scholarly journals Batch and Flow-Injection Spectrophotometric Determination of Thymol Using Procaine Hydrochloride as a New Chromogenic Reagent

2012 ◽  
Vol 9 (2) ◽  
pp. 302-310 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Coupling Reaction ◽  
Water Soluble ◽  
Procaine Hydrochloride ◽  
Spectrophotometric Methods ◽  
Sample Throughput ◽  
Experimental Parameters ◽  
Colored Product ◽  
Mouth Wash ◽  
Versus Concentration

New, simple and sensitive batch and Flow-injecton spectrophotometric methods for the determination of Thymol in pure form and in mouth wash preparations have been proposed in this study. These methods were based on a diazotization and coupling reaction between Thymol and diazotized procaine HCl in alkaline medium to form an intense orange-red water-soluble dye that is stable and has a maximum absorption at 474 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 0.4-4.8 and 4-80 µg.ml-1 of Thymol, with detection limits of 0.072 and 1.807 µg.ml-1 of Thymol for batch and FIA methods respectively. The FIA procedure sample throughput was 80 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were successfully applied to the determination of Thymol in mouth wash preparations.

Simultaneous Spectrophotometric Determination of Salbutamol by Coupling with Diazotized 4-Aminobenzoic acid

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Hind Hadi ◽  
Gufran Salim
Keyword(s):  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Dosage Forms ◽  
Water Soluble ◽  
Trace Determination ◽  
Aminobenzoic Acid ◽  
Optimum Conditions ◽  
Colored Product ◽  
Versus Concentration

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.

scholarly journals Batch and Flow-Injection Spectrophotometric Determination of Procaine HCl in Pharmaceutical Preparations Via Using Diazotization and Coupling Reaction

2012 ◽  
Vol 9 (3) ◽  
pp. 521-531
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Injection ◽  
Diazonium Salt ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Standard Addition ◽  
Water Soluble ◽  
Spectrophotometric Methods ◽  
Colored Product ◽  
Average Sample

Simple and sensitive batch and Flow-injection spectrophotometric methods for the determination of Procaine HCl in pure form and in injections were proposed. These methods were based on a diazotization reaction of procaine HCl with sodium nitrite and hydrochloric acid to form diazonium salt, which is coupled with chromatropic acid in alkaline medium to form an intense pink water-soluble dye that is stable and has a maximum absorption at 508 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 1-40 and 5-400 µg.ml-1 of Procaine HCl, with detection limits of 0.874 and 3.75 µg.ml-1 of Procaine HCl for batch and FIA methods respectively. The FIA average sample throughput was 70 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were applied satisfactorily for the determination of Procaine HCl in an injections samples using the standard addition method.

scholarly journals SYNTHESIS OF NEW SUBSTITUTED PROCAINE HYDROCHLORIDE COMPOUNDS AND THEIR USE IN SPECTROPHOTOMETRIC DETERMINATION OF TETRACYCLINE HYDROCHLORIDE THROUGH DIAZOTIZATION-COUPLING REACTIONS

2021 ◽  
Vol 18 (39) ◽  
pp. 14-32
Author(s):  
Hind Sadiq Al-WARD ◽  
Mouayed Qassssim AL-ABACHI ◽  
Mohammed Rifaat AHMED
Keyword(s):  
Stability Constant ◽  
Thermodynamic Parameters ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Procaine Hydrochloride ◽  
Effect Of Temperature ◽  
Basic Medium ◽  
Fast Method ◽  
The Stability

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.

Green methods for the determination of nitrite in water samples based on a novel diazo coupling reaction

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Safwan M. Fraihat
Keyword(s):  
Water Samples ◽  
Acidic Medium ◽  
Coupling Reaction ◽  
Spectrophotometric Methods ◽  
New Methods ◽  
Diazo Coupling ◽  
Colored Product ◽  
Diazo Coupling Reaction

AbstractGreen, sensitive and selective spectrophotometric methods were developed for the determination of nitrite in water samples. The methods (A, B and C) are based on the reduction of 5-nitroimidazoles; metronidazole (MTL), secnidazole (SCL) and tinidazole (TNL), respectively, followed by diazotization using nitrite in acidic medium, then coupling with pyrogallol (PG). The amount of nitrite was determined by measuring the absorbance of the colored product at 385 nm. The new methods were linear in the ranges of 2.5–30 μgml

scholarly journals Optimization and Validation of Quantitative Spectrophotometric Methods for the Determination of Alfuzosin in Pharmaceutical Formulations

