Double Beam UV-VIS Spectrophotometer Research Articles

Photocatalytic degradation of chlorpyrifos and methylene blue using α-Bi2O3 nanoparticles fabricated by sol–gel method

Organic dyes and pesticides, i.e. methylene blue and chlorpyrifos are the most frequently used in the various fields in everyday life for the different purpose. The presence of organic dyes and pesticides within the aquatic environment causes serious problems to the both types ecosystems. The aim of this study, to evaluate the photocatalytic degradation of methylene blue and chlorpyrifos in aqueous solution using α-Bi2O3 nanoparticles (NPs). The α-Bi2O3 NPs were successfully synthesized by sol–gel method and characterized by XRD, SEM, TEM, EDX and FTIR techniques. Moreover, the photocatalytic degradation of methylene blue and chlorpyrifos was investigated by optimizing the various parameters like pH, an initial concentration of the solution, irradiation time and photocatalyst dose, etc. The photocatalytic efficiency of α-Bi2O3 NPs was measured using a UV–visible double beam spectrophotometer. The results show that the α-Bi2O3 NPs have an average crystallite size of 32.47 nm with a highly rough and porous surface area. The optimized condition for the photocatalytic degradation was obtained at pH = 2 and pH = 5, the initial concentration of solution 10 mg/L and irradiation time 90 min for methylene blue and chlorpyrifos respectively. Besides this, the kinetics of photocatalytic degradation were investigated and the results indicate that the photocatalytic degradation of methylene blue and chlorpyrifos follows the pseudo-first order kinetics.

Analysis Of Phosphorus And Potassium Levels In Organic Fertilizer In The Integrated Laboratory Of Jombang District Agriculture Office

Quantitative analysis in the integrated laboratory of Jombang District Agriculture Office has been done on two samples of organic fertilizer with phosphorus and potassium parameters, considering these two elements are macronutrients which have an important role in the growth and development of plants. Determination of phosphorus level has been done by ascorbic acid method using double beam UV-Visible spectrophotometer, while determination of potassium level has been done by flame photometric method. There are 2 samples code of organic fertilizer, 13/F/16 and 14/F/16. From the result of analysis, the phosphorus level as P2O5 in 13/F/16 sample is 0.275%, while in the 14/F/16 sample is 0.29%. The potassium level as K2O in 13/F/16 sample is 2.58%, while in the 14/F/16 sample is 2.67%. These results meet the requirements for compost quality standards based on SNI 19-7030-2004, because they exceed the minimum requirements, which are 0.10% for phosphorus level and 0.20% for potassium level.

Use of Augmented Reality in the Instruction of Analytical Instrumentation Design

Instruction on the design of analytical instrumentation is a critical component of the analytical chemistry curriculum. To simplify this process and enable students to directly see how the instruments that are in their own laboratory setting work, the use of augmented reality technology can be implemented. In this report, the HP Reveal platform was used to create digital overlays that are triggered when students view an analytical instrument through their smartphone camera. From here, further information on the components and operation of the instrument can be presented to students. To demonstrate this technology, various overlays were created for four analytical instruments commonly taught in second-year undergraduate analytical chemistry courses: flame atomic absorption spectrometer, gas chromatograph–mass spectrometer, liquid chromatograph, and double-beam UV–vis spectrophotometer.

Development of Validated Q-absorbance Ratio, Derivative Spectrophotometric and Stability indicating RP-HPLC methods for the simultaneous estimation of Losartan Potassium & Hydrochlorothiazide in Pharmaceutical Dosage Form and comparison of the results by ANOVA

