Cethyltrimethylammonium Bromide Research Articles

DNA EXTRACTION FROM LOCAL SOUVENIR OF SUKU ANAK DALAM JAMBI WITHOUT LIQUID NITROGEN USING CTAB METHOD

One of the local souvenirs from Jambi is accessories made from the seed bark of the sebalik sumpah tree. The sebalik sumpah tree is currently quite rare. Through DNA isolation, sebalik sumpah is one of the efforts of genetic conservation and as a first step in cultivating sebalik sumpah trees. DNA isolation is the initial stage in molecular analysis. The purpose of DNA isolation is to obtain genomic DNA from a sample. Plant DNA isolation generally uses fresh plant samples, with young and soft plant parts. This is recommended to obtain good quality genomic DNA. However, with the limitations of fresh samples, a method is needed that is able to extract DNA from plants that have changed shape and have undergone processing. Each plant requires a different method to obtain DNA. The CTAB (Cethyl Trimethyl Ammonium Bromide) buffer method is a method commonly used in plants because it is able to extract DNA with high polysaccharide and phenol content, so many have modified the method. This study aims to determine the success of the CTAB method without nitrogen in extracting processed materials and the length of incubation time at the precipitation stage. Extraction was carried out by liquid nitrogenless CTAB method with the addition of PVP (Polyvinylpolypyrrolidone). The results show that the CTAB method without liquid nitrogen is able to extract plant samples that have undergone processing and the length of incubation time at the precipitation stage affects the DNA produced.

Cationic Surfactant-Modified Tetraselmis sp. for the Removal of Organic Dyes from Aqueous Solution

The modification of the Tetraselmis sp. algae material (Tetra-Alg) with surfactant Cethyltrimethylammonium Bromide (CTAB) yielded adsorbent Tetra-Alg-CTAB as an adsorbent of methyl orange (MO) and methylene blue (MB) solutions. The characterization of the adsorbent used an infrared (IR) spectrometer to identify functional groups and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX FEI Inspect-S50, Midland, ON, Canada) to determine the surface morphology and elemental composition. Methyl orange and methylene blue adsorption on the adsorbent Tetra-Alg, Tetraselmis sp. algae-modified Na+ ions (Tetra-Alg-Na), and Tetra-Alg-CTAB were studied, including variations in pH, contact time, concentration, and reuse of adsorbents. The adsorption of MO and MB by Tetra-Alg-CTAB at pH 10, during a contact time of 90 min, and at a concentration of 250 mg L−1 resulted in MO and MB being absorbed in the amounts of 128.369 and 51.013 mg g−1, respectively. The adsorption kinetics and adsorption isotherms of MO and MB and Tetra-Alg, Tetra-Alg-Na, and Tetra-Alg-CTAB tend to follow pseudo-second-order kinetics models and Freundlich adsorption isotherms with each correlation coefficient value (R2) approaching 1. Due to the modification with the cationic surfactant CTAB, anionic dyes can be strongly sorbed in alkaline pH due to strong electrostatic attraction, while MB is more likely to involve cation exchange and hydrogen bonding. The reuse of Tetra-Alg-CTAB was carried out four times with adsorption percent > 70%, and the adsorbent was very effective in the adsorption of anionic dyes such as MO.

Anoda Pb dan Gel Elektrolit Untuk Propulsi Kapal Selam

Battery is the most important component in the sub marine energy system. Up to now, majority of the sub marine are still using lead acid battery as the power source or propulsion, due to more safe in application as very high capacity of single cell (i.e. 10.000 – 15.000 Ah). The drawbacks of aqueous based battery, which utilize liquid electrolyte, are because of having produced the hydrogen gas during charging process, in which it caused the electrolyte solution to become dry and reduced the performance of battery. In addition that the hydrogen gas generated in the sub marine was dangerous. Therefore, the aim of this research is how to reduce or eliminate of those drawbacks by modifying kind of the liquid electrolyte by using gel electrolyte. The gel electrolyte was synthesized to reduce the evaporation of electrolyte and to avoid the leaking when submarine maneuver. The gel electrolyte  was made by using inorganic nanoporous MCM-41. It was synthesized by hydrothermal method, using Tetraethylortosilicate (TEOS) as silica sources, Cethyltrimethylammonium bromide (CTAB) as organic template and H2SO4 as catalyst. The MCM-41 lead acid battery gave a result of  OCV ca. 2,1 V.

