This proposed analytical method by RP- HPLC- Uv/ Vis for simultaneous separation and determination of six antioxidants naturally present in Hibiscus sabdraffia calyces was highly convenient for evaluation the level concentration of the compounds under study. The obtained results show also, that the Iraqi Hibiscus Sabdraffia calyces are rich in these compounds and can be used usefully for human consumption.
Abstract: Biphasic oily/water nanoemulsions have been proposed as delivery systems for the intranasal administration of curcumin (CUR) and quercetin (QU), due to their high drug entrapment efficiency, the possibility of simultaneous drug administration and protection of the encapsulated compounds from the degradation. To better understand the physicochemical and biological performance of the selected formulation simultaneously co-encapsulating CUR and QU, a stability test of the compounds mixture was firstly carried out using X-ray powder diffraction and thermal analyses, such as differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). The determination and quantification of the encapsulated active compounds was then required being an essential tool for the development of innovative nanomedicines. Thus, a new HPLC–UV/Vismethod for the simultaneous determination of CUR and QU in the nanoemulsions and their evaluation in stability studies in simulated biological fluids was developed and validated. The X-ray diffraction analyses demonstrated that no interaction between the mixture of active ingredients, if any, is strong enough to take place in the solid state. Moreover, the thermal analysis demonstrated that the CUR and QU are stable in the nanoemulsion production temperature range. The proposed analytical method for the simultaneous quantification of the two actives was selective and linear for both compounds in the range of 0.5 – 12.5 µ g/mL (R 2 > 0.9997), precise (RSD below 3%), robust and
Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vismethod. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R 2 ) is
To investigate effect of other organic acids on measurements, standard addition method was carried out. It was observed that lactic acid ( 2 mg/ mL), propanoic acid (1 mg/ mL), valeric acid ( 2 mg/ mL), fumaric acid( 2mg/ mL), and benzoic acid( 2 mg/ mL) did not affect the measurement of the acids under study and showed a different retention time.
These proposed methods were found to be simple, precise, accurate and sensitive.high percentage recover showed that the method was free from interference of excipients used in the formulation. Values LOD and LOQ showed that the proposed method was sensitive enough to analyse the drug in bulk as well as in it’s pharmaceutical formulation. Hence the proposed method renders suitable for routine analysis in quality control laboratory.
The electron spectrum of ligand and complexes in DMSO solution was measured between 200-1100 nm at room temperature. The UV-Visible spectra of free ligand include two absorption bands at wavelength 262 nm and 325 nm. The first transmission due to transition electron to π-π⃰ (aromatic ring) and the second transition due to transmission electron n-π⃰ (azomethene group) respectively
Figure 3 shows the chromatogram of the crude extract of Achillea fragrantisimma at 350 nm with main peak eluted at 44.8 min. and other 11 minor compounds showed a maximum absorption at this wavelength. The eluted compounds were detected in the range of 21-49 min. indicating polar and nonpolar compounds combination. The UV-Vis ranges of these compounds were in the range of 210-350 nm.
cost fabrication process for high-quality ZnO. Moreover, we reported the low-temperature synthesis of dumbbell- like ZnO, which synthesized at ambient pressure without any substrates or additives. The morphology, structure, and properties of the obtained ZnO were examined; the effects of the reactant concentration and reaction time on the size and shapes of the ZnO products were analyzed, and the possible growth mechanism of the ZnO microstructure was discussed. Furthermore, the room temperature UV–vis absorption and photo- luminescence (PL) spectrum of the obtained products were also investigated.