Hypertension is estimated to cause 7.5 million deaths, leading to 12.8 % of the total of all deaths worldwide. In the recent years, the combination of Losartan Potassium and Hydrochlorothiazide has attained significant popularity in reducing the risk of heart diseases particularly in the patients with hypertension and ventricular hypertrophy. The literature survey revealed that there were several chromatographic and spectroscopic methods for the simultaneous estimation of the selected drugs but it was noted that there were no reported comparative studies of the developed methods. Hence the authors attempted to develop new validated Q- absorbance ratio, Derivative spectrophotometric and Stability indicating RP-HPLC methods for the simultaneous estimation of Losartan Potassium and Hydrochlorothiazide in pharmaceutical dosage form. The authors also propose to compare the results obtained by ANOVA. The two Spectrophotometric methods were carried out using an Agilent Cary 60 UV-Visible double beam Spectrophotometer. In Q-absorbance ratio method, samples were measured at two wavelengths, 230 nm (isoabsorptive point) and 225.5 nm (?max of Hydrochlorothiazide). In Derivative spectroscopy, analysis was performed by derivatizing the zero order spectrum to the corresponding second order spectrum. Stability indicating RP-HPLC method was performed using Eclipse XDB C18 column where the samples were analyzed using a mixture of Acetonitrile and Water in the ratio of 70:30 % v/v as mobile phase at a flow rate of 1 ml/min. The drugs were monitored at 230 nm. The retention times for Losartan Potassium and Hydrochlorothiazide were found to be 1.010 minutes and 1.387 minutes respectively. The proposed methods were validated as per ICH guidelines. The results obtained from the three developed methods were then compared by ANOVA which indicated that the proposed methods can successfully be used for the analysis of Losartan Potassium and Hydrochlorothiazide in bulk or in combined dosage forms.

New first derivative spectrophotometric methods for the estimation of Bumetanide in tablet dosage forms

First derivative spectrophotometric methods have been developed for the assay of Bumetanide using Shimadzu UV-1800 Model double beam UV-VIS spectrophotometer in reagents such as hydrochloric acid, phosphate buffer pH 3.6, phosphate buffer pH 2.0 and distilled water. Bumetanide has shown linearity 10-70 µg/ml in all the methods and the linear regression equations are found to be y = 0.0015x - 0.0013 (R² = 0.9993), y= 0.0007x - 0.0004 (R² = 0.9991), y = 0.0014x - 0.0015 (R² = 0.9993) and y = 0.0014x - 0.0015 (R² = 0.9995) in hydrochloric acid, phosphate buffer pH 3.6, phosphate buffer pH 2.0, and distilled water respectively. The methods are validated as per ICH guidelines and found to be precise, simple and accurate.

Quantification of Itopride Hydrochloride from tablet dosage form by visible Spectroscopy

The present study to describe the Quantification of Itopride Hydrochloride from tablet dosage form by visible spectroscopy by applying principle of colorimetric study. It involves the measurement of the amount of ultraviolet (190-380 nm) or visible (380-800nm) radiation absorbed by a substance in solution. The final optimised method carried out on double beam UV-visible spectrophotometer (Shimadzu, model 1800) having two matched quartz cells with 1 cm light path by using Bromothymol blue of concentration 0.5% w/v solution. Itopride Hydrochloride detection wavelength was set at 479.40nm The linearity was found to be in the range of 10-50µg/ml. This method for the quantitative determination of the drug by validation in accordance with the International Conference on Harmonization. The proposed method is economic, simple, sensitive, reproducible, and accurate and no interference is observed due to common excipients of tablet. The proposed method was successfully applied to determination of Itopride hydrochloride in pharmaceutical formulations.

Development and Validation of Analytical Method for Standardisation of Curcumin Using RP-HPLC Method in Prepared Extract

Objective: The main objective of present work is to develop and validate simple, precise and accurate analytical method for identification of curcumin using RP-HPLC method in prepared extract. Methods: Spectrophotometric determination was performed on a Perkin-Elmer UV-VIS Double Beam Spectrophotometer to know the maximum absorbance of the compounds. Chromatographic separation was achieved using merck C18 analytical column (5 µm, 250 mm x 4.6 mm, i.d). The optimized solvent system consisted of methanol, acetonitrile in the ratio of 30:70 v/v. The effluents were detected by means of UV detector at 415nm. The proposed method was validated in accordance with International Conference on Harmonisation (ICH) guidelines. Results: Linearity was observed at a concentration range of 2.5-15µg/ml with a regression equation of y = 77703x – 586.13 and correlation coefficient of 0.9993. The retention time was found to be at 1.72min by means of the proposed method. The method was validated according to ICH guidelines and was found to contain the %RSD values below 2% which shows that the method was precise, accurate and specific. Conclusion: The developed method was validated as per the ICH guidelines which show that the method is sensitive, simple, precise and accurate. Thus the method is applied for the identification of curcumin in prepared extracts.

