Chemical Methodologies
Volume:7 Issue: 5, May 2023

In this paper, pure and Cr-doped SiO2 was prepared by sol-gel method and deposited on glass substrates by dip-coating and calcination of the resulting thin films at 500 °C. An X-ray diffraction examination was performed for the pure and doped films, where we note the appearance of a spectrum in the form of a wide band at the equivalent Bragg angle at 2θ = 22.6°, which indicates that the obtained material is amorphous silica. After that, field emission scanning electron microscopy was conducted to study the morphology of the pure SiO2 thin layer doped with chromium, as it appears that the prepared film is of good quality and free of cracks and holes, as we note that the crystals adopted certain geometric shapes with different sizes and shapes. Likewise, the particle distribution is uniform with the spherical shape. By examining the atomic force microscope to study the surface topography and roughness, we notice that the surface roughness increases with the increase in the doping percentage, where the surface roughness values ​​of the samples vary between (2.94-5.22) nm, and we will get the highest surface roughness values ​​at a concentration of 9%. After preparing the SiO2 nanoparticles, they are mixed with the pigment and deposited on the glass substrates using the dip-coating method to measure the contact angles and study the duration of the effect of SiO2 particles on the pigment. In addition, by measuring the contact angle between a drop of water and the coating surface, we notice that the contact angle increases after adjusting the coating by adding pure SiO2 doped with chromium and mixed with the pigment, as the contact angle increases from (95.71°) to (107.17°) depending on the surface roughness. The surface roughness and its energy are important factors affecting the contact angle.

In the present work, a very sensitive, reliable, and simple spectrofluorometric procedure was improved for concurrent determination of ofloxacin, enrofloxacin, and levofloxacin in the absence of separation treads. Despite a spectral cover, a part of fluoroquinolones have been concurrently resolved by chemometric come near to involving principal component analysis artificial neural network and partial least squares. Artificial varieties mixtures of fluoroquinolones were evaluated and the results acquired by the implementations of these chemometric approaches were evaluated and compared. It was found that the principal component, artificial neural network method provided relatively better accuracy than that of PLS method. This method was applied satisfactorily for determining mixtures of fluoroquinolones in tilapia, chicken samples, and synthetic samples (with concentration ranging over 0.05-1.1 µg/mL for ofloxacin as well as 0.06-0.6 µg/mL and 0.01-0.23 µg/mL for enrofloxacin and levofloxacin), respectively. The suggested method enables detection limits of 0.04, 0.01, and 0.009 µg/mL for ofloxacin, enrofloxacin, and levofloxacin, correspondingly. The recoveries in the tilapia and chicken matrices ranged from 114% to 92%. All experiments that needed to be repeated were repeated 4 times.

In this work, the Soxhlet extraction method extracted the Catharanthus roseus plant to obtain alkaloids, and then converted them into Chitosan nanoparticles (CSNPs)-linker-alkaloids compound. The CSNPs- linker-alkaloids compound was characterized by X-ray diffractometer (XRD), which shows the sample has an orthorhombic structure with crystallite size in nano-dimension; in Fourier Transform Infrared spectroscopy (FTIR), a new distinct band appears at 1708.93 cm-1 which is attributed to C=O esterification, which indicates the success of the reaction. Scanning electron microscope (SEM) images show that the final product has two shapes, spherical particles and tubes in nano-dimensions, and is close to each other compared to normal Chitosan. The cyclic voltammetric technique was used to study the electrochemical analysis of the newly modified electrode with extract plant and CSNPs-linker-alkaloids compound on the glassy carbon electrode. Citrate-Phosphate buffer, KCl electrolytes at pH 5, 20 cycles, buffer volume to 1000 μl and 0.5 Vs-1, the extract plant, CSNPs-linker-alkaloids storage for six months conditions are considered. The modified electrode was used to detect cadmium (Cd) ions in the range of (0.02 and 0.16) ppm. The best was sensitivity R² equal to 0.98 for oxidation and 0.975 for reduction. The modified electrodes; (GCE/extract plant( and )GCE/CSNPs-linker-alkaloids) act as suitable sensors for heavy metals detection in water.

