mohammadreza ganjali

A nickel/copper benzene-1,3,5-tricarboxylate metal-organic framework (MOF) was prepared through a rapid and effective electrochemical process. The properties of the obtained catalyst were studied with Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and X-ray powder diffraction (XRD). The electrocatalytic behavior of the synthesized catalyst in an oxygen reduction reaction (ORR) was studied with a rotating disk electrode in alkaline media and compared to the catalytic behavior of a platinum commercial catalyst at the same conditions. A comparison of the obtained results showed that the synthesized catalyst showed more current density and positive onset potential than the commercial platinum catalyst in ORR. This work introduces an effective and rapid electrochemical synthesis of high-porosity MOF compounds for advanced electrocatalytic applications.

This article is focused on the development of a sensitive voltammetric electrode for sulfadiazine using nanoparticles of Tb2(WO4)3 to modify a carbon paste electrode (CPE). The behaviour of the modified-CPE was evaluated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and fast Fourier transform square wave voltammetry (FFTSWV). The results revealed an irreversible sulfadiazine oxidation peak around 0.85 V vs. the Ag/AgCl reference electrode. The physicochemical properties of the nano-material were investigated using scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Some effective parameters such as, pH, percentage of modifier, amplitude and frequency on sensor sensitivity were studied and optimized. The analytical curve was then obtained in the concentration ranges of 0.01–1.0 μM and 1.0–100 μM with a detection limit of 4.10 nM by fast fourier transform square wave voltammetry. Also the electron transfer coefficient (α) was determined as a value 0.66 for the sulfadiazine oxidation. The drug analysis in pharmaceutical formulation was also carried out and recovery percentages in the range of 97–102% were recorded. The sensor presented a good reproducibility and repeatability with acceptable RSD values (3.8%, 1.02% respectively) and long-term stability (almost one month).

Diazinon is an organophosphorus insecticide that was widely used in agriculture to control pests on crops. It acts as an acetylcholinesterase inhibitor, which means that it interferes with the normal functioning of the nervous system of insects, leading to their death. Diazinon can also have an impact on human health and the environment, as it can contaminate water and soil and pose a risk to non-target species, including humans and animals. This review paper shows the progress made in the last years in analytical methods applied for the purpose of extraction, detection and degradation of Diazinon as an important environmental pollutant. A variety of sampling and analytical methods have been developed to measure diazinon and its metabolites in different media. The most popular methods for the identification and analysis of Diazinon are liquid and gas chromatography, liquid-liquid extraction, and solid-phase extraction (SPE). The focus of this review is on the identification, measurement, and elimination of diazinon as a major soil pollutant. It begins with a discussion of analytical techniques, followed by an examination of methods for removing diazinon from soil.

The analysis of neodymium and its compounds in various samples is very important, and the application of varied instrumental techniques for this purpose has hence been reported. Accordingly, different electrochemical electrodes have been developed for the analysis of Nd3+ over varied concentration ranges in different matrices. This text tends to offer an overview of these potentiometric instruments with a focus on the structure of the ionophores, as well as the nature and amount of the components used to develop the sensing parts of these electrodes.

Praseodymium is a rare earth element with various applications. The analysis of the levels of the compounds of this elements is very important and various instrumental techniques have been used for the determination of this element in various samples. Among the various techniques used to this end, electrochemical and optical sensors constitute a set of powerful tools for the determination of traces of Pr3+ ions in various samples and concentration ranges. The present review tends to provide an overview on the various potentiometric and optical sensors developed for this purpose, with a focus on the ionophores used and the composition of the sensing elements.