Time-dependent scattering of incident light of various wavelengths in ferrofluids under external magnetic field

Ferrofluids can exhibit the anisotropic thermodynamic properties under magnetic fields. The dynamic optical properties of ferrofluids in the presence of magnetic fields are of particular interest due to their potential application as various optical devices. Although time-dependent light scattering by ferrofluids have been extensively studied, the effect of wavelength of incident light have been rarely considered. Here, for the first time, we investigated both the time- and wavelength-dependent light scattering in water based ferrofluids containing Fe3O4 nanoparticles under an external magnetic field. The field-induced response behavior of the prepared ferrofluid samples was determined and verified first by thermal conductivity measurement and numerical simulation. Double-beam UV–Vis spectrophotometer was employed to record the temporal evolution of transmitted intensity of incident light of various wavelengths passing through the ferrofluid sample and propagating parallel to the applied field. As expected, the light intensity decreases to a certain value right after the field is turned on due to the thermal fluctuation induced disorder inside the flexible particle chains. Then the light intensity further decreases with time until the appearance of a minimum at time τ0 followed by an inversed increase before finally reaches equilibrium at a particular time. More importantly, the characteristic inversion time τ0 was found to follow a power law increase with the wavelength of incident light (τ0∼λα, where α=2.07). A quantitative explanation for the wavelength dependence of characteristic time was proposed based on the finite-difference time-domain (FDTD) method. The simulation results are in good agreement with our experimental observations. The time-dependent light scattering in ferrofluids under different incident wavelengths was rationalized by considering both the coarsening process of the particle chains and the occurrence of resonance within the magnetic scatterers. Our finding should be of value for the development of various light-tunable optical devices.

DEVELOPMENT AND VALIDATION OF UV-SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF HYDROQUINONE IN BULK, MARKETED CREAM AND PREAPARED NLC FORMULATION

Objective: The aim of the present work was to develop a simple, rapid, accurate and economical UV-visible spectrophotometric method for the determination of hydroquinone (HQ) in its pure form, marketed formulation as well as in the prepared nanostructured lipid carrier (NLC) systems and to validate the developed method.Methods: HQ was estimated at UV maxima of 289.6 nm in pH 5.5 phosphate buffer using UV-Visible double beam spectrophotometer. Following the guidelines of the International Conference on Harmonization (ICH), the method was validated for various analytical parameters like linearity, precision, and accuracy robustness, ruggedness, limit of detection, quantification limit, and formulation analysis.Results: The obtained results of the analysis were validated statistically. Recovery studies were performed to confirm the accuracy of the proposed method. In the developed method, linearity over the concentration range of 5-40 μg/ml of HQ was observed with the correlation coefficient of 0.998 and found in good agreement with Beer Lambert’s law. The precision (intra-day and inter-day) of the method was found within official RCD limits (RSD<2%).Conclusion: The sensitivity of the method was assessed by determining the limit of detection and limit of quantification. It could be concluded from the results obtained that the purposed method for estimation of HQ in pure form, in the marketed ointment and in the prepared NLC-formulation was simple, rapid, accurate, precise and economical. It can be used successfully in the quality control of pharmaceutical formulations and for the routine laboratory analysis.

Estimation of Melanoidin concentration in palm oil mill effluent ponding system and its treatment using Calcium Lactate

Colour removal from wastewater is among the major challenge in water and wastewater treatment. Among others, melanoidin could be the source of colour in wastewater. In this study, the estimation of melanoidin concentration in conventional palm oil mill effluent (POME) ponding system was investigated. Melanoidin was analyzed by detecting its absorption using double beam UV-Vis spectrophotometer. For melanoidin, the maximum absorption is 330nm. From the analysis, the melanoidin concentration decrease from anaerobic pond 1 to anaerobic pond 3 and slightly increase in anaerobic pond 4 and aerobic pond 1. After that, the melanoidin concentration decreased from aerobic pond 1 to final discharge. It is estimated that the anaerobic pond 1 had the highest melanoidin concentration which was 87.3 mg/L. Finally, the effectiveness of melanoidin removal using a coagulation/flocculation process was also studied. Calcium lactate was used as a coagulant and low molecular weight anionic polyacrylamide was used as a coagulant aid. The jar test experiment was carried out by using 0.3g/L calcium lactate solution and dosage of anionic polyacrylamide was altered in order to find out the best melanoidin removal. Experiments carried out by using sedimentation time of 20 minutes showed that the highest percentage removal of melanoidin was 80.93% at the dosage of 0.3g/L of calcium lactate without any anionic polyacrylamide being added. This result concluded that the addition of anionic polyacrylamide as coagulant aids is not significant when compared to the use of calcium lactate only.