Adsorption of Methylene Blue Dye by Cetyltrimethylammonium Bromide Intercalated Polyaniline-Functionalized Montmorillonite Clay Nanocomposite: Kinetics, Isotherms, and Mechanism Study.

In this study, new adsorbents were prepared by modifying a montmorillonite clay (Mt) with cethyltrimethyl ammonium bromide (CTAB) to form CTAB-Mt, followed by a second modification process with polyaniline (PAni) to form PAni@CTAB-Mt by in situ polymerization of aniline. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), cyclic voltammetry (CV) and the Brunauer-Emmett-Teller (BET) technique were used to characterize the samples. These adsorbents were used in a batch process to remove methylene blue (MB) from aqueous solution. Factors investigated included initial pH of the solution, contact time and temperature. The adsorption data fit the Freundlich isotherm better than the Langmuir and Temkin isotherms. The maximum adsorption capacities (qeq) obtained were 108.82 mg·g-1, 71.20 mg·g-1 and 57.36 mg·g-1 for PAni@CTAB-Mt, CTAB-Mt and Mt, respectively. The enhanced adsorption capability of the hybrid material is due to increase in surface area and pore volume of the PAni@CTAB-Mt adsorbent. The adsorption results were found to fit well with the pseudo-second-order kinetics model, with highest correlation coefficient (R2) values of 0.954, 0.942 and 0.958 for Mt, CTAB-Mt and PAni@CTAB-Mt adsorbents, respectively. The pH and temperature had a significant effect on the adsorption process, and the negative values of ΔG suggest that the adsorption process was spontaneous and feasible. The desorption and reusability experiment indicated that PAni@CTAB-Mt has the potential to be a reusable adsorbent for MB removal.

Structure and genetic diversity of two populations of Garcinia kola Heckel (Clusiaceae) revealed by RAPD markers

This study aims to characterize the genetic diversity of two populations of Garcinia kola using five RAPD markers in order to contribute to the development of sustainable management and conservation strategy for this species. Genomic Deoxyribonucleic acid (DNA) extracted from leaf fragments of 94 trees from two agroecological (south and west) zones according to Cethyl Trimethyl Ammonium Bromide (CTAB) protocol was analyzed. The mean number of alleles was ranged from 14.2 to 21.2 and the effective number of alleles ranged from 8.62 to 9.44. The average Shannon diversity index was ranged from 2.08 to 2.59 and the average genetic diversity was estimated to be 0.80. A total of 58 polymorphic bands were identified with a polymorphism rate of 100%. According to analysis of molecular variance the most important component of the genetic variation was obtained within population (94%). The analysis of the genetic diversity of all the trees revealed the existence of two groups composed of the trees from the two populations. In addition, genetic differentiation between the two populations was relatively moderate (Fst = 0.061). Sustainable management of G. kola trees should be achieved through in situ conservation. But for ex situ conservation it would be more practical to take as many individuals as possible within populations.

Fabrication of Chitosan-coated Mesoporous Silica Nanoparticles Bearing Rosuvastatin as a Drug Delivery System.

In this work, to improve the solubility and bioavailability of the rosuvastatin (RSV) drug, chitosan-coated mesoporous silica nanoparticles (CS-MSNs) as a drug delivery system were fabricated. To do this, first MSNs with a maximum specific surface area were synthesized from sodium silicate as silica source and different molar ratios of cethyl trimethylammonium bromide (CTAB) and pluronics (P123, PEO20PPO17PEO20) as surfactants via the sol-gel process. Then, the synthesized MSNs were coated by CS polymer with the help of (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) as a linker between MSNs and CS. Subsequently, the RSV drug was loaded into the synthesized CS-coated MSNs. The products were characterized by different techniques, including X-ray diffraction (XRD), the Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The in vitro drug release profile of the fabricated DDS was evaluated in a typical phosphate-buffered saline (PBS) solution at different pH values (i.e., 4, 6, and 7.4) for 48 h. To assess the cytotoxicity, the viability of the human fibroblast cells exposed to the fabricated DDS was also examined. The results showed that at an optimal molar ratio of P123/CTAB, the amorphous MSNs with a specific surface area of about 1080 m2/g, a pore diameter of 4 nm, a pore volume of 1.1 cm3/g, and an average size of about 30 nm were synthesized. Also, the presence of all the components, including the CS coating and the RSV drug, was confirmed in the structure of the fabricated DDS by FTIR analysis. Due to the pH-responsive feature of the CS coating, the RSV drug release from the fabricated DDS showed a reasonable environmental response; as the pH value of the PBS solution decreased, the degree of drug release increased. The CS coating enhanced the cytotoxicity of the fabricated DDS and led to sustainable drug release behavior, which would provide a beneficial approach for drug delivery technology.

