Redox-Reaction Products Of 4-Sulfo-2-(4'-Sulfonaphthalene-1'-Azo) Naphthol-1 With Ce(IV) - New Analytical Forms For Its Quantitative Determination

2018 ◽  
pp. 167-176
Author(s):  
A.N. Chebotarev ◽  
I.S. Efimova ◽  
E.V. Raboshvil ◽  
E.M. Rakhlitskaya
Keyword(s):  
Lower Layer ◽  
Pharmaceutical Preparations ◽  
Self Organization ◽  
Blue Color ◽  
Reaction Products ◽  
Standard Samples ◽  
Volumetric Determination ◽  
Redox Interaction ◽  
Destructive Oxidation

The results of redox interaction of Ce (IV) with 4-sulfo-2-(4’-sulfonaphthalene-1’-azo) naphthol-1 (carmosine- KAN) in aqueous solutions (pH 1.75) have been presented. The destructive oxidation of CAS into two fragments (2-nitroso-4-sulfonaphthol-1 (L1) and 1-nitroso-4-sulfonaphthalene (L2)) is accampanied by reduction of Ce(IV) to Ce(III). It was found that an increase in the Ce(III) -L1 -L2 system acidity to pH ~ 11 leads to formation of the [Ce(III)(ОН)2·L1·2Н2О] complex. After acetonitrile is introduced to [Ce(III)(ОН)2·L1 ·2Н2О] – L2 system (up to 40 % by volume) self-organization of products involving CH3CN is observed. The resulting water-acetonitrile system becomes turbid, and after ~10 min phase separation is observed. Phase I contains a solvate {L2·(CH3CN)п } of «straw» color (360 nm) and phase II (lower layer) contains solvated complex {[Ce (III) (ОН) 2 ·L 1 ·(CH 3 CN) 2 ]·(CH 3 CN)n} of «blue» color (640 nm). The use of these solvates allows determination of Ce(IV) in the range 2.2 ч 50.1 μg/cm3 (y = 0.5526с + 0.0575, R2 = 0.9917, ε360 = 6.2·103) and 4.2 ч 84.0 μg/cm3 (y = 0.1862c + 0.0265, R2 = 0.9952, ε640 = 2.05·103), respectively. The revealed dependence was used for indirect (volumetric) determination of Ce(IV) (y = -0.7857c + 20.4440, R2=0.9988). The methods was tested on standard samples of mineral origin and herbal pharmaceutical preparations.

Colorimetric Determination of Certain Phenol Derivatives in Pharmaceutical Preparations

1981 ◽  
Vol 64 (6) ◽  
pp. 1442-1445
Author(s):  
Sayed M Hassan ◽  
Mohammed I Walash ◽  
Sanaa M El-Sayed ◽  
Abdel Malek Abou Ouf
Keyword(s):  
Pharmaceutical Preparations ◽  
Sulfanilic Acid ◽  
Diazonium Salts ◽  
Colorimetric Determination ◽  
Reaction Products ◽  
Optimum Conditions ◽  
Phenol Derivatives ◽  
The Mean ◽  
Colorimetric Methods

Abstract Simple colorimetric methods are reported for determining both acetaminophen and oxyphenbutazone. These methods are based on coupling between the phenolic compound and the diazonium salts of both sulfanilic acid and p-nitroaniline; the optimum conditions for the reactions were carefully studied. For acetaminophen, the reaction products with diazosulfanilic acid and diazo-p-nitroaniline show maximum absorbance at 480 and 425 nm, respectively. The mean percentage recoveries for authentic samples were 99.5 ± 1.1 and 100.6 ± 0.66, respectively (P = 0.05). For oxyphenbutazone, the obtained colors showed maxima at 385 nm with diazosulfanilic acid and 490 nm with diazo-p-nitroaniline reactions. The mean percentage recoveries for authentic samples were 99.8 ± 0.27 and 100.1 ± 0.57, respectively (P = 0.05). The proposed methods were successfully applied to the analysis of commercial preparations; results were statistically compared with those of other methods.

scholarly journals Indirect Spectrophotometric Methods for the Determination of Tadalafil

2015 ◽  
Vol 1 (2) ◽  
pp. 11 ◽  
Author(s):  
Safwan Mohammad Fraihat
Keyword(s):  
Oxidation Reaction ◽  
Indigo Carmine ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Blue Dye ◽  
Reaction Products ◽  
Reaction Conditions ◽  
Factors Affecting ◽  
Spectrophotometric Methods

Two spectrophotometric methods were developed for the determination Tadalafil in pharmaceutical preparations. The methods are based on the oxidation reaction with known excess amount of Ce(IV) and estimation of the unreacted amount using Indigo carmine dye (Method A) and in Methylene blue dye  (Method B). the factors affecting the reaction conditions were studied and the absorbance of absorbance of the oxidation reaction products were monitored at 610 and 600 nm for methods A and B respectively. Beer's law is obeyed in the concentration ranges 11 to 50 and 10 to 55 ppm, the limits of detection and quantification are reported. The proposed method was applied to the determination of the drug in pharmaceutical formulations and the results demonstrated that the method is equally accurate, precise and reproducible as the official methods. The validity of method was established by recovery studies with satisfactory results.

