Iranian Journal of Analytical Chemistry
Volume:9 Issue: 2, Summer and Autumn 2022

Danofloxacin (DNF), a synthetic fluoroquinolone, is widely used as an antibacterial agent against a broad spectrum of pathogens. In the present study, the effects of DNF on the structure of bovine serum albumin (BSA) were investigated using UV-Vis absorption and fluorescence spectroscopy, and molecular docking methods at different temperatures. The obtained results of UV-Vis absorption studies showed that the microenvironment of the fluorophore residues does not significantly change upon interaction with DNF. Also, fluorometric studies revealed BSA-DNF complex formation and fluorescence quenching of BSA in the presence of DNF. The number of binding sites and binding constants were calculated to be ~1 and in the order of 103, respectively. According to thermodynamic parameters, van der Waals forces and hydrogen bonding play the main role in the BSA-DNF complex formation, which is a spontaneous process. The binding distance between DNF and BSA was calculated by the Förster resonance energy transfer (FRET) method. Molecular docking results were in agreement with thermodynamic and spectroscopic data and confirmed the binding mechanism of DNF to BSA.

In this study, a novel and efficient solid phase extraction method based on the use of γ-alumina (γ-Al2O3) nanoparticles coated with sodium dodecyl sulfate and modified with (E)N'-(2-hydroxy benzylidene) isonicotinohydrazide (H2L) as a new adsorbent was developed for separation and determination of trace amounts of copper(II) prior to flame atomic absorption spectrometry (FAAS). The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with (H2L). The separation procedure was studied with regard to experimental parameters such as pH, amount of sodium dodecyl sulfate , ligand’s concentration, contact time, type and volume of eluent and stirring rate. The effects of interfering ions on the extraction procedure were also investigated. Under the optimum experimental conditions, the extraction efficiency was 98, 97 and 95.5 with relative standard deviation lower than 5% for Shurabil Lake, the collected water behind the barrier and Baligluchai River, respectively. Noticeably, the method has been successfully applied for the extraction and determination of copper content in some real samples.

A new potentiometric sensor based on a β- cyclodextrin modified carbon paste electrode (CPE) was designed for the determination of the captopril drug. The effect of various cyclodextrins (α, β and γ- cyclodextrins) and their percentage, binder agent and ion additive on the potential response have been investigated and the electrode with the best potential response was found. The linear concentration range for this electrode was 7.0×10-7-1.0×10-1 M with a low detection limit of 2.0 × 10-7 M. The effect of pH and temperature on the Nernstian slope was also investigated and the optimal range was obtained. The selectivity of the captopril CPE to interfering species including Li+, K+, Ni+, Mg2+, Ca2+, Co2+, Cr2+, Cr3+, Zn2+,Mn2+, Fe2+, F-, Cl-, SO42-, C2O42- PO43-, C2O42-, ascorbic acid, uric acid, glucose, D-fructose and sucrose was determined by Separate Solution (SSM) and Matched Potential Method (MPM) methods. Finally, the proposed electrode was tested for measuring captopril in drug formulation, blood serum, and urine samples.

In this current article, a chemical sensor was synthesized PbS functionalized with Gelatin Quantum Dots for Fenpyroximate. The measure of Fenpyroximate was performed using concentration (2.5×10-3 mol L-1), PbS Quantum Dot-Gelatin nanocomposites sensor, pH 6, and time 40 s, wavelength 328 nm. Under the optimum conditions, the detection limit linear range were obtained (0.02 to 20.0 µg L-1). The standard deviation of less than (2.0%), and detection limits (3S/m) of the method (0.02 µg L-1) for determination of Fenpyroximate, was obtained. The observed outcomes confirmed the suitability recovery and a very low detection limit for measuring the Fenpyroximate. The chemical PbS Quantum Dot–Gelatin nanocomposites sensor as excellent sensor in the practical application of Fenpyroximate related to residue management is in surface water samples.

In the present study, synthesis of silver nanoparticles and its antibacterial activity were investigated. Silver nanoparticles were rapidly synthesized using leaf extract of beet sugar leaf the formation of nanoparticles was observed within 1 hr. The results recorded from UV–vis spectrum, Transmission electron microscopy (TEM) and X-ray diffraction (XRD) support the biosynthesis and characterization of silver nanoparticles.  The UV-Visible spectrophotometer was indicated absorbance peak in range of 435-440 nm. From high resolution transmission electron microscopy (HRTEM) analysis, the size of the silver nanoparticles was measured 35–40nm. Further, the antibacterial activity of synthesized silver nanoparticles showed effective inhibitory. It showed that antibacterial activity increased by addition concentration of silver nano particle. The 0.008 molar concentrations of AgNPs, antibacterial activity was higher than other concentrations. Results confirmed this protocol as simple, rapid, one step, and eco-friendly, nontoxic and alternative conventional physical/chemical methods. Nanoparticle synthesis is a novel research are to search for an eco-friendly manner and green materials for potential applications in the fields of medicine and drug delivery.