Preparation of Pickering‐polyHIPEs from surface modified pumice stabilized high internal phase emulsions as supporting materials for lauric acid impregnation

AbstractPreparation of Pickering‐high internal phase emulsions (HIPEs) of methyl methacrylate (MMA) and divinylbenzene (DVB) by using natural abundant pumice zeolite was performed. Pumice was surface modified with cethyl trimethyl ammonium bromide (CTAB) to increase its compatibility with the emulsion phases. By using a combination of CTAB‐modified pumice (CtP) and low amount of non‐ionic emulsifier mixture Pickering‐HIPEs were obtained. The influence of the amount of surface modified pumice and emulsifier mixture on the emulsion stability was observed. The morphological, thermal, and mechanical properties of the obtained polyMMA‐based Pickering‐polyHIPEs were investigated by altering the amount of CtP loading. Moreover, the Pickering‐polyHIPE monolith exhibiting an open‐porous network was used as supporting matrix for lauric acid (LA). The thermal characterization of the resulting LA impregnated Pickering‐polyHIPE composite revealed that the impregnation rate of LA is 42.08%. The latter formed Pickering‐polyHIPE composite showed a good performance in latent heat storage due to the 111.2 J/g of normalized enthalpy of LA within the Pickering‐polyHIPE composite.

Optimized method for RNA extraction from leaves of forest tree species

Extraction of ribonucleic acid (RNA) from woody plants is a difficult task due to the peculiarities of plant material rich in polysaccharides and starch. The available techniques are often ineffective, since they result in the absence/reduced quality/reduced amount of RNA in the final preparation. The method we have optimized is based on the use of cethyltrimethyl ammonium bromide (CTAB), purification by phenol-chloroform extraction, use of lithium chloride and ammonium acetate. The method showed high efficiency for the extraction of RNA from the leaves of birch and poplar samples, in vitro and mature plants, in comparison with previously used methods (extraction using NucleoSpin® RNA Plant (Macherey-Nagel, Germany) columns, Su (2009) method, standard guanidine thiocyanate method). Electropherograms of RNA preparations showed its high integrity and concentration (up to 85 ng/μl), significantly higher purity of the preparation (up to 2.7 times). Purification of the preparation in the process of extraction can significantly reduce the yield of desoxyribonucleic acid (DNA). The optimized method is highly reproducible and can be used for further research, complementary DNA (cDNA) synthesis, qualitative and quantitative PCR analysis. The method allows obtaining high-quality RNA from other objects of agricultural and forest plants.

Preparation of a New Micro-mesoporous Omega Zeolite by Hydrothermal Route: Effect of Crystallization Time

This work concerns the preparation of a new micro-mesoporous omega zeolite by hydrothermal route. This method consists of the self-assembly of the omega zeolite precursors with a cethyltrimethyl-ammonium bromide surfactant. Different stages of crystallization were studied in order to determine their impact on the textural and structural properties of the resulting materials. For this, several characterization methods were used such as X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, and Energy-Dispersive X-ray. The results showed that the processing time significantly influences on the crystallinity, porosity and Si/Al ratio of the resulting materials. A specific surface area almost three times greater than the parent zeolite was obtained when using non-hydrothermally treated zeolite precursors. While the precursors prepared hydrothermally for 48 or 72 h essentially lead to the formation of the microporous phase corresponding to the Omega zeolite. These new properties can open new applications of these solids notably in the catalysis for the conversion of bulky molecules and also in the adsorption of organic and inorganic pollutants.

Application of Doyle and Doyle method for DNA isolation from pamelo yellow orange (Citrus maxima Merr), lime orange (C. limon) and sunkist orange (C. sinensis)

