scholarly journals Solvent Extraction Studies on Copper(II) and Silver(I) Complexes of Bis(4-hydroxypent-2-ylidene)diaminoethane: Composition of Extracted Copper(II) Species

2011 ◽  
Vol 8 (4) ◽  
pp. 1864-1871 ◽  
Author(s):  
P. O. Ukoha ◽  
F. I. Nwabue ◽  
L. N. Obasi
Keyword(s):  
Solvent Extraction ◽  
Equilibrium Constant ◽  
Molar Absorptivity ◽  
Low Ph ◽  
Water Soluble ◽  
Continuous Variation ◽  
Maximum Absorption ◽  
Ionic Complexes ◽  
Elemental Analyses

Copper(II) complexes of bis(4-hydroxypent-2-ylidene)diaminoethane (BHPDE) were prepared by extractive method. Job’s continuous variation and equilibrium constant methods, as well as spectral and elemental analyses were applied in the determination of the nature of extracted species. The results indicate the formation of mixed ionic complexes of the types Cu(H2L)X2, Cu(H2L)2X2and CuL (where H2L = BHPDE and X = NO3-, CIO4-, Cl-or ½SO42-). Cu(H2L)X2and Cu(H2L)2X2predominate at low pH extractions while CuL chelate predominates at high pH extraction. The complexes exist in two isomeric forms, the blue readily-water-soluble and the violet less water-soluble forms. Both complexes show maximum absorption at 540 nm and molar absorptivity values of about 2.0 x 102dm3mole-1cm-1.

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 Solvent Extraction And Spectrophotomteric Determination Of Cu(Ii) With Dicyclohexyl - 18- Crown-6

2013 ◽  
Vol 10 (3) ◽  
pp. 997-1004
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Solvent Extraction ◽  
Correlation Coefficient ◽  
Extraction Efficiency ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Coloured Complex

Liquid-Liquid Extraction of Cu(II) ion in aqueous solution by dicyclohexyl-18-crown-6 as extractant in dichloroethane was studied .The extraction efficiency was investigated by a spectrophometric method. The reagent form a coloured complex which has been a quantitatively extracted at pH 6.3. The method obeys Beer`s law over range from (2.5-22.5) ppm with the correlation coefficient of 0.9989. The molar absorptivity the stoichiometry of extracted complex is found to be 1:2. the proposed method is very sensitive and selective.

Spectrophotometric investigation of sensitive complexing agents for the determination of zinc in serum.

1985 ◽  
Vol 31 (8) ◽  
pp. 1310-1313 ◽  
Author(s):  
R Homsher ◽  
B Zak
Keyword(s):  
Trace Metal ◽  
Atomic Absorption ◽  
Serum Zinc ◽  
Atomic Absorption Spectrophotometry ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
The Other ◽  
Complexing Agents ◽  
Absorption Spectrophotometry

Abstract Of two sensitive complexometric reagents for the colorimetry of serum zinc that we investigated, one, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP), was found to be a potentially useful compound for trace-metal determinations. It has a high molar absorptivity (120 000 L mol-1 cm-1) but is not convenient to use because it is not very soluble in water. The other reagent, a related pyridylazo compound, is 2-(5-bromo-2-pyridylazo)-5-(N-n-propyl-N-3-sulfopropylamino)phenol (5-BR-PAPS). It seems better suited for use in routine zinc determinations because, besides being water soluble, it has a higher molar absorptivity, 130 000 L mol-1 cm-1. Results by the proposed method developed with 5-Br-PAPS correlated well with those by atomic absorption spectrophotometry. The between-run CV for control sera was less than 5%; the within-run CV (same controls) was less than 4%.