CoMFA and CoMSIA methods were used to perform 3D quantitative structure-activity relationship (3D-QSAR) evaluation and molecular docking, of 5-HT6 receptor inhibitors. The CoMFA model performed on training set in biases of alignment with suitable statistical parameters (q2= 0.556, r2 = 0.836, F= 26.334, SEE=0.171). The best prediction for 5-HT6 receptor inhibitors was obtained by CoMFA (after focusing region) model with highest predictive ability (q2= 0.599, r2 = 0.857, F= 30.853, SEE=0.160) in biases of the same alignment. Using the same alignment, a consistent CoMSIA model was obtained (q2= 0.580, r2 = 0.752, F= 34.361, SEE=0.201) from the three combinations. To evaluate the prediction capability of the CoMFA and CoMSIA models, a test set of 9 compounds was used so that they could show the good predictive r2 values for CoMFA, CoMFA (after focusing region), and CoMSIA models, 0.554, 0.473, and 0.670, respectively. The obtained contour maps form models were used to identify the structural features responsible for the biological activity to design potent 5-HT6 receptor inhibitors. Molecular docking analysis along with the CoMSIA model could reveal the significant role of hydrophobic characteristics in increasing the inhibitors potency. Using the results, some new compounds were designed which showed the higher inhibitory activities as 5-HT6 receptor inhibitors.

In this work, single layered Ti3C2(OH)2 MXene nanosheets have been successfully prepared through a facile approach by etching Ti3AlC2 with alkaline solution treatment (KOH with minimum amounts of water). The structure and morphology of the produced nanosheets were evaluated through X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analysis and the chemical composition was determined using an energy dispersion X-ray (EDX) spectrometer. Methylene Blue (MB) as a target pollutant adsorption and photocatalytic degradation tests were subsequently performed to assess the functionalities of hydroxyl-terminated MXene. MB removal using Ti3C2(OH)2 MXene in the dark in 20 minutes achieved an absorption-desorption balance of 51.2%, and then MB was degraded within 80 minutes under UV light irradiation with great efficiency. Our results presented that the powder of as produced exhibited good photocatalytic activity for three cycles photodegradation. The first-order rate constant (k) was calculated to be 0.0372 1/min. About 97% degradation of Methylene Blue dye in the solution was confirmed within 80 min of exposure to ultraviolet light.

In this work, a new sensitive sensor based on application of fast Fourier transform square wave voltammetry (FFTSWV) for determination of sulfadiazine is described. The developed sensor is a modified carbon paste electrode with Eu2(CO3)3 nanoparticles. The characterization of the used materials was done through transmission electron microscopy (TEM) and FT-IR   spectroscopy. The cyclic voltammogram of sulfadiazine showed a well-resolved irreversible oxidation peak at around 0.85 V vs. Ag/AgCl.  After optimization of experimental conditions, such as pH, percentage of modifier, amplitude, number of cycle and frequency a linear calibration curve was obtained in the concentration ranges of 1.0×10-6 – 250.0×10-6 M with a limit of detection 0.4×10-7 M. The proposed sensor was successfully applied for the determination of sulfadiazine in pharmaceutical sample with the RSD range of 0.7 to 1.7.

Preparation of an efficient hybrid structure photocatalyst for photocatalytic decomposition has been considered a great option to develop renewable technologies for environmental remediation. Herein, ternary magnetic Fe3O4/GQD/g-C3N4 nanocomposite (FGC) was prepared using the ball mill method. Binary nanocomposites Fe3O4/g-C3N4 (F/CN) and GQD/g-C3N4 (G/CN) were prepared to compare photocatalytic activity with FGC. The performance of photocatalysts for degradation of rhodamine B (RhB) was studied. EDX results showed that Fe3O4, GQD and g-C3N4 nanoparticles (NPs) are uniformly distributed in the FGC. The FGC nanocomposite shows superparamagnetic behaviour with a saturation magnetization of 12 emu. g-1, which makes it favourable compound for magnetic separation procedure. Photocatalytic activity of FGC (100%) was much higher than those of the G/CN (88%) and F/CN (77%) photocatalysts. The superior activity of FGC compared to binary composites was attributed to broader absorption in the visible light band and greater suppression of electron-hole recombination. The photocatalytic degradation of RhB using FGC was consistent with pseudo-first-order kinetics. The reusability of FGC was examined for four runs and no noticeable decrease was observed with the same irradiation time for each run. Finally, it can be argued that FGC photocatalyst can be an efficient semiconductor for the degradation of organic dyes from wastewater.

