scholarly journals Determination of Trace Amount of Pd(II) and Ni(II) with Newly Synthesized Pyrozlon Azo Bromo Phenol by Spectrophotometric Methods

2011 ◽  
Vol 8 (s1) ◽  
pp. S425-S433 ◽  
Author(s):  
Hussain J Mohammed ◽  
Azhar Y Muhi ◽  
Hayder Al Meisslemaw
Keyword(s):  
Linear Correlation ◽  
Conductivity Measurements ◽  
Optimum Conditions ◽  
Selective Method ◽  
Spectrophotometric Methods ◽  
Full Color ◽  
Color Development ◽  
The Stability ◽  
Intense Color

A sensitive and selective method has been developed for the determination of palladium(II) and nickel(II). A new reagent and two complexes have been prepared in aqueous solutions. The method is based on the chelation of metal ions with 4-(4'- antipyriyl azo ) -2-bromo phenol (APBP) to form an intense color soluble products, that are stable and have a maximum absorption at 498 nm and at 433.5 nm and εmaxof 0.21×104and.0.38×104Lmole-1cm-1for Pd(II) Ni(II) respectively. A linear correlation of (0.2 - 3) and (0.6 -2.2) ppm for Pd(II) Ni(II) respectively. The stoichiometry of both complexes was found to be 1:2 (metal:ligand). The effect of various cations and anions on Pd(II) and Ni(II) determination have been investigated. The stability constants Pd(II) and Ni(II) were 0.37×108, 0.38×108L mol-1respectively. The conductivity measurements for complexes are consistent with those expected for an electrolyte. The optimum conditions for full color development for described methods were applied satisfactorily to synthetic mixtures samples and biological samples.

scholarly journals Spectrophotometric determination of micro amount of palladium(II) platinum (II)By using pyrazolone azo resorcinol

2011 ◽  
Vol 8 (4) ◽  
pp. 996-1004
Author(s):  
Baghdad Science Journal
Keyword(s):  
Metal Ions ◽  
Stability Constants ◽  
Linear Correlation ◽  
Conductivity Measurements ◽  
Selective Method ◽  
Relative Standard ◽  
Relative Errors ◽  
The Stability ◽  
Intense Color

A sensitive and selective method have been developed for the determination of palladium (II)and platinum (II) . A new reagent and two complexes have been prepared in ethanolic solutions .The method is based on the chelation of metal ions with 4-(4?- pyrazolon azo) resorcinol (APAR) to form intense color soluble products, that are stable and have a maximum absorption at 595 nm and at 463 nm and ?max of 1.11×10 4 and.1.35 ×104 Lmole-1cm-1 for Pd(II) Pt(II) respectively. A linear correlation of (1.4 – 0.2) and (3.2 -0.4 ) ppm for pd(II) pt(II) respectively .The stability constants , relative errors , a relative standard deviations for Pd(II) and Pt(II) were 0.40×105 , 0.4×104 L mol-1 ,0.34 - 0.21% and 2.4 – 0.91% respectively. The conductivity measurements for complexes are consistent with those expected for an electrolyte. The proposed method was successfully applied to the analysis of dust and synthetic mixtures without any preliminary concentration or sparation.

scholarly journals Synthesis ,spectroscopic study of Antipyryl azo 2-Naphthol and use it as new reagent for determination of Co(II) and Cu(II)

2013 ◽  
Vol 10 (3) ◽  
pp. 977-985
Author(s):  
Baghdad Science Journal
Keyword(s):  
Optimum Condition ◽  
Spectroscopic Study ◽  
Aqueous Medium ◽  
Stability Constants ◽  
Spectrophotometric Method ◽  
Full Color ◽  
Color Development ◽  
The Stability ◽  
Sensitive Spectrophotometric Method

A simple ,accurate and sensitive spectrophotometric method has been developed the determination of Cobalt(II) and Cupper (II) .The method is based on the chelation of Co(II) and Cu(II) ions with 4-(4´-pyrazolon azo) -2-Naphthol(APAN) in aqueous medium . The complexes have a maximum absorption at (513) and (506) nm and ? max 0.531×10 4 and 0.12×10 5 L.mol -1.cm -1 for Co(II) and Cu(II) respectively .The reagent and two complexes have been prepared in ethanolic solution.The stoichiometry of both complexes were found to be 1:2 (metal :legend) .The effects of various cations and anions on Co(II) and Cu(II) determination have been investigated .The stability constants and standard deviations for Co(II) and Cu(II) 0.291 x107 ,0.909X108 L.mol -1 ,(0.291) and (0.332) respectively .The optimum condition for full color development for described methods were applied satisfactorily to synthetic samples.