Nanoparticles (NPs) are defined as having one dimension 100nm or less in size and due to their large surface area they tend to react differently than larger particles of the same composition, allowing them to be utilized in novel applications . Among all nanomaterials, silver nanoparticles (AgNPs) are unique as they are used in vast arrays of applications including medicine, food and consumer products . Synthesis of such variety of AgNPs is possible by thermal decomposition , laser ablation , ultrasound  and aqueous chemical reduction method . In order to minimise the risk of environmental hazards and to ensure economic sustainability by reducing production costs, there is a growing need to develop eco-friendly protocols for the nanoparticles synthesis employing green chemistry approaches using cheaply available, renewable natural resources . One of them is synthesis of nanoparticles by biological process which implemented to develop safe, cost- effective and environmentally friendly technologies . Very recently green silver nanoparticles have been synthesized using various natural products like green tea (Camellia sinensis) , neem (Azadirachta indica) leaf broth ,
Extraction method by maceration was used because it was relatively simple and did not use heat. Heat treatment could degrade the anthocyanin pigment and formed colourless chalcone. Maceration process was done in dark bottles because anthocyanin compounds were very easily oxidized by light. In addition, the results of maceration should be stored in a refrigerator at a certain temperature 4°C because of its vulnerability caused by the heat. The solvent was ethanol that was acidified with acetic acid until pH 1. Ethanol was used as solvent because of its polarity and less toxic than methanol so it can be applied in food stuff. The purpose of using organic acids such as acetic acid, citric acid or tartaric acid as acidifier was to prevent any damage to the anthocyanin because of hydrolysis of glycoside bond and acylation of anthocyanin.
Abstract. We present the MPI-Mainz UV / VIS Spectral Atlas of Gaseous Molecules, which is a large col- lection of absorption cross sections and quantum yields in the ultraviolet and visible (UV / VIS) wavelength region for gaseous molecules and radicals primarily of atmospheric interest. The data files contain results of individual measurements, covering research of almost a whole century. To compare and visualize the data sets, multicoloured graphical representations have been created. The MPI-Mainz UV / VIS Spectral Atlas is avail- able on the Internet at http: // www.uv-vis-spectral-atlas-mainz.org. It now appears with improved browse and search options, based on new database software. In addition to the Web pages, which are continuously updated, a frozen version of the data is available under the doi:10.5281 / zenodo.6951.
3) Dielectric Studies: Dielectric measurements were carried out using the parallel plate capacitor method as a function of frequency. Dielectric measurements show that dielectric constant is inversely proportional to frequency. Dielectric loss with high frequency indicates crystal has good optical quality and such material has potential applications. The fluctuation in dielectric constant attributes the change in space charge contributions. At low frequency, the value of dielectric constant is low [18-19].
Hemiacetals being unstable compounds are difficult to isolate and it is difficult to establish their structure and spectroscopic properties by experiment. IR and NMR experimental data are available in the literature only for the hemiacetal 1-methoxy ethanol in a reaction mixture. The objective of the present work is to investigate how the methods based on density functional theory (DFT) and its time dependant version (TDDFT) can predict structural and spectroscopic properties of this unstable compound. Geometry optimization and frequency calculations have been carried out by DFT method at 6-31+G(d) and 6-31++G(d,p) levels. The UV-Vis spectra in a number of solvents have been calculated by the TDDFT method under the polarizable continuum model and the variation of the calculated UV- vis absorption peak with two solvent polarity indices (namely, E T (30) and Z-values) has been studied in these solvents; electronic transition energies at the λ max values in the theoretically calculated spectra increase with solvent polarity. The calculated infrared absorption bands and NMR chemical shifts ( 1 H
In simultaneous estimation method two wavelengths were used for analysis of drugs i.e. lambda max of paracetamol, 247nm and λmax of diclofenac, 280nm. After optimization of the method, process was validated statistically. The %RSD was found to be 1.632 shows that the method was accurate and precise.% purity were found to be104% for diclofenac and 110% for paracetamol which were within the permissiblelimit. From the beers law limit it concluded that paracetamol follows the range 2-12 µg/ml and diclofenac 2-40 µg/ml.The all statistical results shows thatmethod was genuine, precise, simpleand sensitive.
The main objective of current study is to develop and validate RP-HPLC, simple, precise, accurate and specific chromatographic method for the determination of atazanavir and degradation products are characterized by LC-MS/MS in tablets. A high performance liquid chromatography instrument and Hypersil BDS, 150 x 4.6 mm, 5 were used for determination of atazanavir. Mobile phase as a acetonitrile and buffer in the ratio of 1:1V/V .The flow rate of 1.0mL/min was set with isocratic, the temperature of column compartment maintained at 30°C and Ultra violet detection done at 248nm wavelength. The atazanavir eluted at 3 minutes and then run time was set as about 10 minutes. The correlation coefficient (≥ 0.999) shows the linearity of response against concentration over the range of 20 to 150%. The observed result shows that the method is rapid, precise, accurate and simple. The method was validated as per ICH guidelines.