Acrylamide is one of the potential environmental public health problems, resulting from its increased accumulation in the process of cooking foods containing high levels of carbohydrates that are fried or cooked at high temperatures. So, developing a precise and sensitive analytical method for detecting and determining acrylamide in foods is absolutely necessary and inevitable. Gas Chromatography (GC) and Liquid Chromatography (LC) are two main laboratory techniques for acrylamide determination. In this study, we tried to use a cheaper, faster, accurate method for measuring acrylamide in real food samples. P540 and P503 were used as fluorescent reagents to detect the concentration of acrylamide in potato chips samples from 4 companies. Fluorescence spectroscopy was used in this work. The results obtained for the detection of acrylamide in comparison with the HPLC-MS method showed that there is an acceptable overlap between the fluorescence spectroscopy and HPLC method. The amount of acrylamide in four potato chips samples, obtained from the market in Tehran city, was determined using the proposed method. The optimum values of different parameters were determined. Comparisons between two methods, HPLC-MS and fluorescence spectroscopy were also described. The figures of merit for the proposed method were in the ideal range. The developed methods showed a high correlation coefficient (R2= 0.991). According to the results of the fluorescence emission spectroscopy and its comparison with HPLC-MS, the performance and reliability of the proposed method as a simple, efficient, and rapid method with reduction of cost and time for determining acrylamide in potato chip samples were demonstrated.

In this study, the potential of SBA-15/di-urea nanoporous silica compound for the removal of Pb2+ and Cu2+ ions was investigated. The presence of organic groups in the silica framework of SBA-15/di-urea was demonstrated by the FT-IR spectrum. The functionalized product showed the BET surface area 518 m2/g and pore diameter 6.5 nm, based on adsorption-desorption of N2 at 77 K. SEM revealed a rod-shaped morphology, and the TEM image showed an ordered array of 2D hexagonal mesoporous SBA-15. The ions in the samples were identified by flame atomic absorption spectrometry. The effect of adsorbent amount, contact time, metal concentration, pH, and presence of other metals on removal efficiency has been studied. Simultaneous removal of Pb2+ and Cu2+ ions from 20 mL of the sample solution containing 60 μg of each ion were completely done at pH greater than 5.0 after stirring for 15 minutes. Langmuir, Freundlich, and Temkin adsorption isotherms were evaluated for both adsorbates and it was determined that the data fitted well with the Langmuir model (R2> 0.98). The maximum capacity of the adsorbent was found to be 147.0 ± 0.6 mg and 77.0 ± 0.5 mg of Pb2+ and Cu2+ ions/g SBA-15/di-urea, respectively. The lowest amount of 3M nitric acid for stripping the target species from adsorbent was determined as 20 mL. The application of this methodology for the real sample was tested by an Industrial wastewater sample.

Flutamide (4-nitro-3-trifluoromethyl-isobutylanilide) is a synthetic anti-androgenic pharmaceutic compound used in the treatment of prostate cancer. Flutamide is also on the essential drug list of WHO. Determination of flutamide levels in biological fluids or in pharmaceutical dosage is of great importance in clinical medicine. Monitoring flutamide can be done through several sensitive analytical methods such as chromatography, chemiluminescence, spectrophotometry. Since flutamide is an electroactive material, it can be targeted for electroanalysis too. Meanwhile, electrochemical methods are more attended by researchers due to their desirable properties compared with other analytical methods. Designing sensors and biosensors for electroactive drugs may be a new trend in pharmaceutical analyses. Here, the electrochemical methods reported on the determination of flutamide are reviewed. Materials and nanomaterials used in the modification of the working electrodes and the characterization of each method are considered and compared.

Tamoxifen (TAM) is a selective estrogen receptor modulator used in the treatment of breast cancer, women’s infertility and some other endocrine diseases. TAM is a generic medication that is prescribed relatively a lot. Due to the impact of this medication and its side effects, screening TAM level in biological samples and in pharmaceutical formulations are of great importance. Various analytical techniques are developed for the detection or monitoring TAM levels in different matrices. Since TAM chemical structure is able to undergo electrochemical oxidation, electrochemical techniques due to their remarkable features are also considered as analytical methods. Here, electroanalytical measurements of TAM will be reviewed.