The present study aimed at synthesizing new anti-inflammatory quinazolinone derivatives containing heterocyclic moieties by several methods and evaluates their in vitro anti-inflammatory, anti-oxidant, and biological activities. The chemical structures of the compounds synthesized were confirmed by spectral analysis, such as FT-IR, UV, GCMS, and 1H-NMR. The anti-inflammatory effect of these compounds was evaluated using the inhibition of denaturation method of bovine serum albumin (BSA) and the results have shown significant in vitro activity. The antioxidant activity was evaluated using nitric oxide with a hydroxyl radical scavenging assay, which showed a potential in radical scavenging due to the of electron donating substituent existence on substituted aldehydes. The antifungal and antimicrobial activity of the synthesized compounds against Fungi (C.albicans and A.niger), gram-positive (S.aureus and S.pyogenes) and gram-negative (E.coli and P.aeruginosa) have been studied. The results showed a high activity against gram negative bacteria (E.coli and P.aeragines) appeared for all compounds except for compound (1a) which showed a moderate activity against E. coli and weak against (P.aeragines). More studies are required to check confirm the antioxidant and biological activities of quinozalinone derivatives.

In this work, a novel solid phase microextraction fiber based sol-gel coating technology reinforced with carboxylated multiwall carbon nanotube have been prepared, developed, and optimized to determine tramadol in environmental water samples using gas chromatography-flame ionization detector. To reinforce sol-gel and increase in the extraction efficiency of tramadol, the sol-gel coated fiber was reinforced with carboxylated multiwall carbon nanotube. This solid phase microextraction fiber is disposable. Therefore, there is no risk of cross-contamination or carryover. Parameters that affect the extraction efficiency such as pH, extraction time, sample volume, volume of organic solvent, desorption time, and type of nanomaterials were optimized. Under optimized condition, linearity was observed in concentration ranges of 0.01-10 µgL-1 with correlation coefficient 0.996. Limit of detection (S/N=3) and limit of quantification (S/N=10) were 0.005 and 0.01 µg L-1, respectively. Relative standard deviations (n=5) was 3.13%. Using carboxylated multiwall carbon nanotubes for reinforcement of sol-gel coating leads to increasing extraction efficiency and decreasing the limit of detection. The relative recovery in the real sample (environmental water sample) was 85%. The proposed method can be used as a simple and sensitive method for detection of analgesic drugs such as tramadol in environmental water samples to control the environmental pollution.

A new Schiff base ligand bound to ionic liquid and crown ether was synthesized and complexed with Mn (III) metal. Manganese complex was used in the vicinity of oxone oxidant and the absence of an axial base in water-chloroform biphasic oxidation to oxidize different alkenes, the corresponding epoxides were obtained with 70-96% yields. The lowest efficiency is related to alkenes with electron-withdrawing groups.

In this study, new ethyl dioxoisoindolinyl cyclohexenone carboxylate derivatives have been synthesized via addition and cyclocondensation reactions when ethylacetoacetate added to chalcone compounds in a strong alkaline media. Ethylacetoacetate was added to chalcone compounds (D1-D10) in ethanol as solvent to produce cyclohexenone compounds (D11-D20), using sodium hydroxide as catalyst. The prepared compounds structures have been identified using the infrared spectroscopy (FT-IR) and some of them by 1H-NMR and 13C-NMR spectroscopy. The chalcones were prepared from our earliest published work. These new cyclohexenones have been applied as antibacterial agent towards Staphylococcus aureus, Staphylococcus epidermidis (gram-positive bacteria), and Escherichia coli (gram-negative bacteria). The results exhibited good antibacterial activity of the synthesized compounds against Staphylococcus aureus and Staphylococcus epidermidis at high concentrations (0.01 and 0.001) mg/mL compared to low concentration (0.001 mg/mL) because of high concentration effect.