نشریه شیمی کاربردی روز
پیاپی 32 (پاییز 1393)

The present study deals with degradation of phenol in industrial wastewater using Pseudomonas putida. Biodegradation process at various initial phenol concentrations ranging from 50 to 200 mg/l was evaluated at different conditions. Phenol removal as single source of carbon at initial phenol concentration of 200 mg/l took place within 22 days. Phenol/ glucose mixture used as dual system to improve phenol degradation. The presence of glucose as supplementary substrate degraded phenol at initial concentration of 200 mg/l within 19 days. Acclimated Pseudomonas putida was able to degrade phenol at initial phenol concentration of 200 mg/l within 15 days. It was also revealed that phenol degradation using acclimated Pseudomonas putida immobilized on chitosan was carried out at the shortest period of time in contrast to the other conditions. The obtained results represented that microorganism was able to consume phenol as a substrate.

The biosorption of reactive azo dyes (Direct red 81) found in textile wastewaters by activated carbon prepared from sonchus fruit plant has been investigated. Batch experiments were carried out for the biosorption of dyes molecules onto biosorbent at different temperature. The biosorption kinetics was found to follow pseudo- second order kinetic model with high degree of correlation coefficient (R2>0. 99). The equilibrium isotherms of biosorption and kinetics were studied. The biosorption equilibrium data were analyzed by using Langmuir and freundlich isotherm models and the results have shown that biosorption behavior of this dye could be follow to Langmuir isotherm model. Various parameters such as contact time، initial dyes concentrations، temperature، stirring speed and does of biosorbent were taken into account، and promising results were obtained. Furthermore، it was also found that the sonchus fruit plant can using as a low cost material for azo dye biosorbtion.

Quantitative structure-activity relationship (QSAR) models were constructed in order to predict the anti-HIV activity of a set of phenethyl thiazole thiourea (PETT) analogs by calculated descriptors. Molecular descriptors calculated by Dragon software were subjected to variable reduction using the stepwise regression. The variables were then used as inputs for QSAR model generation using multiple linear regression (MLR) and artificial neural network (ANN). Validation study of the MLR and ANN models was performed using the test set and leave-one-out techniques. The results obtained for prediction of the test set by the MLR and ANN models showed squared correlation coefficients of 0. 766 and 0. 913، respectively.

In this study we report synthesis and application of NiO nanoparticle (NiO/NPs) carbon paste electrode (NiO/NPs/CPE) as high sensitive sensors for voltammetric determination of Nalbuphine (NB). The NiO/NPs was characterized with different methods such as SEM and XRD. The cyclic voltammogram showed an irreversible oxidation peak at 0. 57 V (vs. Ag/AgClsat)، which corresponded to the oxidation of NB. Compared to common carbon paste electrode، the electrochemical response was greatly improved. The electro-oxidation of NB occurred in a pH-dependent 1e− and 1H+ process، and the electrode reaction followed a diffusion-controlled pathway. Under the optimum conditions، the voltammetric oxidation peak current of NB showed linear dynamic ranges with a detection limit of 0. 5 μM for NB. The novel sensor has been found selective and successfully implemented for the determination of NB in water، serum and urine samples.

Nano tin dioxide was employed as a catalyst for efficient and facile preparation of pyran derivatives via the one-pot three component condensation reaction of various aldehydes with malononitrile and dimedone. Chromene derivatives via the one-pot three component condensation reaction of various aldehyde with malononitrile and 4-hydroxycoumarin were also synthesized by this novel catalyst. The described novel synthesis method proposes several advantages of mild condition، safety، high yields، short reaction times compared to the traditional method of synthesis.

The present study was carried out to investigate the effect of silver nanoparticles to catalyzed peroxydisulfate in order to removal of Acid Red 87 from contaminated water، the simultaneous use of peroxydisulfate and nanosilver significantly increased the removal efficiency. The effects of various parameters such as Peroxydisulfate concentration، contaminant concentrations and dosage of silver nanoparticles on the dye removal were evaluated. Results showed that increasing the concentration of peroxydisulfate and nano-silver catalyst can increase the rate of pollutants removal. The optimal amount of nanosilver and the optimum concentration of peroxydisulfate were estimated 0. 125g. L-1 and 10 mM، respectively.