Magnetic Fe3O4 nanoparticles coated with thiol functionalized mesoporous silica (TFMS) were prepared and usedas a novel adsorbent for Pb2+ and Ag+ removal. FTIR spectra confirmed the Fe3O4 nanoparticle cores coated with mesoporous silica and indicated the presence of thiol groups on the surface. XRD analyses showed that synthesized adsorbent has a face-centered cubic magnetite phase structure. The best removal results were obtained at pH=5-7 and a stirring time of 15 minutes. The lowest amount of 3M nitric acid for stripping the target species from adsorbent was 40 mL. The data was found to fit the Langmuir model, and the respective maximum capacities of the adsorbent for Pb2+ and Ag+ ionswas 1000.0 (±1.5) µg and 1111.0 (±1.2) µg of the target species per mg of the adsorbent. The developed adsorbent was successfully applied in wastewater samples.

Superoxide dismutases (SODs) are categorized as antioxidant enzymes that are involved in many processes such as stress signalling responses and cell protection against free radical species. The primary function of SOD is the removal of produced radical species like superoxide ions in different physiological processes. There are various isozymes of SODs which are classified according to the metal cofactor in their active sites into four general types of Fe-SOD, Mn-SOD, Cu/Zn-SOD and Ni-SOD. Among metal nanoparticles, gold nanoparticles (AuNPs) are useful for biological purposes as sensing probe for determining critical analysis based on surface plasmon resonance and colorimetric method. In this study, the human Cu-Zn SOD expressed, purified, and its interaction with AuNPs based on a new colorimetric method was investigated.

In this approach, a colorimetric detection method for SOD activity was developed based on the carboxylic stabilized AuNPs.

The Ni-NTA Sepharose affinity column was performed for the purification process of enzyme. Following SOD purification, the enzyme activity in presence of AuNPs due to the possible etching in the presence of free radicals which are produced by riboflavin, methionine, Na2CO3 and potassium phosphate buffer, have been performed. In addition, Fluorescence spectroscopy analysis toward SOD and gold nanoparticle were performed.

Superoxide radicals generated from the enzymatic reaction would preferentially etch AuNPs and resulted in remarkable changes of localized surface plasmon resonance of AuNPs, which is reduced in the presence of SOD. Under the optimized experimental conditions assay (pH~7.8 and 25 ˚C), better selectivity and sensitivity toward SOD activity was shown.

In this context, an indirect new colorimetric method for determining of SOD activity based on gold nanoparticles (AuNPs) was evaluated. According to the presented result, it may be concluded that by scavenging of free superoxide radicals in the presence of SOD, the amount of AuNP absorbance can be replenished.

Phenylalanine dehydrogenase (PheDH) which is categorized in oxidoreductase enzymescatalyzes the NAD+- dependent oxidative deamination of L-Phe to phenylpyruvate.This enzyme has widespread applications in industrial and medical fields such asdetermining the amount of phenylalanine for monitoring of phenylketonuria (PKU). Quantum dots (QDs) are known as semiconductors with many advantages including high photostability, unique optical characteristics, and symmetric emission spectrum.The protein-QD interactions have become an important interest due to its similarity with protein–ligand interactions. These interactions depend on many factors such as protein conformation and orientation and also can be lead to increase or decrease enzymatic activity due to NPs features.In this study, the interaction of B. badius Phenylalanine dehydrogenase (PheDH) and CdTe540 through examining of kinetic parameters of the enzyme for L-phenylalanine and L-tyrosine as substrateswereassessed to understand how this protein can interact with QD. After expression and purification of enzyme in prokaryotic E.coli BL21 host, kinetic parameters of the enzyme such as Km, Vmax, Kcat,Ki and Kcat/km values for L-Phenylalanine and L-tyrosine substrates in the presence and absence of CdTe540 were calculated. The results showed that CdTe could have an inhibitory effect on PheDH enzyme. Fluorescence spectroscopy demonstrated that the binding of QDs with enzyme induced conformational changes in the enzyme in the presence of CdTeQD. It was concluded that a comprehensive characterization of stability of enzyme bound QDs could be a necessary step in their potential use in biomedical fields.

