Colorimetric Determination of Catecholamines by 2,3,5-Triphenyltetrazolium Chloride

El-Rabbat, Nawal A.; Omar, Nagwa M.

doi:10.1002/jps.2600670612

Cited by 23 publications

(9 citation statements)

References 11 publications

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“…Many spectrophotometric methods have been proposed for the determination of catecholamines using several reagents such as vanillin [13], 2,3,5-triphenyltetrazolium chloride [14], semicarbazide hydrochloride in the presence of potassium persulphate [15], barbituric acid [16,17], metaperiodate [18], isoniazid in presence of Nbromosuccinamide [19], 4-aminoantipyrine in the presence of copper tetramine [20] polyphenol oxidase enzyme [21], neotetrazolium chloride [22], p-dimethylaminocinnamaldehyde [23], diazotized sulphanilamide in the presence of molybdate [24] and molibdophosphoric acid in sulphuric acid medium [25], anisidine in the presence of sodium metaperiodate [26] and benzidine in the presence of sodium metaperiodate [27].. However, most of these methods suffer from several disadvantages such as the need of the long waiting times [13 -16] or instability of the coloured species [19], complicated procedure [21], require nonaqueous media [23,24], or has not been applied to pharmaceutical formulations [25].…”

Section: (I) (Ii) (Iii)mentioning

confidence: 99%

Sensitive spectrophotometric method for determination of catecholamines in pure and pharmaceutical formulations

Al-Ghabshaa¹,

Al-Enizzi²,

Al-Abdaly³

2007

J.Edu.Sci.

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Accepted Received 5/12/2006 11/9/2006 ‫ال‬ ‫ملخص‬ ‫أمينات‬ ‫أدوية‬ ‫من‬ ‫امية‬ ‫مايكروغر‬ ‫كميات‬ ‫لتقدير‬ ‫وحساسة‬ ‫سهمة‬ ‫طيفية‬ ‫يقة‬ ‫طر‬ ‫تطوير‬ ‫تم‬ ‫ينالين‬ ‫ادر‬ ‫و‬ ‫ودوبامين‬ ‫دوبا‬ ‫بالمثيل‬ ‫المتمثمة‬ ‫الكاتيكول‬ . ‫األدوية‬ ‫تمك‬ ‫أكسدة‬ ‫عمى‬ ‫يقة‬ ‫الطر‬ ‫تعتمد‬ ‫الكاشف‬ ‫مع‬ ‫الناتج‬ ‫الثنائي‬ ‫الحديد‬ ‫ومفاعمة‬ ‫حامضي‬ ‫وسط‬ ‫في‬ ‫الثالثي‬ ‫الحديد‬ ‫بوساطة‬ 10،1 -‫في‬ ‫األدوية‬ ‫تمك‬ ‫تقدير‬ ‫في‬ ‫بنجاح‬ ‫يقة‬ ‫الطر‬ ‫تطبيق‬ ‫أمكن‬ ‫و‬ ‫اغ‬ ‫السو‬ ‫اد‬ ‫مو‬ ‫وجود‬ ‫من‬ ‫تداخالت‬ ‫الصيدالنية‬ ‫اتها‬ ‫مستحضر‬ . AbstractA sensitive and simple spectrophotometric method is developed for the determination of catecholamine drugs namely; methyldopa, dopamine and adrenaline in pure and pharmaceutical preparations. The method is based on the oxidation of the cited drugs with iron(III) in acidic medium and the liberated iron(II) reacts with 1,10-phenanthroline. The ferroin complex is colorimetrically measured at 510 nm against reagent blank. Beer's law was valid over the concentration ranges of 0.1-2.8, 0.1-2.0, and 0.2-6.0μg/ml and the molar absorptivities are 1.851×10 5 , 1.544×10 5 and 4.331×10 4 l.mol -1 cm -1 for methyldopa, dopamine and adrenaline respectively. The common excipients and additives did not interfere in their determinations. The proposed method was successfully applied to the assay of the above drugs in various dosage forms.

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Section: (I) (Ii) (Iii)mentioning

confidence: 99%

Sensitive spectrophotometric method for determination of catecholamines in pure and pharmaceutical formulations

Al-Ghabshaa¹,

Al-Enizzi²,

Al-Abdaly³

2007

J.Edu.Sci.

