scholarly journals Highly Selective Derivative Spectrophotometric Determination of Vanadium(V) in Steels, Minerals and Soil Samples

2008 ◽  
Vol 7 (1) ◽  
pp. 13-25
Author(s):  
Anitha Varghese ◽  
A. M. A. Khadar
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Soil Samples ◽  
Trace Level ◽  
Acetic Acid Medium ◽  
First Order ◽  
First Derivative ◽  
Selective Derivative

A simple, selective and sensitive spectrophotometric method has been developed for the determination of trace amounts of Vanadium(V) in acetic acid medium using a newly synthesized reagent acetoacetanilide salicyloylhydrazone (AASH). The molar absorptivity and Sandell's sensitivity of the coloured species were found to be 1.20 x 104 L mol-1cm-1 and 4.2 ng cm-2 respectively. Beer's law is obeyed in the range 0.3 -3.0μ.g mL-1 of vanadium (V) at 405 nm. The stochiometry of the complex was found to be 1:1 (V (V): AASH). A highly selective first order derivative spectrophotometric method for the determination of vanadium is also reported. A calibration graph was derived by measuring first derivative amplitudes at 430 nm (trough depth). The metal ions which are normally associated with vanadium in minerals and alloys do not interfere. The developed procedure has been successfully applied for the trace level determination of vanadium in steels, minerals and soil samples.

First Order Derivative Spectrophotometric Determination of Thorium in Geological Samples Using Diacetylmonoxime p-hydroxybenzoylhydrazone

2012 ◽  
Vol 11 (1) ◽  
pp. 15-30
Author(s):  
Anitha Varghese ◽  
A M A Khadar
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Order Derivative ◽  
Geological Samples ◽  
Trace Level ◽  
First Order ◽  
Quantitation Limit ◽  
Triton X ◽  
Trace Level Determination

A simple, selective and sensitive spectrophotometric method has been developed for the determination of trace amounts of thorium using a newly synthesised reagent diacetylmonoximep-hydroxybenzoylhydrazone (DMPHBH) in the presence of Triton X-100. The molar absorptivity and Sandell’s sensitivity of the coloured species at pH 4.4 were found to be 4.20 x 104 L mol-1 cm-1 and 5.5 ng cm-2, respectively. Beer’s law is obeyed in the range 0.35 -3.8 mg mL-1 of thorium(IV) at 410 nm. The stoichiometry of the complex was found to be 1:2 (Th(IV): DMPHBH). A highly selective first order derivative spectrophotometric method for the determination of thorium in the presence of uranium is also reported. The detection limit and quantitation limit of first order derivative spectrophotometry were found to be 0.03 and 0.11 mg mL-1, respectively. The developed procedure has been successfully applied for the trace level determination of thorium in rock samples and synthetic mixtures.

Extractive Spectrophotometric Method for the Determination of Glibenclamide by Ion-Pair Complex in Pure Form and Pharmaceutical Formulation

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Pharmaceutical Formulation ◽  
Ratio Method ◽  
Colored Complex ◽  
Colored Product ◽  
Method Of Continuous Variation ◽  
Job's Method

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.

scholarly journals Simple Spectrophotometric Method for Determination of Paroxetine in Tablets Using 1,2-Naphthoquinone-4-Sulphonate as a Chromogenic Reagent

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Heba H. Abdine ◽  
Sawsan M. Amer ◽  
Lama I. Al-Rayes
Keyword(s):  
Spectrophotometric Method ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Official Method ◽  
Calibration Data ◽  
Pharmaceutical Tablets ◽  
Relative Standard ◽  
Label Claim ◽  
Colored Product

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak () at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 g . The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity () was L  1 . The limits of detection and quantitation were 0.3 and 0.8 g , respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was %. The results obtained by the proposed method were comparable with those obtained by the official method.

scholarly journals Nitroso-R-salt as a sensitive spectrophotometric reagent for the determination of paracetamol in pharmaceutical preparations

2009 ◽  
Vol 6 (3) ◽  
pp. 570-577
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Statistical Difference ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Subsequent Reaction ◽  
Experimental Conditions ◽  
Colored Complex ◽  
British Pharmacopoeia

Nitroso-R-salt is proposed as a sensitive spectrophotometric reagent for the determination of paracetamol in aqueous solution. The method is based on the reaction of paracetamol with iron(III) and subsequent reaction with nitroso-R-salt to yield a green colored complex with maximum absorption at 720 nm. Optimization of the experimental conditions was described. The calibration graph was linear in the concentration range of 0.1 – 2.0 ?g mL-1 paracetamol with a molar absorptivity of 6.9 × 104 L mol-1 cm-1. The method was successfully applied to the determination of paracetamol in pharmaceutical preparations without any interference from common excipients. The method has been statistically evaluated with British Pharmacopoeia method and no statistical difference between methods was found at the 95% confidence level.