Nowadays, provision of sanitary water is one of the main concerns of the world society, and heavy metals are one of the most important pollutants in water resources. Heavy metals, including copper, can enter the food chain and the body of living organisms and can affect humans through toxic and carcinogenic effects. Therefore, in this study, nanoporous SBA-15 functionalized with di and tetra carboxylic acid was synthesized and used for remove copper ions from aqueous solutions. The adsorbents were characterized by scanning electron microscopy, N2 adsorption-desorption measurements and infrared spectroscopy for investigation of porosity and functional groups of mesoporous silica. Flame atomic absorption spectroscopy was used for determination of ions. Effective parameters on removal process including amount of adsorbent, contact time, pH of solution and presence of other metal ions in the medium, were evaluated and optimized. The best removal efficiency with di and tetra carboxylic acid functionalized SBA-15 was obtained at pH>5 with 10 mg of adsorbent in the stirring time of 15 minutes. The recovery of copper from adsorbents was done with 20 ml solution of nitric acid (3 mol/L). Langmuir and Freundlich adsorption isotherms were evaluated for both adsorbents. According to the Langmuier model, the maximum adsorption capacity of 232.56 and 93.46 mg of copper per gram of adsorbent and correlation coefficients (R2) of 0.857 and 0.9688 for di and tetra carboxylic acid functionalized SBA-15 were obtained, respectively. But, the correlation coefficients (R2) obtained from the fitting of the data using the Friendlich isotherm were 0.991 and 0.972 for di and tetra carboxylic acid functionalized SBA-15 silicas, respectively, which indicates that this model is suitable to explaining the behavior of copper adsorption on both adsorbents. Finally, the removal of copper from real wastewater samples was performed. The results indicate that nanoporous SBA-15 silicas functionalized with di and tetra carboxylic acid are desirable adsorbents for copper ions removal.

Nowadays, there are increasing concerns about pesticides occupational and environmental adverse effects despite the wide use. Therefore, it is very important to develop reliable methods for pesticides detection, extraction, and quantification in different samples. This study was aimed to develop an electrochemical Nano-composite sensor based on molecularly imprinted polymer (MIP) for selective determination of pesticides. The MIPs and non-imprinted polymers (NIPs) for diazinon and dicloran pesticides synthesized and were used in the composition of the carbon paste electrode. The square wave voltammetry (SWV) differential technique based on a fractional 28 factorial design was used to evaluate the effects of variables on the sensor response. The results of MIP-CP electrodes showed very high recognition abilities compared to the NIP-CP. The linear ranges for diazinon and dicloran were obtained 5×10-10 to 1×10-6, 1×10-9 to 1×10-6 mol L-1, and detection limits were 2.7×10-10 and 4.1×10-10 mol L-1, respectively. Modified sensors were provided the prominent selectivity and sensitivity for quantification of pesticides in urine and water real samples considering optimized conditions. Therefore, the special sample pre-treatment wasn’t required prior to the analysis process. The experimental design was verified the existence of interaction between factors. Consequently, the variables including square wave frequency, square wave amplitude, and deposition potential were indicated more significant effects on the sensor response than the other factors. It can be concluded that the interaction evaluation between variables is very important to look for the optimum conditions for pesticides analysis using voltammetric sensors.