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“…These include titrimetry (Amin, 1986), spectrophotometry (El-Rabbat and Omar, 1978;Davidson, 1984;Walash et al, 1985;Issopoulos, 1989;Ribeiro et al, 2005;Krishan et al, 1990;Zivanovic et al, 1991;Babu et al, 2001), and chromatography (Hjemdahl, 1984;Das Gupta and Dhruv, 1986;Rosa et al, 1995;Benza et al, 1996). Furthermore, cyclic voltametry (Ali and Sami, 2005), electrochemical oxidation and kinetic methods (James et al, 2006;Matthieu et al, 2006) have been cited.…”

Section: Introductionmentioning

confidence: 96%

A new spectrophotometric method for the determination of methyldopa

Gadkariem

Ibrahim

Kamil

et al. 2009

Saudi Pharmaceutical Journal

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A new, simple and low cost spectrophotometric method for the determination of methyldopa in pharmaceutical preparations was developed. The method was based on the coupling of methyldopa with 2,6-dichloroquinone-4-chlorimide (DCQ). The absorbance maximum (λ max) of the resulted colored product was at 400 nm. Different buffers were used to determine the optimal pH for the reaction. About 1% w/v acetate buffer with pH 8.0 gave the optimal pH required for the reaction. Of the different solvents tried, water and ethanol were found to be the most suitable solvents. Beer's law was obeyed in concentration range of 4-20 μg/ml methyldopa. The correlation coefficient was found to be (r = 0.9975). The limit of detection and limit of quantification were 1.1 μg/ml and 3.21 μg/ml, respectively. The reaction ratio between methyldopa and DCQ was studied and found to be 1:3. The work included the study of the possible interference of hydrochlorothiazide found in combination with methyldopa tablets. The method was validated and results obtained for the assay of two different brands of methyldopa tablets were compared with the BP method (colorimetric). The repeatability and reproducibility of the developed method were evaluated and the obtained results quoted. The derivative formed as a result of the reaction of methyldopa with DCQ was isolated and its possible mechanistic pathway was suggested.

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“…Numerous analytical techniques including spectrofluorimetric [18][19][20], chromatographic [21][22][23][24][25][26][27] and flow injection [28,29] are now available for the analysis of MD in biological fluids and pharmaceutical formulations. Also, many spectrophotometric methods have been proposed for the determination of catecholamines including MD [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Determination of Hydrochlorothiazide and Methyldopa in Tablets Using First Derivative Spectrophotometry and PLS

Omran

2007

Al-Azhar Bulletin of Science

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Two new analytical methods are described as convenient and useful alternatives for simultaneous determination of hydrochlorothiazide (HCTZ) and methyldopa (MD) in their combinations. The first method depends on the first order derivative spectrophotometry by measuring the amplitudes at zero-crossing wavelengths of 286 and 270 nm for HCTZ and MD, respectively. In the second method, partial least squares (PLS) analysis of the ultraviolet absorption spectra of the samples in the 240-340 nm region was applied. The methods were calibrated between 3.5 and 35.7 g mL -1 for HCTZ and between 2.5 and 25.3 g mL -1 for MD. For PLS chemometric calibration a concentration set of random mixture consisting of the two drugs in ethanol was prepared. The absorbance data in UV spectra and their dA/d values were measured for the 24  points considering = 4 nm. The calibration of the PLS method involves both absorbance-concentration and dA/d-concentration data matrices. The numerical values were calculated by using Matlab version 6.5 and origin 7.0 software. The results of the methods were statistically compared with each other and a good harmony was found. The developed calibrations were successfully applied for assaying the pharmaceutical formulation of Aldoril  tablets.

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Colorimetric Determination of Catecholamines by 2,3,5-Triphenyltetrazolium Chloride

Cited by 23 publications

References 11 publications

Sensitive spectrophotometric method for determination of catecholamines in pure and pharmaceutical formulations

Sensitive spectrophotometric method for determination of catecholamines in pure and pharmaceutical formulations

A new spectrophotometric method for the determination of methyldopa

Simultaneous Determination of Hydrochlorothiazide and Methyldopa in Tablets Using First Derivative Spectrophotometry and PLS

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