc)2•4H2O，3当量的TBHP，取代甲苯5 mL，反应温度为100℃，反应时间为24 h。该方法具有选择性高，反应条件温和，催化剂廉价易得，分离简单，底物适用范围广等优点。 Benzoic acid and its derivatives as an important class of organic chemical intermediates, is widely used in the production of pharmaceutical, perfume and food preservatives. In this paper, tert- butyl hydroperoxide (TBHP) and cobalt acetate combined catalytic oxidation of substituted toluene synthesized a series of benzoic acid derivative at atmospheric pressure in the absence of solvent, and identified the catalytic oxidation of toluene substituted to benzoic acid derivatives. The optimal reaction conditions were as follow: 1 mol% Co(OAc)2•4H2O, 3 equivalents of TBHP, 5 mL of toluene, reaction temperature 100˚C, reaction time 24 h. The method has many advantages of high selectivity, mild reaction conditions, cheap and readily available catalyst, simple separation, a wide suitable range of substrates.

Ultrasonication Extraction - HPLC-VIS Fluorescence Method Validation for Trace Analysis of Oil and Grease in Water

A new method was developed to determine the oil and grease in water by HPLC-Vis fluorescence technique. Ultrasonication liquid-liquid extraction method was applied by using 1 ml of toluene to 100 ml of water. The analysis was carried out on a LC-10AT-VP chromatograph with a fluorescence RF. 10 a syknm detector equipped with a varian CN (250 × 4.6 μm) Column. The separation was preformed isocratically using a mixture of 90% solvent (n-Hexane) with 10% solvent (Toluene). Asphaltenic compounds were established to be the main fluorescence chromophores (excitation wave length at 420 nm and emission wave length at 500 nm). The correlation coefficient was (0.992), recovery ranged from 92% to 108% and the limit of detection was found to be 0.06 μg.L-1. The method can be utilized successfully for determination of oil and grease in water samples.