A one-pot synthesis of novel derivatives of bis-chalcones by condensation of prepared bis-aldehyde and different ketones in basic media have been described. Compounds were characterized by IR، 1H NMR، 13C NMR and EI-Mass spectra. The antibacterial activities of bis-chalcones were evaluated against Staphylococcus Aureus، Escherichia coli، Pseudomonas aeruginosa and Bacillus subtilis. Biological data indicated that some products exhibit promising activities. A significant reasonable reaction time، a nearly quantitative yield، and high atom economy in the product were observed. The simplicity of the reaction، ease of execution، simple workup، and good yields، with the use of easily accessible starting materials is hallmarks of this process.

The thiosemicarbazone compound، (E) -2- (2،3-dimethoxybenzylidene) -thiosemicarbazone (23-MBTSC)، derived from the reaction of 2،3-dimethoxybenzaldehyde and thiosemicarbazide in ethanol solution has been synthesized and characterized by elemental analyses (CHN)، FT-IR and 1H-NMR spectroscopy and X-ray single-crystal diffraction. Molecular geometry from X-ray experiment of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G basis set. Calculated results show that Hartree-Fock (HF) and density functional theory (DFT) can well reproduce the structure of the title compound. In the gas phase the four conformers for the title compound were found and it was found that the conformer A is the most stable one. Molecular packing can be viewed as a dimer held together by two N-H•••S and one C-H•••S intermolecular hydrogen bonds. In addition، C-H•••N and C-H•••S types of intermolecular hydrogen bonds also help the molecules in the crystal packing. The title compound crystallizes in the monoclinic space group P21/c with unit cell parameters: a = 21. 7380 (7)، b = 6. 8748 (10)، c = 16. 8243 (5) Ǻ، β = 112. 754 (3) °، V = 2318. 62 (12) Ǻ3 and Z = 8.

A spectrofluorimetric method is proposed for the determination of Daunorubicin (DNR) based on its quenching effect on the fluorescence intensity of Tb3+- deferasirox (DFX) complex as a fluorescent probe. The excitation and emission wavelengths were 328 and 545 nm، respectively. The optimum conditions for the determination of DNR were investigated considering the effects of various parameters on the quenched fluorescence intensity. In the optimum conditions the decrease of the fluorescence intensity of the system showed a good linear relationship with the concentration of DNR in the range of 15-1100 μg L-1، with a correlation coefficient 0. 998. The detection limit (3s) was 4. 3 μg L-1 and the relative standard deviation for four replicate determinations of different concentrations of DNR was in the range of 1. 6–4. 7%. The procedure was successfully applied to the determination of daunorubicin in spiked urine and serum samples.

Nanostructured CeO2 powders were synthesized via a series of hydrothermal and solution precipitation methods. Three different hydrothermal methods including 1:2 and 1:1 Bi: Ce molar ratios at 180 °C for 48 h (S1 and S2، respectively) without calcinations; and 2:1 Bi: Ce molar ratio at 180 °C for 48 h with calcinations (S3) were performed successfully for the synthesis of the target nanomaterials. Two different solution precipitation methods i. e. 1:1 Bi: Ce molar ratio at 80 °C for 40 min without and with calcinations (S4 and S5، respectively) were also used for the synthesis of CeO2 nanoparticles. Bi (NO3) 3 and (NH4) 2Ce (NO3) 6 were used as raw materials. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique. CeO2 crystallized in a cubic crystal structure with cell parameters of a=b=c= 5. 412 Å. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM). The technique showed that the morphology of the synthesized nanomaterials were strongly dependent on the synthetic procedure.

In this study، Air-agitated liquid–liquid microextraction (AALLME) with low solvent consumption was demonstrated for gas chromatographic determination of some polycyclic aromatic hydrocarbons (PAHs) as carcinogenic and mutagenic compounds in aqueous samples. Factors affecting the extraction process، such as extracting solvent type، extracting solvent volume، number of agitation، ionic strength، and centrifugation time، were investigated thoroughly and optimized. Under the optimized conditions، the method provided a good linearity in the range of 0. 05 to 120 ng mL-1 (R2 ≥ 0. 995)، low limits of detection (0. 015 to 0. 05 ng mL-1)، good repeatability of the extractions (RSDs below 9. 8%، n = 5)، and the enrichment factors (EFs) were found to be in the range of 327 to 773. This is the first report on the utilization of AALLME for extraction of PAHs and results showed that AALLME can be a good choice for efficient micro-extraction of these compounds. In order to investigate this common view among some of people that hookah smoke can be healthy due to passing through water، both the hookah water and the hookah smoke were analyzed.