Various species of the genus Citrus have grown naturally and were cultivated in Indonesia as a mega-biodiversity country. In recent years, the nutritional content and antioxidant activity of citrus fruits has been used to prevent of the various chronic and degenerative human diseases including potential as an antidote to viruses. Development of the potential and superiority of Indonesian oranges including Pomelo yellow orange (Citrus maxima Merr), lime orange (C. limon) and Sunkist orange (C. sinensis) are needed to be done with molecular characterization that begins with DNA isolation. The study was conducted with the aim of applying the Doyle and Doyle method for DNA isolation to all of the three types of oranges. The method for isolate DNA from plant usually use Cethyl Trimethyl Ammonium Bromide (CTAB) and Sodium Dodecyl Sulphate (SDS). The aim of this study is to isolate DNA from the orange leaves of Pomelo Yellow Orange, Lime Orange and Sunkist Orange with the Doyle & Doyle method. The results of the isolation of orange DNA were measured using NanoDrop. The results showed that the DNA of the three oranges had purity of pomelo yellow oranges 1,83, limes 1.8 and sunkist oranges 1,51. The concentrations obtained from each of the oranges were Yellow Bali Citrus 532 ng / µl, Lime Citrus 664.5 ng / µl and Sunkist Orange 888.6 ng / µl.

PREPARATION OF GEOTHERMAL SILICA GLASS COATING FILM THROUGH MULTI-FACTOR OPTIMIZATION

Glass coating films have been developed by many researchers in recent years. However, mass commercialization of this technology is still inefficient, and optimal methods are needed to produce affordable products. This paper introduces a film preparation method through, which a coating film is superimposed on silica glass by utilizing geothermal waste, a byproduct of geothermal power plants. Geothermal waste has been used as a silica precursor and modified using several silylation agents such as methyltriethoxysilane (MTMS), hexamethyldisilazane (HMDS), polydimethylsiloxane (PDMS), and surface-active agent (surfactant) cethyltrimethylammoniumbromide (CTAB). Design Expert 8.0.6 is used for optimization to find the desired product at the concentration of specific precursors and silane agents using contact angle responses. A model that consists of statistically significant variables can be generalized to a broad data range. The results of this study indicate that the glass surface coated with modified silica produces hydrophobic glass with contact angles up to 90° using the MTMS silylation agent.

Preconcentration and spectrophotometric determination of Fe(III) by cloud point extraction using Zincon as complexing agent

A cloud point extraction (CPE) process was described for the separation and spectrophotometric analysis of Fe(III) in different water samples and blood as chelating agent. The complexation reaction between Fe(III) and Zincon was elaborated at pH 5.0 using acetate buffer and the complex was quantitatively recovered in a mixed micelle system composed of cethyltri methyl ammonium bromide (CTAB) and Triton X-114. This reaction was carried out at room temperature in the presence of 0.05 mol L-1 Na2SO4 as salting-out electrolyte. The linearity was up to 1000 µg L-1. The preconcentration factor was 50. The precision (as relative standard deviation) and the limit of detection were 2.5% and 3.1 µg L-1, respectively. The proposed procedure was used for the spectrophotometric detection of Fe(III) in water and blood samples and the data were statistically comparable to those achieved using ICP-OES technique.

Influence of Pore Structure of Silica Coated on Copper-Zinc Oxide-Based Catalyst for Carbon Dioxide into Methanol

The present work has investigated influence of pore structure of silica coated on copper-zinc oxide-based catalyst for hydrogenation of carbon dioxide into methanol. For controlling the pore structure, micelles of a cationic surfactant, cethyltrimethylammonium bromide (CTAB), was used without and with a swelling agent, 1-dodecylamine, during coating silica on the commercial copper–zinc oxide-based catalyst. The pore structure depended on the amount of the surfactant and the swelling agent, and the specific surface area and the ratio of mesopores of the silica-coated catalyst significantly increased with adding 1-dodecylamine with the surfactant. The silica-coated catalyst prepared both with CTAB and 1-dodecylamine showed the significantly rapid evaporation of physisorbed water on the catalysts, and the property can reflect the catalyst’s high activity and stability for hydrogenation of carbon dioxide into methanol.

Fluoride-free synthesis of mesoporous [Al]-[B]-ZSM-5 using cetyltrimethylammonium bromide and methanol-to-olefin activity with high propene selectivity

Large ZSM-5 crystals containing [B]-sites and mesopores with 2.5 nm pore sizes are synthesized in a fluoride-free, low OH− medium using cethyltrimethylammonium bromide as mesoporogen and 1,6-diaminohexane as structure directing agent. Absence of extra-framework Al sites and low concentrations of silanol sites are evidenced by 27Al MAS-NMR and in-situ FTIR analysis. The low-defect containing [Al]-[B]-ZSM-5 (Mes-[Al]-[B]-ZSM-5) is evaluated for catalyzing the methanol-to-olefins reaction and found to result in low coke formation (4.1 mg g-1 h-1) and very low alkane and aromatic formation rates. The propene to ethene ratio of 4.3 observed using Mes-[Al]-[B]-ZSM-5 is found to be superior to that (1.9) of a nano-sized [Al]-[B]-ZSM-5 (crystal sizes around 36 nm). Small particle sizes for nano-sized [Al]-[B]-ZSM-5 is found to be effective for supplying a higher coke tolerance, but insignificant for olefin product selectivity.

