scholarly journals The Determination of Caffeine Level of Wolaita Zone, Ethiopia Coffee Using UV-visible Spectrophotometer

2016 ◽  
Vol 4 (2) ◽  
pp. 59 ◽  
Author(s):  
Zewdu Tadesse Wondimkun
Keyword(s):  
Uv Visible ◽  
Caffeine Level

VALIDATED RP-HPLC AND UV-SPECTROSCOPY METHODS FOR THE ESTIMATION OF DAPAGLIFLOZIN IN BULK AND IN TABLETS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (03) ◽  
pp. 44-51
Author(s):  
B. Sabbagh ◽  
B. V. S. Lokesh ◽  
G. A. Akouwah ◽  
Keyword(s):  
Good Accuracy ◽  
Uv Spectroscopy ◽  
Linear Regression Analysis ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Uv Visible

Two methods were developed for the determination of dapagliflozin (DAPA) in pure form and in tablets. The procedure utilized was UV-Visible Spectroscopy and RP-HPLC with PDA detector to quantify DAPA in bulk and tablets. The sensitive linear range was identified for both methods within 0.5-5.0μg/mL. The linear regression analysis was identified for both methods with correlation coefficient(r)>0.99. The LOD and LOQ values were found to be 0.05 μg/mL and 0.5 μg/mL for the method by UV-Spectroscopy. The molar absorptivity (ε) was calculated as 1.27 X 105 L.mol-1cm-1. The RP-HPLC method produced LOD and LOQ values of 1.0 ng/mL and 0.5 μg/mL. Both methods were simple, precise, reproducible to quantify the amount of unknown in bulk as well as in tablets and estimated accurately within the range of 100.0±0.5%. Statistical analysis was performed on the data obtained. There was no significant difference between the developed and reported methods with p>0.05. Both methods can be applied for routine analysis of DAPA in bulk and tablets with good accuracy and precision.

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

2017 ◽  
Vol 9 (5) ◽  
pp. 102
Author(s):  
Sukhjinder Kaur ◽  
Taranjit Kaur ◽  
Gurdeep Kaur ◽  
Shivani Verma
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Pure Form ◽  
Nanostructured Lipid Carrier ◽  
Limit Of Quantification ◽  
Double Beam ◽  
Uv Visible ◽  
Development And Validation

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.

Free-base corroles: determination of deprotonation constants in non-aqueous media

2007 ◽  
Vol 11 (04) ◽  
pp. 269-276 ◽  
Author(s):  
Jing Shen ◽  
Zhongping Ou ◽  
Jianguo Shao ◽  
Michał Gałęzowski ◽  
Daniel T. Gryko ◽  
...  
Keyword(s):  
Equilibrium Constants ◽  
Aqueous Media ◽  
Free Base ◽  
Organic Base ◽  
Experimental Conditions ◽  
Spectral Changes ◽  
Base Analysis ◽  
Uv Visible ◽  
The Given

A series of free-base corroles with different electron-donating or electron-withdrawing substituents were reacted with piperidine, 4-aminopyridine, 2-methylimidazole, 2-aminopyridine or pyridine in PhCN and the UV-visible spectral changes monitored during conversion of ( Cor ) H 3 to [( Cor ) H 2]- as a function of the concentration and strength of the added organic base. Analysis of the UV-visible spectral changes as a function of the added base concentration enabled calculation of equilibrium constants ( logK ) for deprotonation of each corrole under the given experimental conditions. Relationships are examined between the experimentally measured logK values and previously published spectroscopic and structural properties of the compounds.

Design of a novel optical sensor for determination of trace amounts of copper by UV–visible spectrophotometry in real samples

2017 ◽  
Vol 32 (3) ◽  
pp. e4110
Author(s):  
Eslam Pourbasheer ◽  
Somayeh Morsali ◽  
Zhila Azari ◽  
Mohammad Ali Karimi ◽  
Mohammad Reza Ganjali
Keyword(s):  
Optical Sensor ◽  
Real Samples ◽  
Visible Spectrophotometry ◽  
Uv Visible

scholarly journals New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectroscopic Analysis ◽  
Palladium Complexes ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Enantiomerically Pure ◽  
One Step ◽  
Uv Visible ◽  
High Yields

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.