Colorimetric Determination of C-2 Unsubstituted Phenothiazines, Using Morpholine and N-Bromosuccinimide

1986 ◽  
Vol 69 (5) ◽  
pp. 821-824 ◽  
Author(s):  
Salwa R El-Shabouri ◽  
Adel F Youssef ◽  
Fardous A Mohamed ◽  
Abdel Maboud I Rageh
Keyword(s):  
Analytical Data ◽  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Colorimetric Determination ◽  
Blue Color ◽  
Decomposition Products ◽  
Wide Range ◽  
Intact Drug ◽  
Pure Compounds

Abstract A colorimetric method for quantitative determination of 6 C-2 unsubstituted phenothiazine derivatives is described. The method is based on reaction of phenothiazine derivative with morpholine and N-bromosuccinimide reagents in aqueous methanol at 60°C to produce a blue color. Beer's law is obeyed in a wide range of concentrations for all 6 compounds at 660 nm. Optimum analytical conditions were determined and the produced color is stable for at least 24 h. Analytical data for determination of the pure compounds are presented together with the application of the proposed method to analysis of some pharmaceutical preparations. The results compare favorably with those of official methods. Furthermore, the method is specific for intact drug in the presence of oxidative decomposition products. The reaction product has been isolated and identified and a possible reaction mechanism is suggested.

scholarly journals Spectrophotometric and Reverse Flow Injection Method Determination of Nitrazepam in Pharmaceuticals Using O-Coumaric Acid as a New Chromogenic Reagent

2020 ◽  
Vol 17 (1(Suppl.)) ◽  
pp. 0265
Author(s):  
Sadeem Subhi Abed
Keyword(s):  
Flow Injection ◽  
Reverse Flow ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Physical Parameters ◽  
Blue Color ◽  
Coumaric Acid ◽  
Limit Of Quantification ◽  
Reverse Flow Injection

            A spectrophotometric- reverse flow injection analysis (rFIA) method has been proposed for the   determination of Nitrazepam (NIT) in pure and pharmaceutical preparations. The method is based upon the coupling reaction of NIT with a new reagent O-Coumaric acid (OCA) in the presence of sodium periodate in an aqueous solution. The blue color product was measured at 632 nm. The variation (chemical and physical parameters) related with reverse flow system were estimated. The linearity was over the range 15 - 450 µg/mL of NIT with detection limits and limit of quantification of 3.425 and 11.417 µg mL-1 NIT,respectively. The sample throughput of 28 samples per hour was achieved. Suggested method was successfully applied for the determination of NIT in its dosage forms.

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.

Colorimetric Determination of Amoxicillin in Pure and some Pharmaceutical Formulations Via Reaction with Potassium Permanganate as Oxidant Reagent

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa
Keyword(s):  
Potassium Permanganate ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Atomic Emission ◽  
Basic Medium ◽  
Photometric Method ◽  
Colorimetric Determination ◽  
Spectrophotometric Methods ◽  
Label Claim

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.

Dc arc emission analysis of rare earth metals and their oxides with sorption preconcentration of impurities

2018 ◽  
Vol 84 (11) ◽  
pp. 9-14
Author(s):  
E. S. Koshel ◽  
V. B. Baranovskaya ◽  
M. S. Doronina
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Analytical Signal ◽  
Graphite Powder ◽  
Atomic Emission ◽  
Standard Samples ◽  
Emission Analysis ◽  
Sorption Preconcentration ◽  
Sample Shape

The analytical capabilities of arc atomic emission determination of As, Bi, Sb, Cu, Te in rare earth metals (REM) and their oxides after preparatory group concentration using S,N-containing heterochain polymer sorbent are studied on a high-resolution spectrometer “Grand- Extra” (“WMC-Optoelectron-ics” company, Russia). Sorption kinetics and dependence of the degree of the impurity extraction on the solution acidity are analyzed to specify conditions of sorption concentration. To optimize the procedure of arc atomic emission determination of As, Bi, Sb, Cu, and Te various schemes of their sorption preconcentration and subsequent processing of the resulted concentrate with the addition of a collector at different stages of the sorption process have been considered. Graphite powder is used as a collector in analysis of rare earth oxides due to universality and relative simplicity of the emission spectrum. Conditions of analysis and parameters of the spectrometer that affect the analytical signal (mass and composition of the sample, shape and size of the electrodes, current intensity and generator operation mode, interelectrode spacing, wavelengths of the analytical lines) are chosen. The evaporation curves of the determinable impurities were studied and the exposure time of As, Bi, Sb, Cu, and Te in the resulted sorption concentrate was determined. Correctness of the obtained results was evaluated using standard samples of the composition and in comparisons between methods. The results of the study are used to develop a method of arc chemical-atomic emission analysis of yttrium, gadolinium, neodymium, europium, scandium and their oxides in a concentration range of n x (10-2 - 10-5) wt.%.

Sorption of Se (IV) from aqueous solutions with subsequent determination by X-ray fluorescence analysis

2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Fluorescence Analysis ◽  
Standard Samples ◽  
Phase Contact Time ◽  
Sorbent Phase ◽  
X Ray ◽  
Fundamental Parameters ◽  
Inductively Coupled ◽  
Subsequent Determination

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.

Simultaneous Determination of Methocarbamol and Paracetamol in the Presence of Three Related Substances by Ultra Performance Liquid Chromatography

2019 ◽  
Vol 15 (5) ◽  
pp. 505-510
Author(s):  
Yanjuan Zheng ◽  
Qiushi Peng ◽  
Rui Dong ◽  
Tingyu Chen ◽  
Yi Bao ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Pharmaceutical Preparations ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Related Substances ◽  
Bulk Powder ◽  
Highly Sensitive ◽  
Optimal Protocol ◽  
Acquity Uplc

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 µg/ml for Methocarbamol, and 1-100 µg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.

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