Surface roughness, wear and thermal conductivity of ternary electroless Ni–Ag–P coating on copper substrate

Thermal testing tool used in electronic industries requires a high thermal conductivity and wear resistant coating to ensure efficient thermal transfer over some period of testing cycles. A study on ternary nickel-silver-phosphorus (Ni–Ag–P) coating was carried out by adding silver sulphate into electroless nickel-phosphorus (Ni–P) bath solution with a target to improve thermal conductivity. The results showed that silver can be co-deposited into Ni–P coating but in limited concentration without causing bath decomposition. Cethyltrimethyl ammonium bromide (CTAB) were added into the bath solution as surfactant to improve the coating surface morphology and roughness. Characterization of coatings were done using atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive x-ray (EDX), optical microscope, Knoop microhardness tester, pin-on-disc wear tester and hot disk thermal analyser. When the concentration of silver sulphate added was low, coating produced have smoother surface with improved thickness, hardness and wear resistance. Higher concentration of silver sulphate led to bath decomposition thus coatings have rougher surface with reduced thickness, hardness and wear resistance. Thermal conductivity test showed increment in the thermal conductivity value of Ni–P coating from 445.7 W m−1.K to 466.9 W m−1.K with addition of 10 mg l−1 silver sulphate. It is found that co-deposition of silver at low concentration can improve the hardness, wear resistance and thermal conductivity, and as comparable thickness value is possible, ternary Ni–Ag–P showed interesting potential to replace current NiP coating used in thermal testing tool.

A rapid dispersive liquid-liquid microextraction based on hydrophobic deep eutectic solvent for selective and sensitive preconcentration of thorium in water and rock samples: A multivariate study

Thorium [Th(IV)] and its compounds are highly toxic and cause severe damage to bone and kidney through long term exposures. Conventional methods of Th(IV) detection are complicated and costly. In this study, we developed a new dispersive liquid-liquid microextraction (DLLME) based on hydrophobic deep eutectic solvent (HDES) for preconcentration of Th(IV) in water and rock samples prior to UV–Vis. spectrophotometric detection. The microextraction procedure was carried out by applying thorin as a chelating agent, cethyltrimethyl ammonium bromide (CTAB) as an ion pairing agent and a DES consisted of 1-hexyl-3-methylimidazolium and salicylic acid components as an extraction solvent. Central composite design (CCD) was applied to obtain the best condition of the microextraction procedure. The developed method is a green, facile, fast, selective and sensitive that could detect Th(IV) in the concentration range of 10–600 ng mL−1 with a limit of detection (LOD) and preconcentration factor of 2.1 ng mL−1 and 59, respectively. The relative standard deviation of five replicate measurements of Th(IV) at 100 ng mL−1 was 1.7%. Finally, the proposed method was successfully applied to the analysis of Th(IV) in water and rock samples, and desirable results were obtained.

Design and functionalization of magnetic ionic liquids surfactants (MILSs) containing alkyltrimethylammonium fragment

A series of magnetic ionic liquids surfactants (MILSs) containing alkyltrimethylammonium fragment {dodecyltrimethylammonium bromotrichloroferrate (III) ([DTA][FeCl3Br]), tetradecyltrimethylammonium bromotrichloroferrate (III) ([TTA][FeCl3Br]), cethyltrimethylammonium bromotrichloroferrate (III) ([CTA][FeCl3Br]), and stearyltrimethylammonium bromotrichloroferrate (III) ([STA][FeCl3Br])} were synthesized and characterized by FT-IR, Raman and MS (ESI) spectra. The physical properties including thermal stability, density and magnetic susceptibility were determined, which revealed that the MILSs had good thermal stability (Td > 210 °C) and considerable magnetic susceptibility (xg > 3.2 × 10−5 emu·g−1). The critical micelle concentration (CMC) values of MILSs aqueous solutions based both on electrical conductivity method and surface tensiometry demonstrated that MILSs had better surface active than the corresponding nonmagnetic parent surfactants {dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), cethyltrimethylammonium bromide (CTAB) and stearyltrimethylammonium bromide (STAB)}. Moreover, the surface tensiometry in a magnetic field revealed that the MILSs showed a magnetically induced reduction in surface tension. With surface active and magneto-responsivity bi-functional properties, allow these MILSs pretend to be manipulated noninvasively and reversibly by an applied external magnetic field in further potential applications such as colloid and surface chemistry.