scholarly journals Spectrophotometric method for the determination of Captopril in pharmaceutical formulations

2013 ◽  
Vol 10 (3) ◽  
pp. 965-970
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Maximum Absorption ◽  
Neutral Medium ◽  
Pharmaceutical Tablets ◽  
Colored Product ◽  
Sensitive Spectrophotometric Method

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of captopril in aqueous solution. The method is based on reaction of captopril with 2,3-dichloro 1,4- naphthoquinon(Dichlone) in neutral medium to form a stable yellow colored product which shows maximum absorption at 347 nm with molar absorptivity of 5.6 ×103 L.mole-1. cm-1. The proposed method is applied successfully for determination of captopril in commercial pharmaceutical tablets.

scholarly journals Spectrophotometric determination of phosphorus in coal and coal ash using bismuth-phosphomobybdate complex

2003 ◽  
Vol 68 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Randjel Mihajlovic ◽  
Natasa Ignjatovic ◽  
Marija Todorovic ◽  
Ivanka Holclajtner-Antunovic ◽  
Vesna Kaljevic
Keyword(s):  
Aqueous Solution ◽  
Ascorbic Acid ◽  
Acid Medium ◽  
Spectrophotometric Method ◽  
Methyl Ketone ◽  
Coal Ash ◽  
Molar Absorptivity ◽  
Stable Complex ◽  
Tolerance Limits

A modified spectrophotometric method using the bismuth phosphomolybdate complex for the determination of phosphorus in coal and coal ash is suggested. Bismuth together with phosphate and molybdate forms a very stable complex in acid medium which turns blue ("molibdenum blue") by reduction with ascorbic acid. The apparent molar absorptivity of PBiMo is 1.66x104 dm3 mol-1cm-1 at 720 nm and 2.10x104 dm3 mol-1cm-1 at 670 nm isobutyl methyl ketone (MIBK). Interference caused by the ions present are within the tolerance limits (?2 %). Beer?s law is obeyed in the for concentration range to 0.6 ?g/mL (aqueous solution) and to 1.2 ?g/mL P (MIBK). The sensitivity of the proposed method is 0.0078 ?g/mL (aqueous solution) and 0.0066 ?g/mL (MIBK).

scholarly journals Difference spectrophotometric method for the determination of Fluphenazine hydrochloride in tablets using peroxomonosulfate

2021 ◽  
Vol 9 (2) ◽  
pp. 64-71
Author(s):  
Mykola Blazheyevskiy ◽  
◽  
Valeriy Moroz ◽  
Olena Mozgova ◽  
◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Present Method ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Derivatizing Agent ◽  
Sensitive Method

The oxidative derivatization method using potassium hydrogenperoxomonosulfate for the indirect spectrophotometric determination of Fluphenazine hydrochloride is presented. Potassium hydrogenperoxomonosulfate is introduced as a derivatizing agent for Fluphenazine hydrochloride, yielding the sulfoxide. This reaction product was successfully used for the spectrophotometric determination of the Fluphenazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Fluphenazine hydrochloride in the concentration range of 0.2-30 µg mL-1. The molar absorptivity at 349 nm is 5.6×103 (dm3cm-1mol-1). The limit of quantification, LOQ (10S) is 0.24 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Fluphenazine hydrochloride in tablets 5.0 mg was demonstrated. The present method is precise, accurate and excipients did not interfere. RSD for Fluphenazine Hydrochloride 5.0 mg tablets was 1.37 %.

scholarly journals Development and validation of spectrophotometric method for phenylephrine hydrochloride estimation in nasal drops formulations

2008 ◽  
Vol 27 (2) ◽  
pp. 149 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Vladimir Banković
Keyword(s):  
Standard Deviation ◽  
Sodium Hydroxide ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Phenylephrine Hydrochloride ◽  
Relative Standard ◽  
Development And Validation

Simple, accurate and reproducible UV-spectrophotometric method was developed and validated for the estimation of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. Phenylephrine hydrochloride was estimated at 291 nm in 1 mol⋅dm-3 sodium hydroxide (pH 13.5). Beer’s law was obeyed in the concentration range of 10–100 μg⋅cm−3 (r2 = 0.9990) in the sodium hydroxide medium. The apparent molar absorptivity was found to be 1.63×103 dm3⋅mol−1⋅cm−1. The method was tested and validated for various parameters according to the ICH (International Conference on Harmonization) guidelines. The detection and quantitation limits were found to be 0.892 and 2.969 μg⋅cm−3, respectively. The proposed method was successfully applied for the determination of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %), while being simple, cheap and less time consuming, and hence can be suitably applied for the estimation of phenylephrine hydrochloride in different dosage forms.

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