Spectrophotometric Determination of p-aminobenzoic acid via Diazotization and Coupling reaction

2021 ◽  
pp. 5313-5318
Author(s):  
Rana S. Al-Saffar ◽  
Safaa A. Zakaria ◽  
Nabeel S. Othman
Keyword(s):  
Folic Acid ◽  
Hydrochloric Acid ◽  
Sodium Nitrite ◽  
Azo Dye ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Good Sensitivity ◽  
Aminobenzoic Acid

A simple and accurate spectrophotometric method to assay p-aminobenzoic acid (PABA) has been suggested. The method based on the diazotization of PABA via reaction with nitrite ions which liberated in the medium through the reaction of sodium nitrite with hydrochloric acid, then coupling the dizotised-PABA(D-PABA)with 1-naphthylamine -7-sulphonic acid (1-NASA) to form an intense colored pink azo dye ,it is water-soluble , very stable and has a maximum absorbance at 525 nm. The absorbance was increase with the increasing of PABA amounts in the solution, and the linearity from 2.5 to70 µg in 10 ml (0.25to7 µg.ml-1).The molar absorptivity and Sandell ҆s sensitivity values have been calculated they equal to 3.6057x104 L.mol-1 cm -1 and 0.0037993 µg. cm-2 respectively. The two values above demonstrated a good sensitivity of the suggested method. The method has been used in estimated PABA resulted from analysis of folic acid in tablet.

scholarly journals DEVELOPMENT OF EXTRACTIVE SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF IRON (III) WITH SCHIFF BASE 2-[(2-HYDROXYPHENYLIMINO) METHYL]-4-NITROPHENOL

2016 ◽  
Vol 8 (4) ◽  
pp. 89 ◽  
Author(s):  
Datta B. Mandhare ◽  
Vasant D. Barhate
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Maximum Absorption ◽  
Ratio Method ◽  
Pharmaceutical Samples ◽  
Mole Ratio Method ◽  
Ph Range

Objective: A simple spectrophotometric method has been developed for the determination of Iron (III) by using Schiff base 2-[(2-hydroxyphenylimino) methyl]-4-nitrophenol [HPIMNP].Methods: HPIMNP extracts Fe (III) quantitatively (99.95%) into chloroform from an aqueous solution of pH range 4.0-6.0.Results: The chloroform extracts show maximum absorption at 510 nm (λ max). Beer’s Law is obeyed over the Fe (III) concentration range of 0.5 to 20.0 µg/ml. The Molar absorptivity and Sandell’s sensitivity for Fe–HPIMNP system is 5000 L mol ˉ1 cmˉ1 and 0.011 µg cmˉ2respectively. The composition of extracted species is found to be 1: 3 [Fe-HPIMNP] by Job’s continuous variation and Mole-ratio method. Interference by various ions has been studied.Conclusion: The proposed method is rapid, sensitive, reproducible and accurate and it has been satisfactory applied for the determination of Iron in Pharmaceutical Samples.

scholarly journals Spectrophotometric Study of Ternary Complex Forming Systems of Some Lanthanide Metal Ions with Eriochrome Cyanine R in Presence of Cetylpyridinium Bromide for Microdetermination

2011 ◽  
Vol 8 (3) ◽  
pp. 1264-1274 ◽  
Author(s):  
A. S. Dhepe ◽  
A. B. Zade
Keyword(s):  
Metal Ions ◽  
Cationic Surfactant ◽  
Molar Absorptivity ◽  
Ternary Complexes ◽  
Water Soluble ◽  
Stoichiometric Ratio ◽  
Cetylpyridinium Bromide ◽  
Lanthanide Metal ◽  
Colored Complexes

Study of coordination compounds of lanthanide elements has received a great attention due to growing applications in science and technology. Number of chromogenic reagents form water soluble colored complexes with lanthanides. Eriochrome cyanine R (ECR) a member of triphenylmethane type of dye has been reported to form green colored complexes with lanthanides and has been used for microdetermination of these metal ions. Addition of cationic surfactant, Cetylpyridinium bromide (CPB), a cationic surfactant sensitizes the color reactions of Gd(III), Tb(III), Dy(III), Ho(III) and Lu(III) with ECR. Formation of water soluble, highly colored ternary complexes with a considerable bathochromic shift of about 50 nm in presence of surfactant has been observed. Optimum reaction conditions and other analytical parameters were also evaluated. Stoichiometric ratio 1:3:3 of Ln: ECR: CPB are responsible for the observed rise in molar absorptivity and sensitivity. Beer’s law was obeyed between 0.50 to 13.00 ppm. Effective photometric range and molar absorptivity of these ternary complexes have been calculated. Effect of some common interfering ions on determination of these lanthanide metal ions was studied. A simple, rapid and highly sensitive spectrophotometeric method has been proposed for the determination of metal ions understudy.

