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 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 Sensitive Spectrophotometric Methods for the Determination of Ascorbic Acid

2008 ◽  
Vol 5 (1) ◽  
pp. 10-15 ◽  
Author(s):  
H. D. Revanasiddappa ◽  
M. A. Veena
Keyword(s):  
Ascorbic Acid ◽  
Acid Medium ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Hydrochloric Acid Medium ◽  
Subsequent Determination ◽  
Sulphuric Acid Medium

Two simple and sensitive spectrophotometric methods (A and B) have been described for the determination of ascorbic acid. Method A is based on the oxidation of ascorbic acid (AA) by known excess of Se(IV) in hydrochloric acid medium and subsequent determination of unreacted Se(IV) by reacting it with iodide in the same acid medium to liberate iodine, which react with starch to form a stable blue coloured iodine-starch complex, which shows maximum absorbance at 590 nm. Method B is based on the oxidation of ascorbic acid (AA) by known excess of Cr(VI) in sulphuric acid medium and the determination of unreacted Cr(VI) with diphenyl carbazide (DPC) under the same acidic medium to produce a stable red-violet coloured species, which shows a maximum absorbance at 550 nm. The reacted oxidants (in methods A and B) correspond to the AA content. The apparent molar absorptivity values are found to be 1.627×104and 1.641×104L mol-1cm-1for methods A and B, respectively. The proposed methods are simple, sensitive and suitable for the routine analysis of AA in pharmaceutical formulations and in real samples.

scholarly journals DEVELOPMENT OF EXTRACTIVE SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF IRON (III) WITH SCHIFF BASE 2-[(2-HYDROXYPHENYLIMINO) METHYL]-4-NITROPHENOL

2016 ◽  
Vol 8 (4) ◽  
pp. 89 ◽  
Author(s):  
Datta B. Mandhare ◽  
Vasant D. Barhate
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Maximum Absorption ◽  
Ratio Method ◽  
Pharmaceutical Samples ◽  
Mole Ratio Method ◽  
Ph Range

Objective: A simple spectrophotometric method has been developed for the determination of Iron (III) by using Schiff base 2-[(2-hydroxyphenylimino) methyl]-4-nitrophenol [HPIMNP].Methods: HPIMNP extracts Fe (III) quantitatively (99.95%) into chloroform from an aqueous solution of pH range 4.0-6.0.Results: The chloroform extracts show maximum absorption at 510 nm (λ max). Beer’s Law is obeyed over the Fe (III) concentration range of 0.5 to 20.0 µg/ml. The Molar absorptivity and Sandell’s sensitivity for Fe–HPIMNP system is 5000 L mol ˉ1 cmˉ1 and 0.011 µg cmˉ2respectively. The composition of extracted species is found to be 1: 3 [Fe-HPIMNP] by Job’s continuous variation and Mole-ratio method. Interference by various ions has been studied.Conclusion: The proposed method is rapid, sensitive, reproducible and accurate and it has been satisfactory applied for the determination of Iron in Pharmaceutical Samples.

scholarly journals Solvent Extraction of Thorium Using 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Quang Hieu Tran ◽  
Van Tan Le ◽  
Van Cuong Nguyen
Keyword(s):  
Aqueous Solution ◽  
Solvent Extraction ◽  
Molar Absorptivity ◽  
Tolerance Limits ◽  
Acidic Aqueous Solution ◽  
Selective Method ◽  
Chloroform Layer ◽  
Effects Of Ph ◽  
Synthetic Solution

A rapid, sensitive, and selective method for determination of thorium based on the complex withortho-ester tetra-azophenylcalix[4]arene (TEAC) was described. In the presence of pH of 4–6, TEAC-Th(IV) complex is extracted from an acidic aqueous solution into chloroform layer. The absorbance intensity of complex was measured by UV-Vis spectrometer at 525 nm and the molar absorptivity was found to be 2.4 × 104. Beer’s law was obeyed in the range of 1.0 to 25 × 10−5 M thorium(IV). The effects of pH, TEAC concentration, and shaking time were also studied. The tolerance limits for several metal ions were calculated. The proposed method was applied to the determination of thorium in synthetic solution and in the monazite sand samples with good results.

scholarly journals Extractive Spectrophotometric Method for Determination of Molybdenum in Steels and Environmental Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Rameshwar Dass ◽  
Jitander K. Kapoor ◽  
Sunita Gambhir
Keyword(s):  
Ascorbic Acid ◽  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Environmental Samples ◽  
Room Temperature ◽  
Molar Absorptivity ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Improved Accuracy

An extractive spectrophotometric method has been developed for microdetermination of molybdenum. At room temperature Mo(VI) was reduced to Mo(V) in 2 M H2SO4using ascorbic acid as a reductant. The Mo(V) formed a yellow-coloured (1 : 2) complex with 6-chloro-3-hydroxy-2-(3′-hydroxyphenyl)-4-oxo-4H-1-benzopyran (CHHB). The complex was quantitatively extracted into toluene and absorbed maximum atλmax404 nm. Beer’s law was obeyed over the concentration range of 2.31 μg Mo ml−1with a molar absorptivity and Sandell's sensitivity of5.62×104 L mol−1 cm−1and 0.0016 μg Mo cm−2, respectively. The relative standard deviation was 0.0025 (in absorbance units) for 10 replicate determinations of 1 μg Mo ml−1. The method was free from the interference of large number of analytically important elements. Molybdenum has been determined satisfactorily in different technical, synthetic, and environmental samples with improved accuracy and precision.

scholarly journals Development of Extractive Spectrophotometric Determination of Rhodium (III) using Schiffs Base as An Analytical Reagent

2021 ◽  
pp. 1101-1105
Author(s):  
Mrs. Ritika Makhijani
Keyword(s):  
Aqueous Solution ◽  
Elemental Analysis ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Amyl Alcohol ◽  
Schiff’S Base ◽  
Analytical Reagent ◽  
Ph Range ◽  
Method Show

Rh (III) was determined by simple, sensitive & feasible spectrophotometric method by using analytical reagent N - (o - methoxy benzaldehyde) 2-aminophenol (NOMBAP) . Elemental analysis was used to characterize synthesized Schiff’s base NOMBAP. Rh (III) is extracted quantitatively (99.66%) by NOMBAP into carbon tetra chloride from an aqueous solution having pH range 5.1 – 5.9. An intense peak at 480 nm (λ max) was observed in the extract of n-amyl alcohol. Beer’s law is obeyed over the concentration range 1.0 – 10.0 µg/ml for Rh (III). The molar absorptivity and Sandel’s sensitivity for Rh - NOMBAP system is 8248.23 dm3 mole-1cm-1and 0.08332 μgcm-2 respectively. Mole Ratio & Job’s Continuous Variation and Method show that the extracted species has composition 1:3 (Rh-NOMBAP). Study has been done for interference by various ions. For determination of Rh (III) in alloy the proposed method has been used.

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.

Collaborative Study of the Spectrophotometric Determination of Procainamide Hydrochloride

1976 ◽  
Vol 59 (4) ◽  
pp. 807-810
Author(s):  
Jeffrey C Hamm
Keyword(s):  
Sodium Hydroxide ◽  
Acid Medium ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Dosage Forms ◽  
Standard Deviations

Abstract The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

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