In this work, polyamidoamine dendrimer G(1.5) supported on SBA-15 nanoporous is used as a novel sorbent for extraction and determination of Pb2+ and Cu2+ ions from environmental water specimens utilizing flame atomic absorption spectrometry. FTIR spectrum and thermal analysis were used to represent the existence of dendrimer groups in the silica framework. The various parameters like pH, concentration of eluent, extraction time, interfering ions on extraction efficiency were studied. Pb2+ and Cu2+ ions were completely extracted at pH= 5-8 after stirring for 5 minutes. The minimum quantity of acid for stripping the ions from SBA- G1.5 was examined and the pre-concentration factor of the technique was 233 for both of ions. Under the optimized conditions the linearity of the technique was within 10-40 ng mL−1 Pb2+ and 2-20 ng mL−1 Cu2+. Detection limits for Pb2+ and Cu2+ were 5.0 and 1.2 ng mL-1 and the relative standard deviations (RSD, %, C=15 ng mL-1, n=5) were 2.9 % and 2.1 %, respectively. There was a good consistency between the measured and added amount of Pb2+ and Cu2+ in spiked distilled water which shows good accuracy of the method. Capability of the method in real sample was tested in various water samples.

In this study, N-methyl-N'propyltrimethoxysilylimidazoliummodified LUS-1 and MCM-48 nonoporous materials were prepared and employed as adsorbent for removing Reactive Blue-19 from aqueous solutions.LUS-1 and MCM-48 were made based on the previous procedure and modified with N-methyl-N'propyltrimethoxysilylimidazolium chloride. XRD analyses did not show any lattice alteration between modified and unmodified adsorbents. A hexagonal mesophase structure with the P6mm symmetry for LUS-1 and IM-LUS-1, and a cubic Ia3d space group for MCM-48 and IM-MCM-48 were observed. UV/Vis spectrophotometry was used to determine of the dye concentration in the solution. Batch studies were conducted in order to find the optimum adsorption conditions and investigation of different empirical parameters like the pH impact, contact time, the amount of adsorbent, and concentration of dye on adsorption process. The best dye removal efficiency of the adsorbents were more than 93% at pH= 3.0-7.0 after about 3 min for IM-LUS-1 and after 30 min for IM-MCM-48. RB-19 dye was desorbed from both of the adsorbents with 10 mL of sodium hydroxide 2 M during 5 min. There was well match between the data and the Langmuir model with maximum adsorption capacities 476.2 mg/g IM-LUS-1 and 277.8 mg/g IM-MCM-48. The reusability of the sorbents were higher than 4 cycles. In addition, removal percent of RB-19 dye from 50 mL of real textile wastewater with 20 mg of IM-LUS-1 and IM-MCM-48 were 93.0 (± 0.6) and 90.2 (± 0.7), respectively. The results showed that this method might be appropriate for removing the pollutant dyes from textile wastewater.

Ordered nanoporous silica such as SBA-15 has a great potential for application in controlled drug release systems. Chemical modification of the silanol groups of SBA-15 allows better control over drug loading and release. Therefore, tris(2-aminoethyl) amine-functionalized mesoporous silica SBA-15 was evaluated as a potential carrier for the delivery of citalopram.

Tris (2-aminoethyl) amine-functionalized SBA-15 was synthesized and characterized by various methods. Citalopram was loaded on the functionalized SBA-15 and drug release into simulated body fluid (SBF) solution and phosphate buffers was investigated.

The optimal condition for loading of the citalopram was obtained at pH = 9 after stirring for 5 minutes. The release profile of citalopram was monitored in phosphate buffers with three different pH values of 5, 7, and 8. A faster release rate at lower pH value was observed, suggesting a weaker interaction because of the protonation of the amino group of the functionalized SBA15. The average release rate of citalopram from each gram of functionalized SBA-15 was 12 µg h-1 in the SBF.

The results showed that loading amount and release rate of citalopram depended on pH value and the release process showed a very slow release pattern. Therefore, tris (2-aminoethyl) amine-functionalized SBA-15 is a suitable carrier for controlled release of citalopram and has a great potential for disease therapy.