The fluorescence and synchronous fluorescence spectra of proteins were recorded on a FL-4500 Spectrofluori- meter equipped with a 1.0 cm quartz cell. The CD spec- tra of proteins were recorded on a J-810 Circular Dichroism Spectrometer (Jasco, Japan). UV-1101 spec- trophotometer (Shimadzu, Japan), H-7000 transmission electron microscopy (Hitachi, Japan) and BI-200SM/BI- 9000 laser light scattering system (Brookhaven, USA) were used to characterize the C 60 dispersion. All the
ZnO nano-needles have been synthesized successfully on zinc substrate with the zinc-air cell method at room temperature. The effect of annealing temperature on the structure, morphology and optical properties of ZnO nano-needles were investigated using X-ray diffraction (XRD), Field Emission Scanning electron microscopy (FE-SEM) and ultraviolet-visible spectrometry (UV-Vis) techniques. XRD measurements indicated the presence of ZnO nano-needles with a hexagonal wurtzite structure and no external impurities. As the annealing temperature was increased from 400 o C to 600 o C the particle size increased and the nano-needles became more orientated with average height between 538.1 nm to 1195 nm. The UV-Vis measurements showed a slight decrease in absorbance and the absorption edge shifted slightly to lower energy. The apparent increase in the band gap energy from 3.29 to 3.30eV over the 400-600 o C temperature range is a variation of within 2% in the range, and cannot reliably be attributed to adverse effects such as defect formation at the high temperatures since it is within the measurement uncertainty. The nano-needles exhibit strong absorption peaks, which decrease with annealing temperature, in the wavelength range of ~360nm to 380nm. The nano- structures also exhibited increased crystallization strength. The absence of impurities after annealing was confirmed using energy dispersive spectroscopy
characterized using XRD, UV-Spectrophotometer and Two probe methods. The XRD pattern shows nano crystalline phase with cubic and hexagonal structure. Doped film shows the broadening peaks in XRD spectra. Scherrer formula gives particle size around 9.3nm.particle size decreasing on doping. For undoped CdZnS thin film, Optical band gap of comes out to be 2.5 eV, whereas band gap for rare earth doped CdZnS thin film was 2.4 eV, and 2.42 eV, respectively. Thus doping decreases the band gap. Photocurrent show linear increase with applied voltage. Moreover photocurrent is larger than the dark current for the same voltage .
The field of nanotechnology is the most active area of research in modern materials science. Though there are many chemical as well as physical methods, green synthesis of nanomaterials is the most emerging method of synthesis. We report the synthesis of antibacterial Silver nanoparticles (AgNPs) using flower of medicinal herb, Aerva lanata. The synthesized AgNPs have been characterized by UV-Vis spectroscopy, FT-IR, transmission electron microscopy (TEM) and Cyclic Voltammetry(CV). The mean particle of synthesized NPs was found to be 43.5 nm, as confirmed by TEM. FTIR analysis revealed that the AgNPs were stabilized by proteins, polyphenols and other aromatic compounds present in the extract. Such AgNPs stabilized by Aerva lanata flower extract were found to have enhanced antimicrobial activity against well-known pathogenic strains, namely E.Coli, Staphylococus aureus, Bascillus cereus and Pseudomonas aeruginosa.
Repeatability of the method expresses the precision under the same operating conditions over a short interval of time . The mean value of the concentration of ciprofloxacin hydrochloride in CB-12 combined ear drops was 0.15492 g/50 mL. Intermediate precision expresses within- laboratories variations, and in the present study accounted for different days . The mean value of the concentration of ciprofloxacin hydrochloride in the pharmaceutical dosage form for the intermediate precision study was 0.15493 g/50 mL.