scholarly journals Spectrophotometric determination of metoclopramide hydrochloride in pharmaceutical tablets, by diazotization-coupling method with 1-naphthol as the coupling agent

2010 ◽  
Vol 7 (1) ◽  
pp. 704-712
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
British Pharmacopoeia ◽  
Pharmaceutical Tablets ◽  
Hydrochloric Acid Medium ◽  
Metoclopramide Hydrochloride ◽  
Sensitive Spectrophotometric Method

Simple, rapid and sensitive spectrophotometric method was proposed for the analysis of metoclopramide hydrochloride (MPH) in pure form as well as in pharmaceutical tablets. The method is based on the diazotization reaction of MPH with sodium nitrite in hydrochloric acid medium to form diazonium salt, which is coupled with 1-naphthol in sodium hydroxide medium to form azo dye, showing absorption maxima at 550 nm. Beer’s law is obeyed in the concentration range of 0.4 – 18 µg mL-1 of MPH with detection limit 0.5448 µg mL-1. The molar absorptivity and Sandell’s sensitivity are 3.4969 × 104 L mol-1 cm-1 and 0.0101 µg cm-2, respectively. The method was successfully applied to the determination of MPH in pharmaceutical tablets without any interference from common excipients used as additives in tablets. The results agree favorably with the official British Pharmacopoeia method.

scholarly journals Spectrophotometric Determination of Doxycycline Hyclate in Pure and Capsule using Diazotization Reaction

2017 ◽  
Vol 27 (5) ◽  
pp. 50 ◽  
Author(s):  
Ruba Fahmi Abbas ◽  
Ali Amer Wheeb ◽  
Ala'a Abdullwahid Jasim
Keyword(s):  
Detection Limit ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
Amine Group ◽  
Doxycycline Hyclate ◽  
Hydrochloric Acid Medium ◽  
Yellow Orange ◽  
Sensitive Spectrophotometric Method

A sensitive spectrophotometric method has been developed for the determination of Doxycycline hyclate (DCH) as pure and  capsule forms. This method is based on diazotization of primary amine group of benzocaine with sodium nitrite in hydrochloric acid medium; the formed diazonium salt is then reacted with DCH in sodium hydroxide medium, to form yellow – orange Azo dye. Beer's law is obeyed in the concentration rang 16-34mg. ml-1 at 480 nm with detection limit LOD and molar absorptivity Є were found to be 0.418 mg.ml-1 and 2.214× 10+4 L.mol-1.cm-1, respectively.

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 New Spectrophotometric Determination of Cefdinir by Batch Method and Cloud Point Extraction

2019 ◽  
Vol 30 (1) ◽  
pp. 85
Author(s):  
Omar Qusay Mezhir
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Cloud Point ◽  
Azo Dye ◽  
Cloud Point Extraction ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
Purple Colour ◽  
Beer's Law ◽  
Beer’S Law

In this study, new spectrophotometric methods were developed for estimation of cefdinir (CFD); the research consists of two methods. The first method depends on the conversion of function group amine in cefdinir to diazonium salt and then combined with the 2, 5-Dimethylphenol (2, 5-DMP) reagent in the alkaline medium. The formed azo dye has a purple colour with absorption intensity at λmax 510 nm. Concentration range was obeyed Beer's law at (1-50 μg / ml), correlation coefficient was 0.9998, molar absorptivity was 1.54 × 104 L.mol-1.cm-1 and the detection limit was 0.04 μg.ml-1. The second method is including cloud point extraction (CPE) of a trace amount of the formed azo dye in the first method followed by measuring with a UV-visible spectrophotometer. Concentration range that obeyed the Beer's law was (0.2-6 μg / ml), correlation coefficient was 0.9998, molar absorptivity was1.48×105 L.mol-1.cm-1, detection limit was 0.004 μg.ml-1, Pre-concentration factor was 25 and Distribution coefficient was 125.The proposed methods were applied and proved their compatibility for estimating of ingredient compound in pure samples and pharmaceuticals by comparing them with previous studies. Keyword: cefdinir, diazotization, cloud point extraction, 2, 5-Dimethylphenol.

scholarly journals Spectrophotometric Determination of Bromhexine Hydrochloride in Its Pharmaceutical Preparations by Diazotization and Coupling Method

2020 ◽  
pp. 2172-2181
Author(s):  
Saad Hasani Sultan ◽  
Zainab Walid Majed
Keyword(s):  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Standard Methods ◽  
Alkali Medium