Preconcentration and Determination of Lead by Solidification of Floated Organic Drop Coupled with Nanodrop Spectrophotometry

2013 ◽  
Vol 829 ◽  
pp. 825-830 ◽  
Author(s):  
Ali Mazloomifar ◽  
Nafiseh Khatibi
Keyword(s):  
Sea Water ◽  
Chelating Agent ◽  
Limit Of Quantification ◽  
Liquid Phase Microextraction ◽  
Relative Standard ◽  
Preconcentration Factor ◽  
Uv Visible ◽  
Optimized Conditions ◽  
Sample Vial

The liquid-phase microextraction based on solidification of floating organic microdrop coupled with UV-visible spectrophotometer for preconcentration and determination of lead in the aqueous samples has been developed. In this technique, 20μL of 1-undecanol containing dithizone as the chelating agent (10-3mol L-1) was transferred to the water samples containing lead ions, and the solution was stirred for 25 min. The sample vial was cooled in an ice bath for 5 min. The solidified extract was transferred into a conical vial where it melted immediately, and then the organic phase was analyzed by Nanodrop spectrophotometer. Factors that influence the extraction and complex formation, such as pH, concentration of dithizone, extraction time, effect of ionic strenght, temperature and stirring rate were optimized. Under the optimized conditions, a preconcentration factor of 356, detection limit of 0.006 μgL-1, limit of quantification 0.018 μgL-1and a good relative standard deviation of 2.1% were obtained. The procedure was applied to sea water, mineral water and well water.

scholarly journals DEVELOPMENT AND VALIDATION OF UV-VISIBLE SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF DULOXETINE

2019 ◽  
pp. 27-31
Author(s):  
LIPSA SAMAL ◽  
AMARESH PRUSTY
Keyword(s):  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Solvent System ◽  
Spectrophotometric Analysis ◽  
Thiophene Derivative ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Uv Visible ◽  
Development And Validation

Objective: The aim of the present work was to develop and validate a simple UV spectroscopic method for the determination of duloxetine, which is a thiophene derivative and a selective neurotransmitter reuptake inhibitor for serotonin, norepinephrine, and to lesser degree dopamine. Methods: The UV Spectrophotometric analysis was performed using Shimadzu UV-1800 and Shimadzu UV-1700 spectrophotometer by using solvent system acetonitrile and water in the ratio of 8:2. Detection was performed at a wavelength of 290 nm. Method validation was carried out according to ICH Q2R1 guidelines by taking the parameters linearity, accuracy, precision, ruggedness, and robustness, LOD and LOQ. Results: The UV Spectrophotometric method was found linear in the range of 10-50 μg/ml. The method was rugged and robust with % relative standard deviation less than 2. The extraction recoveries were found to be higher than 99% in all experimental conditions. Conclusion: Based upon the performance characteristics, the proposed method was found accurate, precise and rapid and suitable for the determination of Duloxetine for routine analysis.

scholarly journals DETERMINATION OF THE ANTIOXIDANT ACTIVITY OF PRASMAN LEAF EXTRACTS (AYAPANA TRIPLINERVIS [VAHL]) AND THE TOTAL FLAVONOID AND PHENOL CONTENTS OF THE MOST ACTIVE EXTRACTS

2020 ◽  
pp. 107-111
Author(s):  
YUNITRIANTI ◽  
BERNA ELYA ◽  
ARIKADIA NOVIANI
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Total Flavonoid ◽  
Dpph Assay ◽  
Frap Assay ◽  
Methanol Extracts ◽  
Uv Visible ◽  
Antioxidant Effects

Objective: Prasman (Ayapana triplinervis [Vahl]) is a plant that can eliminate free radicals through its antioxidant effects. However, little research hasbeen conducted to explore the antioxidant activity of the plant.Methods: A. triplinervis (Vahl) leaves, which were determined by the Indonesian Institute of Sciences (LIPI) Bogor, were used in this study. Meanwhile,extraction was performed using n-hexane, ethyl acetate, and methanol as the solvents. Based on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay usinga UV–visible spectrophotometer and based on ferric reducing antioxidant power (FRAP) assay using a microplate reader.Results: Based on the DPPH assay using a UV–visible spectrophotometer, n-hexane, ethyl acetate, and methanol extracts with a final concentrationof 25 μg/mL inhibited DPPH radical production by 38.91, 51.03, and 54.06%, respectively. Using the percent inhibition, the IC50 for the ethyl acetateand methanol extracts were 28.71 and 23.472 μg/mL, respectively. Based on FRAP assay using a microplate reader, the n-hexane, ethyl acetate, andmethanol extracts had ferrous equivalent antioxidant capacity values of 460, 828.99, and 940.22 μmol/g, respectively. The methanol extract had thegreatest antioxidant activity. The ethyl acetate and methanol extracts at the initial concentrations contained total phenol levels of 12.06 and 42.11 mgGAE/g extract, respectively, as well as total flavonoid levels of 3.24 and 3.41 mg QE/g extract, respectively.Conclusion: Based on the determination of phenol and flavonoid levels, the methanol extract had the greatest antioxidant effects.

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