The substrate effect on Ge doped GaN thin films coated by thermionic vacuum arc

This study focuses on characterization and understanding of the substrate effect on Ge doped GaN thin films coated onto transparent substrates. The produced films were deposited onto unheated glass and unheated polyethylene terephthalate by using thermionic vacuum arc technique. Gallium nitride and germanium pellets were used in the thin film production. Reflectance, refractive index and thicknesses of Ge doped GaN thin films were measured by optical interferometer using Cauchy model for fitting. The transmittances were determined in the wavelength range between 200 and 1000 nm by using UV–Vis double beam spectrophotometer. The optical Tauc method was used to determine the band gap energies of produced thin films. Surface morphologies of produced thin films were characterized by atomic force microscopy and also field emission scanning electron microscopy. In conclusion, the substrate effect on the optical and morphological properties of the produced thin films was observed.

DEVELOPMENT AND VALIDATION OF SIMULTANEOUS EQUATION METHOD FOR SIMULTANEOUS ESTIMATION OF TELMISARTAN AND NIFEDIPINE IN SYNTHETIC MIXTURE

This method deals with the simultaneous determination of the Telmisartan and Nifedipine in the synthetic mixture . This method is simple, precis e, accurate and economical . The work was carried out on Shimadzu model 1800 ( Japan ) double beam UV visible spectrophotometer with spectral width of 2 nm, wavelength accuracy of 0 . 5 nm and a pair of 10 mm matched quartz cell was used to measure absorbance o f all the solutions . Distilled methanol was used as a solvent . The linearity r ange for both the drugs Telmisartan and Nifedipine wer e 1 - 18µg / ml and 2 - 20µg / ml . The T elmisartan has absorbance maxima at 297 . 2 nm and N ifedipine h as absorbance maxima at 235 . 5 n m in distilled methanol . The mean recovery was 100 . 7 ± 0 . 64 for T elmisartan and 100 . 3 ± 0 . 77 for N ifedipine respectively . The results of analysis have been validated statically and by recovery studies . This simple and precise method can be used for routine ana lysis of both the drugs in quality control laboratories .

Synthesis and Characterization of Uniform Spherical Nanoporous TiO2Aerogel Templated by Cellulose Alcohol-Gel with Enhanced Photocatalytic Activity

The spherical nanoporous TiO2aerogels were prepared by a simple ethanol-thermal method, using spherical cellulose alcohol-gel as the template. The morphology, crystalline structure, pore size, specific surface area, and the photocatalytic activity of obtained TiO2aerogel were separately characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2adsorption-desorption isotherms, and double beam UV-VIS spectrophotometer. The characteristics of TiO2aerogels presented uniform sphere shape, good internal structural morphology, high specific surface area (ranging from 111.88 to 149.95 m2/g), and good crystalline anatase phase. Moreover, methyl orange dye was used as the target pollutant to characterize the photocatalytic activities and the adsorption performance. The photocatalytic experiment shows that the obtained spherical TiO2aerogels had a higher degradation ratio of 92.9% on methyl orange dye compared with aspherical TiO2aerogels prepared from other concentrations of tetrabutyl orthotitanate (TBOT).

Synthesis and Investigation of Phenol Red Dye Doped Polymer Films

The optical properties of the pure polymer film and polymer films doped with Phenol Red dye at different concentrations were investigated. The films were prepared using the casting technique. Poly (methyl-methacrylate) (PMMA) polymer was doped with the Phenol Red dye dissolved in a mixture of chloroform and little quantity of methanol, used as suitable solvent for both the dye and the polymer. The spectral absorption measurements of these films were carried out at different dye concentrations using UV-Vis double-beam spectrophotometer in the wavelength range 300 - 800 nm. The optical parameters of the prepared Phenol Red dye doped polymer films, absorption coefficient (α), extinction coefficient (κ), refractive index (n), optical and electrical conductivities (σopt and σelect), and optical energy band gap (Eg), were determined. The results showed that the Phenol Red dye doped polymer film is a good candidate for photonic applications such as, solar cells, optical sensors, and other photonic devices.