2007 ◽  
Vol 4 (3) ◽  
pp. 397-407 ◽  
Author(s):  
M. Vamsi Krishna ◽  
D. Gowri Sankar
Keyword(s):  
Room Temperature ◽  
Pharmaceutical Formulations ◽  
Good Precision ◽  
Spectrophotometric Methods ◽  
Experimental Parameters ◽  
Beer's Law ◽  
Colored Product ◽  
Beer’S Law ◽  
Control Application

Three accurate, simple and precise spectrophotometric methods for the determination of alfuzosin hydrochloride in bulk drugs and tablets are developed. The first method is based on the reaction of alfuzosin with ninhydrin reagent inN, N'-dimethylformamide medium (DMF) producing a colored product which absorbs maximally at 575 nm. Beer’s law is obeyed in the concentration range 12.5-62.5 µg/mL of alfuzosin. The second method is based on the reaction of drug with ascorbic acid in DMF medium resulting in the formation of a colored product, which absorbs maximally at 530 nm. Beer’s law is obeyed in the concentration 10-50 µg/mL of alfuzosin. The third method is based on the reaction of alfuzosin withp-benzoquinone (PBQ) to form a colored product with λmax at 400 nm. The products of the reaction were stable for 2 h at room temperature. The optimum experimental parameters for the reactions have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods could be used for the determination of alfuzosin in pharmaceutical formulations. The procedures were rapid, simple and suitable for quality control application.

scholarly journals Novel Spectrophotometric Methods for the Determination of Selegiline Hydrochloride in Bulk and Its Pharmaceutical Preparation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Kumble Divya ◽  
Badiadka Narayana
Keyword(s):  
Spectrophotometric Method ◽  
Pharmaceutical Preparation ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Colored Product ◽  
Optimum Reaction ◽  
Optimum Reaction Condition

A simple and highly selective spectrophotometric method has been developed for the determination of selegiline hydrochloride in bulk and formulations. Method A is based on the oxidation of 3-methyl-2-benzothiazolinone hydrazone in the presence of ceric ammonium sulphate, followed by its coupling reaction with drug to form a colored product having λmax of 629 nm. Method B is based on the coupling reaction of drug with 4-aminoantipyrine to give a new ligand that reacts with copper(II) to give intense bluish red colored chelate which is measured at 539 nm. Beer’s law is obeyed in the range of 10.00–85.00 μg mL−1 with molar absorptivity of 0.98×104 for method A and 20.00–120.00 μg mL−1 with molar absorptivity of 0.94×104 for method B. The optimum reaction condition and the analytical parameters are evaluated. The results obtained indicate that the methods are free from interference of the ingredients; thus they are successfully applied to pharmaceutical formulations.

scholarly journals Spectrofluorimetric and Spectrophotometric Determination of Gliclazide in Pharmaceuticals by Derivatization with 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole

2003 ◽  
Vol 86 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Nahed El-Enany
Keyword(s):  
Reaction Pathway ◽  
Biological Fluids ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Signal To Noise ◽  
Yellow Fluorescence ◽  
Spectrophotometric Methods ◽  
Experimental Parameters ◽  
Good Agreement

Abstract Accurate, sensitive, and simple spectrophotometric and spectrofluorimetric methods were developed for the determination of gliclazide in pharmaceutical formulations and biological fluids. Both methods are based on a coupling reaction between gliclazide and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in borate buffer, pH 7.8, in which a yellow reaction product that can be measured spectrophotometrically at 400 nm was developed. The same product exhibited a yellow fluorescence at 470 nm upon excitation at 400 nm. The absorbance–concentration plot was rectilinear over the range of 2–20 μg/mL with minimum detectability [signal-to-noise (S/N) ratio = 2] of 0.2 μg/mL (6.18 × 10−7 M); the fluorescence–concentration plot was rectilinear over the range of 0.2–2.5 μg/mL with minimum detectability (S/N = 2) of 0.02 μg/mL (6.18 × 10−8M). The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. Both methods were successfully applied to the analysis of commercial tablets. The results were in good agreement with those obtained with the official and reference spectrophotometric methods. A proposal of the reaction pathway was presented.