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

Continuous-flow determination of serum inorganic phosphate with a single reagent--the vanadomolybdate method re-evaluated.

1977 ◽  
Vol 23 (7) ◽  
pp. 1275-1280 ◽  
Author(s):  
H Baadenhuijsen ◽  
H E Seuren-Jacobs ◽  
A P Jansen
Keyword(s):  
Acid Medium ◽  
Inorganic Phosphate ◽  
Room Temperature ◽  
Visible Range ◽  
Color Development ◽  
Optimum Reaction ◽  
The Stability ◽  
Serum Inorganic Phosphate ◽  
Tungsten Lamp

Abstract The merits of the vanadomolybdate method in the determination of inorganic phosphate are highly underestimated with regard to the simplicity of the method and the stability of both the reagents and the color that is formed. The absorption curve of the phosphovanadomolybdate complex, with its maximum at 335 nm, extends into the visible range of the spectrum. This permits measurements with inexpensive tungsten-lamp colorimeters. On-stream dialysis is best done in a nitric acid medium, 0.15 mol/liter. Paralleled by the change in the H2PO4-/H3PO4 ratio, appreciable protein binding and poor dialysis efficiency are seen at lower acid concentrations (pH greater than 1.0). Optimum reaction-mixture concentrations of vanadium and molybdenum appeared to be respectively 0.2 and 5 mmol/liter up to 3 mmol of phosphate per liter, in a final acid medium of 0.2 mol/liter, concentrations considerably lower than those used in some studies published earlier. Color development with the stable combined reagent is complete after only 20 s at room temperature and the color is stable for at least 2 h. Figures on precision and accuracy demonstrate the reliability of the method.

Validated Spectrophotometric Determination of Rizatriptan Benzoate in Pharmaceutical Formulations using Alizarin Derivatives

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
El Sheikh R ◽  
Hassan W. S. ◽  
Gouda A. A. ◽  
Al OwairdhiA. ◽  
Al Hassani K K H
Keyword(s):  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Alizarin Red ◽  
Rizatriptan Benzoate ◽  
Spectrophotometric Methods ◽  
Relative Standard

Two simple, sensitive, accurate, precise and economical spectrophotometric methods have been developed and validated for the determination of rizatriptan benzoate (RZT) in pure form and pharmaceutical formulations. These methods were based on the formation of charge transfer complex between RZT as n-electron donor and alizarin red S (ARS) or quinalizarin (Quinz) as π-acceptor in methanol to form highly colored chromogens which showed an absorption maximum at 532 and 574 nm using ARS and Quinz, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Under the optimum conditions, Beer’s law is obeyed in the concentration ranges 1.0-16 and 2.0-20 g mL-1 using ARS and Quinz, respectively with good correlation coefficient (r2 ≥ 0.9996) and with a relative standard deviation (RSD% ≤ 1.16). The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The methods were successfully applied to the determination of RZT in its pharmaceutical formulations and the validity assesses by applying the standard addition technique. Results obtained by the proposed methods for the pure RZT and commercial tablets agreed well with those obtained by the reported method.

scholarly journals Selective and Stability-Indicating Methods for the Simultaneous Determination of Mexiletine Hydrochloride and/or Its Related Substance: 2,6-Dimethylphenol

2008 ◽  
Vol 91 (4) ◽  
pp. 720-730
Author(s):  
Tarek S Belal ◽  
Rim S Haggag ◽  
Rasha A Shaalan
Keyword(s):  
Sodium Dodecyl ◽  
Coupling Reaction ◽  
Parent Drug ◽  
Related Substance ◽  
Selective Determination ◽  
Stability Indicating ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
The Stability