A simple, fast, and sensitive spectrophotometric method was suggested for the determination of Bromhexine Hydrochloride (BHH) in its pharmaceutical formulations. The method depends on the diazotization of BHH by sodium nitrite in acidic medium to produce the corresponding diazonium salt. The latter is coupled with phloroglucinol reagent in alkali medium to form a yellow water soluble azo-dye which has a maximum absorption at 405 nm with a molar absorptivity of 2.7×104 l.mol-1.cm-1 and Sandellʼs sensitivity of 0.01517 µg.cm-1. Beerʼs low is obeyed within a concentration range of 0.25-15 µg.mL-1 of BHH. The LOD and LOQ values of the proposed method were 0.087 µg.mL-1 and 0.293 µg.ml-1, respectively. The proposed method was validated with standard methods and successfully applied to the determination of Bromhexine in its pharmaceutical formulations as tablets, syrup, and injections.

scholarly journals Indirect Spectrophotometric Determination of Chromium

1996 ◽  
Vol 79 (4) ◽  
pp. 989-994 ◽  
Author(s):  
N Balasubramanian ◽  
V Maheswari
Keyword(s):  
Alkaline Medium ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Pharmaceutical Preparations ◽  
Industrial Effluents ◽  
Molar Absorptivity ◽  
Chromium Vi ◽  
Alloy Steels ◽  
Ethylenediamine Dihydrochloride

Abstract A sensitive spectrophotometric method for determining trace amounts of chromium(VI) is described. In the presence of acetate buffer, chromium(VI) oxidizes hydroxylamine quantitatively to nitrite at pH 4.0 ± 0.5. The nitrite diazotizes p-nitroaniline to form a diazonium salt that, in acidic medium, couples with N-(1-naphthyl)ethylenediamine dihydrochloride to form an azo dye with a molar absorptivity of 4.1 x 104 L/mol-cm at 545 nm. The color is stable for 5 h, and the system obeys Beer's law in the range 0-8 μg chromium(VI) in a final volume of 10 mL. The detection limit of chromium(VI) is 0.6 μg. Chromium(lll) can be determined after it is oxidized with bromine water in alkaline medium to chromium(VT). Extraction of the azo dye in alkaline medium with methyl isobutyl ketone followed by addition of methanolic hydrochloric acid permitted determination of chromium(VI) down to 10 ng/mL. The method has been used to determine chromium in alloy steels, pharmaceutical preparations, and industrial effluents.

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad
Keyword(s):  
Drinking Water ◽  
Detection Limit ◽  
Complex Formation ◽  
Molar Absorptivity ◽  
Colorimetric Determination ◽  
Zirconium Complex ◽  
Reliable Determination ◽  
Percentage Recovery ◽  
Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

Determination of Unconjugated and Total N-Acetyl-p-aminophenol (NAPA) in Urine and Serum

1967 ◽  
Vol 13 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Karel P M Heirwegh ◽  
Johan Fevery
Keyword(s):  
Liver Disease ◽  
Acid Hydrolysis ◽  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Accurate Method ◽  
Total N ◽  
Hydrolysis Of ◽  
Urine And Serum

Abstract A sensitive and accurate method is described for the determination of N-acetyl-p-aminophenol (NAPA) and its metabolites in urine and serum. In strongly acidic medium, p-aminophenol (PAP) resulting from differential extraction and acid hydrolysis of total NAPA and unconjugated NAPA, is diazotized and the diazonium salt coupled with N-(1-naphthyl)ethylenediamine (NED) in the presence of ethanol. The blue azo dye formed is determined spectrophotometrically. Application to liver disease is briefly reported.

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 Spectrophotometric determination of nicradipine and isradipine in pharmaceutical formulations

2009 ◽  
Vol 15 (2) ◽  
pp. 69-76 ◽  
Author(s):  
S.M. Al-Ghannam ◽  
A.M. Al-Olyan
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Reaction Pathway ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Zinc Powder ◽  
Conditional Stability ◽  
Conditional Stability Constant

A sensitive spectrophotometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine and isradipine either in pure form or in pharmaceutical preparations. The method is based on the reduction of nicardipine and isradipine with zinc powder and calcium chloride followed by further reduction with sodium pentacyanoaminoferrate (II) to give violet and red products having the absorbance maximum at 546 and 539 nm with nicardipine and isradipine, respectively. Beer's law was obeyed over the concentration range 8.0-180 ?g/ml with the detection limit of 1.67 ?g/ml for nicardipine and 8.0-110 ?g/ml with the detection limit of 1.748 ?g/ml for isradipine. The analytical parameters and their effects on the reported methods were investigated. The molar absorptivity, quantization limit, standard deviation of intercept (Sa), standard deviation of slope (Sb) and standard deviation of the residuals (Sy/x) were calculated. The composition of the result compounds were found 1:1 for nicardipine and 1:2 for isradipine by Job's method and the conditional stability constant (Kf) and the free energy changes (?G) were calculated for compounds formed. The proposed method was applied successfully for the determination of nicardipine and isradipine in their dosage forms. The results obtained were in good agreement with those obtained using the reference or official methods. A proposal of the reaction pathway was presented.

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.

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