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 Solvent Extraction of Thorium Using 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Quang Hieu Tran ◽  
Van Tan Le ◽  
Van Cuong Nguyen
Keyword(s):  
Aqueous Solution ◽  
Solvent Extraction ◽  
Molar Absorptivity ◽  
Tolerance Limits ◽  
Acidic Aqueous Solution ◽  
Selective Method ◽  
Chloroform Layer ◽  
Effects Of Ph ◽  
Synthetic Solution

A rapid, sensitive, and selective method for determination of thorium based on the complex withortho-ester tetra-azophenylcalix[4]arene (TEAC) was described. In the presence of pH of 4–6, TEAC-Th(IV) complex is extracted from an acidic aqueous solution into chloroform layer. The absorbance intensity of complex was measured by UV-Vis spectrometer at 525 nm and the molar absorptivity was found to be 2.4 × 104. Beer’s law was obeyed in the range of 1.0 to 25 × 10−5 M thorium(IV). The effects of pH, TEAC concentration, and shaking time were also studied. The tolerance limits for several metal ions were calculated. The proposed method was applied to the determination of thorium in synthetic solution and in the monazite sand samples with good results.

scholarly journals Spectrophotometric determination of metoclopramide medicine in bulk form and in pharmaceuticals using orcinol as reagent

2016 ◽  
Vol 29 (2) ◽  
pp. 85-91
Author(s):  
Hanaa Khazal Abdulghareeb Taha ◽  
Mohauman Mohammed Al-Rufaie ◽  
Zahraa Yosif Motaweq
Keyword(s):  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Azo Coupling ◽  
Average Recovery ◽  
Yellow Color ◽  
Relative Standard ◽  
Naoh Solution ◽  
Official Procedure

Abstract A modern, accurate, simple and sensitive spectrophotometric procedure is tested for the appreciation of metoclopramide medicine as perspicuous form, as well as in various kinds of pharmaceutical dosages. The procedure depends on the interaction of metoclopramide (MCP) medicine and orcinol reagent by utilizing azo coupling reaction. The orcinol in NaOH solution middle to give a latterly ligand which reacts with copper (II) to output the complex with strong yellow color at 50°C. The resulting complex is water soluble, stable and can be determined spectrophotometrically at wavelength 459 nm. The calibration curve absorbance vs. concentration was established in the concentration range 0.6-12 ppm, and the curve followed the Beer’s law in this range. The procedure precision is given by the average recovery of 99.91% sequentially, as well as by the average relative standard deviation 0.70%, related to the amount of drug. The sensitivity is established at molar absorptivity 1.9044×104 l‧cm-1‧mol-1. The Sandell sensitivity is tested as 0.002 μg/cm2. The analytical results for the tested procedure agree with the official procedure. The interferences from medicine additives were tested. The established procedure is successfully examined on the appreciation of MCP in diverse kinds of pharmaceuticals.

scholarly journals Spectrophtometric determination of Hydrochlorothiazaide by oxidative coupling with O-Phenylendiamine

2019 ◽  
Vol 24 (2) ◽  
pp. 46
Author(s):  
Rahma Abdul Hameed Hasan1 ◽  
Ali Ibraheem Khaleel2
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Sensitivity Index ◽  
Medium Ph ◽  
Oxidative Coupling Reaction ◽  
Stable Product ◽  
Orange Color

This study includes the development of a new sensitive spectrophotometric method for the determination of a hydrochlorothaizide in aqueous solution and pharmaceultical preparations. The method is based on the oxidative coupling reaction of hydrochlorothaizide with O-phenylendiamine reagent in a acidic medium pH 1.5 in the presence of potassium ferricyanide  to produce an intense orange color, water soluble and stable product , which exhibits maximum absorption at 450 nm. Beer’s law is obeyed over the concentration arange 6 to 48 µg.ml-1 of hydrochlorothaizide, with a molar absorptivity of  3602.17  L.mo1-1 .cm -1 , Sandell’s sensitivity index of 0.03 µg.cm-2 , relative error range not more than 0.215% , and D.L 0.0835µg.ml-1 . The method has been successfully applied for the determination of hydrochlorothaizide in tablets.   http://dx.doi.org/10.25130/tjps.24.2019.030

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