Enhanced photocatalytic activity of supported CuO–ZnO semiconductors towards the photodegradation of mefenamic acid aqueous solution as a semi real sample

The elimination mefenamic acid (MA) as a pollutant from the aquatic environment using Hg lamp during a catalytic photodegradation process using supported ZnO–CuO onto clinoptilolite nanoparticles (NCP) was the aim of the study. Raw and supported clinoptilolite were characterized by FT-IR, XRD, DRS, TEM and SEM techniques. The changes of MA concentration determined by UV–vis double beam spectrophotometer at λmax 285nm and used for the calculation of its degradation extent. Better degradation efficiencies obtained for the supported the hybridized ZnO–CuO system onto NCP with respect to unsupported one and supported/unsupported ZnO and CuO. The degradation efficiencies are dependent to the experimental conditions and hence the parameters were optimized to reach the highest efficiencies.

Effects of intermittent atomization on the properties of Al-doped ZnO thin films deposited by aerosol-assisted chemical vapor deposition

Al-doped ZnO (AZO) thin films were prepared on glass substrates with different atomization interval times by aerosol-assisted chemical vapor deposition method. The structure, morphology, and optical and electrical properties were investigated by X-ray diffractometer, atomic force microscope, UV-vis double beam spectrophotometer and 4 point probe method. ZnO thin films exhibited strong growth orientation along the (002) plane and the crystalline was affected by the atomization interval time. All the films had high transmittance and the films with interval times of 2min and 4min had good haze values for the transparent conducting oxide silicon solar cell applications. The AZO thin film had the best optical and electrical properties when the atomization interval time was 4min. This is very important for the optoelectronic device applications. The surface morphology of AZO films depended on the atomization interval time.

Deposition of a Mo doped GaN thin film on glass substrate by thermionic vacuum arc (TVA)

Current research presents a new deposition method for GaN thin films that produces in a very short production time for GaN-based solid-state applications. A Mo doped GaN thin film on a glass substrate was produced by thermionic vacuum arc (TVA) technique. The TVA technique is a novel non-reactive plasma technique. The optical properties were determined by Filmetrics F20 interferometer and UV–Vis double beam spectrophotometer. The surface morphology was analyzed using field emission scanning electron microscopy and atomic force microscopy. The mean thickness value was measured as 100 nm by Filmetrics interferometer. The crystalline structure of the produced thin film has a Wurtzite crystal structure (004) as obtained by X-ray diffraction. Hardness value was determined as 14 GPa with the Oliver–Pharr method. The obtained properties are consistent with the values reported in related literature. The findings indicate that the TVA method provides advantages for optical and industrial applications.

A home-made system for IPCE measurement of standard and dye-sensitized solar cells.

A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

Influences of film thickness on the structural, electrical and optical properties of CuAlO2 thin films

CuAlO2 films with different thickness were prepared by the radio frequency magnetron sputtering technique. The structural, electrical and optical properties of CuAlO2 were studied by X-ray diffraction, atomic force microscope, UV–Vis double-beam spectrophotometer and Hall measurements. The results indicate that the single phase hexagonal CuAlO2 is formed and the average grain size of CuAlO2 films increases with increasing film thickness. The results also exhibit that the lowering of bandgap and the increase of electrical conductivity of CuAlO2 films with the increase of their thickness, which are attributed to the improvement of the grain size and the anisotropic electrical property. According to the electrical and optical properties, the biggest figure of merit is achieved for the CuAlO2 film with the appropriate thickness of 165nm.

Removal of hexavalent chromium from aqueous solutions using barks of Acacia albida and leaves of Euclea schimperi

Removal of hexavalent chromium ions (Cr(VI)) from aqueous solutions by adsorbents prepared from barks of Acacia albida of Fabaceae family and leaves of Euclea schimperi of Ebenaceae family has been studied by batch adsorption technique. Double-beam UV-visible spectrophotometer was used to monitor the concentration of Cr(VI). The influence of contact time, initial chromium ion concentration, pH and adsorbent dose on the efficiency of adsorption process was studied. Among the studied parameters, pH was found to be the most influential. At the optimum pH (pH 2), 98.47 and 97.39 % removal of Cr(VI) was achieved using the adsorbents prepared from barks of A. albida and leaves of E. schimperi, respectively. After determining the optimal conditions for maximum adsorp- tion, the applicability of the biosorbents was tested on real samples. The results indicate that these adsorbents can be employed as low-cost alternatives to commercial adsor- bents for the removal of Cr(VI) from effluents. Adsorption isotherms and kinetic parameters were also studied. The results showed that the adsorption of Cr(VI) by these adsorbents follow Langmuir adsorption isotherm. The kinetics of the adsorption process follows the pseudo-sec- ond-order kinetic model.