Abstract Four simple, rapid, sensitive, and selective analytical procedures were developed for determination of mexiletine hydrochloride (MX) and/or its related substance: 2,6-dimethylphenol (DMP). The latter is a synthetic impurity for which a maximum pharmacopeial limit is defined. The first method depends on derivative-ratio spectrophotometry, for which the first-derivative signals of the ratio spectra at 259 nm ( = 3 nm) are selected for the determination of MX. The second method is based on the spectrofluorometric measurement of MX in alkaline solution in the presence of 15 mM sodium dodecyl sulfate micellar medium at 292 nm (Ex 260 nm). The third method is based on liquid chromatographic (LC) separation of MX and DMP on an RP-C8 column with a mobile phase consisting of 50 mM Na2HPO4acetonitrile (60 + 40, adjusted to pH 2.4), and quantification of the analytes is achieved with UV detection at 212 nm based on peak area. The fourth method uses the coupling reaction of DMP with 2,6-dibromoquinone-4-chlorimide (DBQC) in borate buffer to form an intensely colored product that was spectrophotometrically measured using first-derivative amplitudes at 670 nm ( = 6nm) for the determination of DMP. Different variables affecting each method were carefully investigated and optimized. The reliability and analytical performance of the proposed methods, including linearity, range, precision, accuracy, and detection and quantitation limits, were statistically validated. The first 3 methods were successfully applied for the stability-indicating determination of MX in laboratory-prepared mixtures with DMP, as well as for the determination of MX in capsules. Also, the LC and the DBQC spectrophotometric methods permitted the selective determination of DMP in the presence of a large excess of the parent drug at or near the pharmacopeial limit (0.11).

DETERMINATION OF T.N.T. (2,4,6-TRINITROTOLUENE) IN AIR

1941 ◽  
Vol 19b (3) ◽  
pp. 86-89 ◽  
Author(s):  
Kingsley Kay
Keyword(s):  
Sodium Hydroxide ◽  
Field Tests ◽  
Practical Method ◽  
Optimum Conditions ◽  
Accurate Comparison ◽  
The Stability ◽  
Red Coloration

A practical method for determining the concentration of T.N.T. in workroom atmospheres has been developed and has been given successful field tests. The accuracy of the method described is approximately ± 10%. The method is a comparative one, depending upon the red coloration produced when 2,4,6-trinitrotoluene in acetone is treated with a solution of sodium hydroxide in water. The stability of the coloration has been studied and the optimum conditions of temperature and concentrations of reactants have been determined. In addition the range of colour that allows the most accurate comparison has been evaluated. Minor refinements are at present in progress with a view to increasing the accuracy of the test.

scholarly journals Spectrophotometric Methods for the Determination of Ceftiofur and Tulathromycin in Bulk and Dosage Forms

2020 ◽  
pp. 34-47
Author(s):  
Noha Salem Rashed ◽  
Amany Mohmed Abdelazeem ◽  
Fatma Ahmed Fouad
Keyword(s):  
Absorption Maximum ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Veterinary Drugs ◽  
Binary Complex ◽  
Eosin Y ◽  
Optimum Conditions ◽  
Spectrophotometric Methods

Two simple, accurate and precise spectrophotometric methods were developed for the determination of two veterinary drugs, ceftiofur and tulathromycin in pure form as well as in pharmaceutical formulations. The first one (Method A) based on the reducing action of ceftiofur on Fe (ΙΙΙ) to Fe (ΙΙ) in its complex with 1, 10- phenanthroline (ferrin complex) to give the orange-red colored ferroin complex that exhibits an absorption maximum at 511 nm. Ceftiofur exhibited good linearity in the concentration range of 0.3-3.0 μg mL−1.The second method (Method B) depended on formation of a binary complex between tulathromycin and eosin Y in in the presence of carboxy methylcellulose as surfactant. Under the optimum conditions, the binary complex showed absorption maxima at 556 nm. The method obeyed Beer’s law over concentration range of 1.0–15.0 μg mL−1.  The proposed methods were used for determination of the studied drugs in pharmaceutical formulation; maxfur® powder and draxxin® injections with mean recoveries of 99.57and 99.71%, respectively. The validity of the methods was further proved by applying the standard addition technique. A proposal of the reactions pathways were described.

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