scholarly journals Spectrophotometric Methods for the Assay of Pyrilamine Maleate Using Chromogenic Reagents

2010 ◽  
Vol 7 (4) ◽  
pp. 1507-1513 ◽  
Author(s):  
V. Annapurna ◽  
G. Jyothi ◽  
V. Nagalakshmi ◽  
B. B. V. Sailaja
Keyword(s):  
Charge Transfer ◽  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Method Of Least Squares ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Charge Transfer Complexation

Simple, accurate and reproducible UV spectrophotometric methods were established for the assay of pyrilamine maleate (PYRA) based on the formation of oxidative coupling and precipitation, charge transfer complexation products. Method A includes the oxidative coupling reaction of PYRA with 3-methyl-2-benzathiazolinone hydrazone (MBTH) in presence of Ce(IV). The formation of oxidative coupling product with 4-amino phenazone (4-AP) in presence of K3Fe(CN)6is incorporated in method B. Precipitation/charge transfer complex formation of the PYRA with tannic acid (TA)/Metol-Cr(VI) in method C were proposed. The optical characteristics such as Beers law limits, molar absorptivity and Sandell’s sensitivity for the methods (A-C) are given. Regression analysis using the method of least squares was made to evaluate the slope (b), intercept (a) and correlation coefficient (r) and standard error of estimation (Se) for each system. Determination of pyrilamine in bulk form and in pharmaceutical formulations were also incorporated.

Analytic Methods for Bilirubin in Blood Plasma

1961 ◽  
Vol 7 (6) ◽  
pp. 603-625 ◽  
Author(s):  
Derek Watson
Keyword(s):  
Blood Plasma ◽  
Critical Evaluation ◽  
Coupling Reaction ◽  
Spectrophotometric Methods ◽  
Analytic Methods ◽  
Diazo Coupling ◽  
Diazo Coupling Reaction ◽  
In Blood Plasma

Abstract A critical evaluation of existing colorimetric and spectrophotometric methods for the determination of bilirubin in blood plasma is presented. The stoichiometric equivalences of the reagents used in the diazo coupling reaction are re-evaluated. The elimination of turbidity is discussed, as well as methods using diazo-coupling promoters. Recommendations are made concerning the preservation of specimens to prevent oxidation and procedures that give maximal specificity for the type of bilirubin pigment being assayed.

scholarly journals Use of N, N-diethyl-p-phenylenediamine sulphate for the spectrophotometric determination of some phenolic and amine drugs

2010 ◽  
Vol 60 (2) ◽  
pp. 217-227 ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Ashwinee Shrestha ◽  
Anantharaman Shivakumar ◽  
Avinash Gowda
Keyword(s):  
Spectrophotometric Determination ◽  
Correlation Coefficients ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Variable Parameters ◽  
Spectrophotometric Methods ◽  
Linear Relationships ◽  
Colored Product ◽  
And Performance

Use ofN, N-diethyl-p-phenylenediamine sulphate for the spectrophotometric determination of some phenolic and amine drugsSpectrophotometric methods are proposed for the determination of drugs containing a phenol group [salbutamol sulphate (SLB), ritodrine hydrochloride (RTD), isoxsuprine hydrochloride (IXP)] and drugs containing an aromatic amine group [dapsone hydrochloride (DAP), sulfamethoxazole (SFM), and sulfadiazine (SFD)] in pharmaceutical dosage forms. The methods are based on coupling ofN, N-diethyl-p-phenylenediamine sulphate with the drugs in the presence of KIO4to give a green colored product (λmaxat 670 nm) and a red colored product (λmaxat 550 nm), respectively. Linear relationships with good correlation coefficients (0.9986-0.9996) were found between absorbance and the corresponding concentration of drugs in the range 1-7, 2-22, 1-17, 1.5-12, 2-25, and 2-21 μg mL-1for SLB, RTD, IXP, DAP, SFM and SFD, respectively. Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. The RSD of intra-day and inter-day studies was in the range of 0.2-1.0 and 0.4-1.0%, respectively. No interference was observed from common pharmaceutical adjuvants. The reliability and performance of the proposed methods was validated statistically; the percentage recovery ranged from 99.5 ± 0.1 to 99.9 ± 0.3%. Limits of detection were 0.14, 0.21, 0.51, 0.44, 0.33 and 0.37 μg mL-1for SLB, RTD, IXP, DAP, SFM, and SFD, respectively.

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