Control of pore size in shell of hollow silica–alumina composite spheres for hydrolytic dehydrogenation of ammonia borane

In the present study, we attempted to control the shell pore size of hollow spheres and investigated the resulting effect on their acidic properties and activity for the acid-promoted hydrolytic dehydrogenation of ammonia borane. Silica shells were formed on polystyrene template particles via sol–gel method, followed by calcination. For controlling the pore structure, surfactants with various molecular lengths (decyltrimethylammonium bromide (DeTAB), cethyltrimethylammonium bromide (CTAB), and stearyltrimethylammonium bromide (STAB)) were used. The shells of all the hollow spheres included monodispersed and well-ordered pores, and the pore size increased with increase in the molecular length of the surfactant. In particular, the hollow spheres prepared with CTAB and STAB consisted of numerous well-ordered mesopores with sharp peaks centered at approximately 2.4 and 2.8 nm, respectively. The molar ratios of the hydrolytically evolved hydrogen to the initial NH3BH3 in the presence of the hollow spheres prepared with DeTAB, CTAB, and STAB were 0.9, 3.0, and 2.7, respectively, which indicated the stoichiometric amount of hydrogen was evolved in the presence of the hollow spheres prepared with CTAB and STAB. The amount and rate of hydrogen evolution depended on the pore structure, and the hollow spheres with well-ordered and appropriate-sized mesopores in the shells showed a large amount and high rate of hydrogen evolution.

An insight into effect of micelle-forming surfactants on aqueous solubilization and octanol/water partition coefficient of the drugs gemfibrozil and ibuprofen

Aqueous micellar solubilization of ibuprofen and gemfibrozil drugs was investigated at constant temperature (25.0±0.1) °C and atmospheric pressure using shake-flask and UV–vis spectrophotometric techniques. The solubility measurement was done in presence of three surfactants possessing different head groups, namely sodium dodecylsulfate (anionic SDS), cethyltrimethylammonium bromide (cationic CTAB) and polyethylene glycol dodecyl ether (non-ionic Brij 35) as well as their binary mixtures. The micellar solubility descriptors of χ (molar solubilization capacity), K (micelle–water partition coefficient), and ΔGs∘ (standard free energy of solubilization) were obtained to estimate quantitatively the solubilization efficiency of the surfactant systems. Moreover, the octanol-water partition coefficient of these drugs was also evaluated in the micellar solutions. The results obtained in the aqueous micellar system demonstrate that, irrespective of the surfactant type, the solubility of drugs increases with increasing the concentration of micelles. It was found that the solubility of ibuprofen and gemfibrozil in Brij 35 and CTAB solutions, respectively is higher compared to that in the other surfactants. However, the partition coefficients of these drugs show an inverse trend with solubility data. Finally, the effect of the surfactant type on solubility enhancement of the drugs is explained in terms of possible interactions between the drug and the micelle.

Surfactant-assisted dispersive liquid–liquid micro-extraction combined with magnetic solid-phase extraction for analysis of polyphenols in tobacco samples

A novel and simple two-step micro-extraction technique combining surfactant-assisted dispersive liquid–liquid micro-extraction and magnetic solid-phase extraction prior to high-performance liquid chromatography was established for analysis of polyphenols including chlorogenic acid, caffeic acid, and scopoletin in tobacco samples. In the developed system, Fe3O4 nanoparticles were synthesized by a one-step chemical co-precipitation method and used to remove hydrophobic substances in tobacco samples by physical adsorption. Low-density solvent (1-heptanol) and cationic surfactant cethyltrimethyl ammonium bromide were employed as extraction solvent and disperser agent, respectively. Under the optimized experimental conditions, a good linearity of the method was obtained over the concentration range from 0.1 to 1000 ng mL−1 for target analytes. The limits of detection (S/N = 3) were 0.05 ng mL−1 for CGA, 0.10 ng mL−1 for CFA, and 0.12 ng mL−1 for SP, respectively. Finally, the applicability of the developed method was evaluated by extraction and determination of these three phenolic compounds in tobacco samples and satisfactory average recoveries of spiked samples were between 96.6 and 102.7%.