Topological indices are graph invariants used in theoretical chemistry to encode molecules for the design of chemical compounds with given physicochemical properties or given pharmacological and biological activities. Szeged index ( ) and Revised Szeged index ( ) of molecular graph identify some distance properties for graphs. In computational chemistry and graph theory, ( ) and ( ) were more available to test the characteristics of chemical molecular structures, and thus widely used in chemical applications. In this paper, a simple algorithm is presented for constructing the distance matrix. This algorithm is designed for calculation of  and .

The purpose of this study was to create, optimise, and validate a high-performance thin layer chromatographic (HPTLC) method for identifying Molnupiravir (MOL) and its impurity (IMP-MOL). (3aR,4R,6R,6aR) -6-(4-(hydroxyamino) -2-oxopyrimidin-1(2H)-yl) Molnupiravir A is 2,2 dimethyltetrahydrofuro [3,4-d][1,3]dioxol-4-yl)methyl isobutyrate (MOL IMP) Over concentration ranges of 0.1 µg/band to 0.6 µg/band and 0.02 to 0.6 µg/band, the proposed technique was employed to analyse Molnupiravir and its impurity, with mean percentage recovery of 99.92% ±1.521 and 99.28% ±2.296, respectively. This method has been done with the separation of two components and ends with the densitometric measurement of the separated peaks at 276 nm. The separation was done on silica gel HPTLC F254 plates with a Toluene: n-Butanol: Methanol: Water developing system (5:3:1.5:0.5, by volume). The MOL was kept under conditions like oxidative, hydrolytic, thermal stress, and photolytic tests that the International Conference on Harmonization (ICH) requires. In acid, alkali, and oxidative hydrolysis, the MOL was unstable, but it was not affected by acidic, heat or UV light. The alkaline degradation of Molnupiravir was studied using the proposed HPTLC approach. The degradant are separated using HPTLC method, and their structures are confirmed using IR, MS, and NMR spectrum data.

Removal of cobalt from zinc electrolyte solution is one of the most important and difficult steps in zinc production using hydrometallurgy method. The impact of initial concentrations of cobalt, manganese, and Fe and amounts of potassium permanganate on the efficiency of cobalt removal by potassium permanganate from zinc electrolyte solution was investigated in this research. The results indicated that the higher the initial concentration of cobalt, manganese, and Fe is, the lower the cobalt removal amount will be; however, as the amount of potassium permanganate increases, the efficiency of cobalt removal will enhance. It was also found that, in order to make a permissible level of the dissolved cobalt, the consumption of potassium permanganate should be increased as the concentration of cobalt, Fe, and manganese increases. If the concentration of manganese is more than 500 mg/L, it can impact the reduction of the efficiency of cobalt removal to a great extent; but when the initial concentration of cobalt is high, the significance of the impact of the initial amounts of manganese would decrease. Additionally, if the manganese concentration is less than 200 mg/L, the optimal removal of cobalt (less than 2 ppm) will not occur under any circumstances. The results also indicate that if the potassium permanganate concentration is 1 g/L or lower, the Fe ions in the solution will drastically reduce the cobalt removal efficiency.

In this study, we used a prepared from chitosan-capped AuNPs for the determination of trace amount acetaminophen drug in various matrices such human fluids by kinetic spectrophotometric method. The calibration curve was linear in the range of (0.05 to 10.0 µg L−1). The standard deviation of (1.9%), and detection limit of the method (0.05 µg L−1 in time 6 min, 325 nm) were obtained for Sensor level response chitosan-capped AuNPs with (95%) confidence evaluated. Observed outcomes confirmed the suitability recovery, and a very low detection limit for measuring the acetaminophen drug. The method introduced to measure acetaminophen drug in real samples such as urine, and blood can be used for other drugs, and hospital samples.

In the present study a combined analytical method involving ultrasonic extraction (USE) and headspace liquid phase micro extraction (HS- LPME) was used to extract methyl tert-butyl ether (MTBE) in fish tissue for analysis by gas chromatography (GC). Extraction of MTBE from 2 g of fresh fish tissue was performed by ultrasonication for 10 min (in 25 ºC after 3.5 h maceration) in the glass barrel that was filled with water and sealed. Headspace solvent microextraction was done for the extraction of MTBE after centrifuge of sonicated sample. The optimized method (under the optimal experimental conditions: ultrasonic extraction time: 10 min, ultrasonic extraction temperature: 25 °C, fish particle size: a particle of 2 grams, media: distilled water, maceration time: 3.5 h and centrifuge of sonicated sample: 2500 rpm in 15 ˚C for 10 min) had good linearity (R2 >0.99) over the range 0.5- 50 µg g-1, and showed satisfactory level of precision, with RSD values in the range of 1.1 to 9.7 %. The LOD about 0.2 µg g-1 was obtained.

Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This strategy results in increased surface area, the potential to increase saturation solubility, and decreased diffusional distance, all of which lead to an increase in the extent and the rate of dissolution. The purpose of this research was to develop antisolvent precipitation system for the preparation of stable aqueous suspension from ultrafine particles of lamotrigine as a poorly water soluble drug. Use of high stream velocities enhances mixing of lamotrigine acetic acid solution with water, that water was containing of polymer or surfactant inhibitor, was prepared a solution with lamotrigine particles with size <250 nm. Several experimental parameters, such as the type of stabilizer, the concentration of stabilizer, the concentration of salt (NaCl) and the concentration of drug that affected on size of the particles were optimized by undertaking Taguchi experimental design methodology. Using different analytical tools, such as X-ray diffraction (XRD), dynamic light scattering (DLS) and differential scanning calorimetry (DSC), the effect of different parameters on the size of the produced particles was investigated. The results showed that the best stabilizer is PEG (poly ethylene glocal) 4 mg ml-1, concentration of lamotrigine 10 mg ml-1 and NaCl concentration: 2 mol L-1, that the produced submicrometer suspension had a mean particle size of 248.5 nm and size distribution 243.9 – 252.2 nm.

In this study, a new colorimetric sensor based on a couple of Congo Red (CR) and Alizarin Red S (ALRs) was ready for the detection of the carbonate in tracing levels in aqueous media. The linear range of carbonate derived from the results of this simple, selective, and rapid determination, was 1.21 × 10-6–9.51 × 10-5 mol L-1 with the detection limit of 1.31 × 10-7 mol L-1. In the examined cases, the concomitant cations, anions, and weak acids ( I-, Br-, F-, Cl-, SCN-, SO32-, S2O32-, S2O82-, OAc-, H2PO4-, HPO42-, NO3-, C2O42-, HCO3-, BrO3-, IO3-, Cit3-), ( K+, Na+, <1.5 × 10-4 mol L-1 ) did not curb the analysis by creating the disturbance of chemical ions. The recoveries shown in the range of 98.6–102.5% indicate the high validity of the method in water samples. Typically, this compound presented was affordable and fast, with a trouble-free operation, which can consider as a good carbonate receiver in running water greenhouses and arable land. In addition, due to the sophisticated modifications made to filter paper strips, this chemical sensor has the potential capacity to be used as a carbonate solid colorimetric indicator.

In the present study, a novel sorbent-based microextraction method was developed for the quick extraction of ochratoxin A from food samples. The extraction was performed based on graphene-reinforced fabric phase sorptive extraction (FPSE) followed by HPLC-FLD analysis. Chromatographic separations were performed on a C18 column with H2O: ACN: acetic acid (49:49:2, v/v/v) as mobile phase at a flow rate of 1.0 mL/min and with fluorescence detection (λex= 333 nm and λem= 447 nm). The effect of graphene in the sol solution, extraction time, ionic strength, solvent extraction volume, desorption time, and desorption solvent type and volume were evaluated to obtain the maximum extraction efficiency. The optimum condition was obtained at pH=7, 40 mg of graphene per 10 mL of sol solution, 40 min for extraction time and 20 min for desorption time, the best solvent for desorption was 1 mL of ACN: HOAC (95:5 V/V) and extraction volume was 10 mL. The method showed a linear range of 2.0-17.5 ng/mL with a correlation coefficient greater than 0.97. The limit of detection and limit of quantification were found 0.49 ng/g and 1.49 ng/g, respectively with absolute good recoveries (67.7-104.0%) and low relative standard deviations. In addition, ochratoxin A was quantified with the developed method in wheat and chickpea samples and the results indicate the effectiveness of the presented method.

Evaluation of plant responses under different environmental conditions is a principal step towards a better understanding of their function and performance. In this investigation, cumin (Cuminum cyminum), which is known as an important medicinal plant, was examined under three different growing conditions including natural habitat, field and greenhouse conditions in order to clarify the effects of growing conditions on essential oil properties. Essential oil (EO) content was higher in natural habitat samples, but the composition of EO was varied along the three samples extracted from the above three conditions. Overall, 17 compounds were detected and the key component in all samples was thymol, with the highest amount of 18.03% in natural habitat samples. Cuminaldehyde, γ-terpinene, α-thujene and limonene were other substantial compounds of the EO. Some elements were not detected in all samples such as p-cymene which was not extracted from the EO of natural habitat sample and acetoxylinalool which was not observed in greenhouse sample analysis. Regards to phenol content, natural habitat samples showed the highest amount and the lowest value was obtained on field sample. Radical scavenging activity of EO was also higher in natural habitat samples and with respect to phenolic content analysis, it could be considered as a substantial advantage rather than the others. To sum up, results indicated some advantages of natural habitat samples, although field samples also showed superiority in some parameters.