Copper vanadate nanoparticles were synthesized by a simple coprecipitation method in an aqueous medium and the products were used as adsorbents for eliminating methylene blue (MB) from water. The structure and morphology of the produced nanoparticles were evaluated through X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) analysis. The results indicated that the particles were 22-40 nm in diameter. Further, batch adsorption experiments were performed to evaluate the potential capability of the product for the removal of MB and optimizing the adsorption conditions. The effects of pH, the quantity of the adsorbent, contact time, dye concentration, and temperature on adsorption were determined. Fitting of the experimental data into the Langmuir and Freundlich adsorption models revealed good compliance with the Langmuir model with a maximum adsorption capacity of 151.5 mg/g at pH= 4.0. Evaluation of the kinetic and thermodynamic parameters showed that the adsorption process follows a pseudo-second-order kinetic model and reaches equilibrium after 10 min. The desorption of the dye and recycling potential of the adsorbent was also studied.

A potentiometric sensor was made using a non-covalent imprinted nano-polymer for analysis of furosemide pharmaceutical compound. Furosemide is a diuretic drug which is also categorized among the doping agent. The nano-molecularly imprinted polymer (nanoMIP) was prepared through precipitation polymerization, where furosemide was used as a template molecule, acryl amid (AA) as a functional monomer and ethylene glycol dimethacrylat (EGDMA) as a cross-linking agent. The sensor showed a selective and sensitive response to the analyte (the template molecule) in aqueous solutions. The MIP-based sensor responded Nernstian (51.8±0.3 mV decade−1) in a concentration range of 7.5×10-6 to 1.0×10-1 mol L-1 with a lower detection limit of 5.0×10-6 mol L-1. The response time of the sensor was ∼20 s, a high performance and a satisfactory long-term stability (more than 2 months). The proposed sensor has acceptable accuracy, sensitivity and precision to be used for furosemide assay in some pharmaceutical preparations.

Hydrogen sulfide is one of the most important impurities in natural gas. Due to the fact that this gas is hazardous, toxic, corrosive and volatile, therefore, the removal of hydrogen sulfide has been studied using several methods. One of the most known procedures is the adsorption process. In the present study, activated carbon and activated carbon-based composite scaffolds (MOF-5) were used as a cartridge mask to remove hydrogen sulfide from respiratory air.

First, activated carbon (AC) was converted to powder form by ball mill, and AC / MOF-5 composite with 10%, 25%, and 40% MOF-5 to AC was synthesized from the MOF-5 metal-organic scaffold. Then, the rates of adsorption and breakthrough time using a designed setup were tested in two ranges of temperatures, humidities and concentrations. XRD, SEM and BET were used to determine the properties of composite absorbents.  The Aeroqual S500 Direct-reading sensor with 0.01 ppm accuracy was used to measure the exact amount of hydrogen sulfide gas.

The AC/MOF-5 composite showed higher adsorption and breakthrough time compare to the other adsorbents. The Specific surface area (BET), average pore diameter, and total pore volume of the adsorbent were 814 m2 /g, 1.6795 nm, and 0.342 cm3 /g, respectively. The isotherm diagram showed that, according to IUPAC, most of the pore size of this adsorbent was classified in the micro-porous group. The maximum adsorption (mg/gS) and breakthrough time (min) were related to AC/MOF-5(40 Wt. %) adsorbent with 60.41 mg/gS (SD = 1.08) and 56.26 min (SD =2.38) at a temperature of 15 ° C, a concentration of 9.88 ppm (SD = 0.70), a moisture content of 51.06% (SD = 0.15) and a pressure drop of 51.34 mm water. By adding more than 25% MOF-5 metal-metal scaffold to activated carbon, the amount of adsorption, breakthrough time and pressure drop were increased.

AC / MOF-5 composite adsorbent due to its porous structure, high specific surface area, and most importantly, having Zn-O-C groups increased the adsorption rate as well as the pollutant Breakthrough time. However, it showed a relatively higher pressure drop than commercial activated carbon (AC).

Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest.

In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization.

Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 µM/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37°C, high concentration of NaCl (up to 2.5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl-1 of zinc. Biochemical and molecular characteristics are indicative that these isolates are Pseudomonas japonica. As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control.

These findings demonstrated that the potential of P. japonica strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.