Journal of Applied Research in Chemistry
Year:2013 | Volume:7 | Issue:2|Papers Count:9

Ultrasound-assisted emulsification microextraction followed by gas chromatography-flame ionization detector (USAEME-GC-FID) was used for determination of thymol in natural honey and mouthwash solution. The effects of various parameters affecting the extraction efficiency, including volume of extraction solvent, salt concentration, emulsification time, and temperature were investigated simultaneously by a full factorial design. The results showed that all factors were significant. In the next step, the optimal conditions were obtained by using a small-central composite design as 73.0mL for volume of extraction solvent, 1.50 (w/v%) for salt concentration, 45oC for emulsification temperature, and 9 min for emulsification time. The limit of detection (LOD) was 0.001 mg ml-1. The linear dynamic range (LDR) was 0.01-50mg ml-1 with determination coefficient (R2) of 0.9994. The relative standard deviation (RSD %) was 1.22 %. Comparing with other previously reported studies, the proposed method is an efficient, fast, simple, low cost, and good alternative for determination of thymol.

This paper relates to an experimental investigation of the waste water treatment from a sweetening water unit with high salinity contents. The presence of salt contents leads directly to detrimental effects on environment, however, this can be avoided by using such a process. So, the superiority of this work is to introduce a feasible and viable desalination method.Some experiments have been conducted using chemicals to obtain zero discharge desalination water and salt as valuable direct products.  The quality of produced water is very high because the evaporation is utilized.The variables of a pre-waste water treatment process from an effluent of Mobin petrochemical plant are studied. The work is investigated both theoretically and experimentally in a pilot plant scale. Finally, the optimal values are determined and reported.According to the proposed pre-waste water process, the hardening elements can be removed and the waste water becomes ready for separation of salt from water easily. The type and the amount of flocculants, mixer velocity (rpm), the required reactor, and the ratio of hardeners to flocculants are determined.

5, 5-Diphenylimidazolidine-2,4-dione, known as phenytoin, is an anticonvulsant drug which is useful in the treatment of grand mal and psychomotor seizures. We herein report a facile, safe and improved protocol for high yield preparation of phenytoin by using a green solvent (water). Benzil, which is prepared from the condensation of two moles of benzaldehyde in the presence of catalytic amounts of thiamine (vitamin B1), is the primary substance for this preparation. The procedure is then followed by using Cu (II) ions and ammonium nitrate for oxidation of benzoin to benzil. Phenytoin is finally prepared in 83% yield from benzil and urea in the presence of 30% w/v sodium hydroxide. The purity of the recrystallized. product is verified by experiments based on the USP pharmacopoeia.

By use of a selected glass reference and the addition of nucleating agents like WO3 and Fe2O3, SiO2-CaO-Na2O system of glasses heat treatment, crystallization behavior and thermal properties were considered. In this investigation, frit products of molten glass quenched after milling, converted to minimum particle size and then heat treatment carried out at 710-900oC temperature range with 5oC/min heating rate for 3h.The crystallization temperature range was determined by differential thermal analysis (DTA).The behavior of the range of crystallization for prepared glasses were considered by means of X-ray diffraction. Improvement of thermal properties and sintering behavior of glass-ceramic with 5, 10 and 15 percent of aluminium titanate were studied. The crystallization behavior and thermal properties of SiO2-CaO-Na2O system of  glasses in glass gel with Fe2O3 and WO3 considered as additives showed that the main crystallization phases in all fully sintered glass matrix composites were wollastonite, aluminium titanate, rutil and alumina. It was also revealed that the addition of 15 wt.% aluminium titanate increased the relative density and decreased the thermal expansion coefficient (TEC) (6.9519×10-6/oC) in comparison with the other selected composites.

 Chitosan samples with different molecular weights (Mw) and degree of deacetylation (DD) were prepared by controlling operating conditions through multistage alkali treatment. The temperature of reaction, time duration, and number of reaction steps were considered as effective parameters. A database was developed for chitosan preparation in order to achieve high degrees of deacetylation and control over the molecular weight of chitosan without changing other molecular structures. The number of treatments and the duration of each step of deacetylation significantly affected molecular weight so that two samples were obtained with the DD of 99% and two different molecular weights ranging from 4.66×105 to 2.93×105. Based on the results, the highest molecular weight obtained using the multistage treatment without decreasing DD was 5.32×105 with the DD of 96.67%. Also, the morphological studies indicate that molecular weight of chitosan has significant effect on pore size of the prepared scaffolds, although its quantity is critical.

With the rapid population increase, the importance of using recycled water has increased the serious crisis of water resources and drought. One of the common methods for removal of pollutant is the process of adsorption by the adsorbent. In this study mesoporous carbon CMK-3, was synthesized, characterized and applied in the process of azo dye Janus Green B. Mesoporous carbon CMK-3 was prepared by using SBA-15 silica material molecular sieve as hard template. Finally this adsorbent was characterized and confirmed by using X-Ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscope images (SEM), and chemical analysis (EDX).The effect of contact time, pH, initial dye concentration, electrolyte concentration, and temperature on the removal process of absorbing dye solution was studied. The dye adsorption equilibrium was rapidly attained after 60 min of contact time. Removal of dye in basic solutions was better than in acidic solutions. The adsorption of dye increased with increasing initial dye concentration and salt concentration, but color removal decreased with increasing temperature.

Chitosan nanoparticles can be applied as drug delivery systems. Investigation was carried out to elucidate the influence of process parameters on the mean particle size of chitosan nanoparticles produced by spontaneous emulsification method. The synthesis method of chitosan nanoparticles was optimized using a 3-factor, 3-level Box-Behnken experimental design. This design was used in order to achieve the minimum size and suitable morphology of nanoparticles. Field emission scanning electron microscopy (FE-SEM) was used to determine particle size and morphology of chitosan nanoparticles. The prepared nanoparticles have an average particle size from 33.64 to 74.87 nm. Drug loading in the nanoparticles as drug delivery systems has been done according to the presented optimal method, and appropriate capacity of drug loading was determined by ultraviolet spectrophotometry. Chitosan nanoparticles as drug delivery systems were characterized by Diffuse Reflectance Fourier Transform Mid Infrared Spectroscopy (DR-FTMIR).

Surfactants are as the main part of detergent industries’ wastewaters. It has been reported that the ionic surfactants in the effluent of detergent based industry amounts to about 10 million ton per year, in which 60% are anionic surfactants. There are many physico-chemical methods for the removal of these pollutants. However, the adsorption method is applied in this process.In this study, two adsorbents have been used for removal of LABSNa, i.e. activated carbon and perlite. Effective parameters in adsorption, such as pH, time, temperature, and concentration have been investigated.Optimum condition was obtained after 10 min, at surfactant concentration of 20 mg/L, pH 7, and temperature of 25oC for 0.8 g activated carbon. The optimum condition was also acquired for perlite that has not been effective on the adsorption of LABSNa. Based on the results, the usage of activated carbon in industrial scale is proposed as the application of perlite is compatible for the adsorption of trace pollutant compounds.