Effective spectrophotometric study of the complexation reactions of 2-(2-pyridylazo)-1-naphthol-4-sulphonic acid with Zn(II) and Cd(II) using the SQUAD-G program

1982 ◽  
Vol 47 (10) ◽  
pp. 2654-2675 ◽  
Author(s):  
Luděk Jančář ◽  
Josef Havel ◽  
Vlastimil Kubáň ◽  
Lumír Sommer
Keyword(s):  
Aqueous Medium ◽  
Spectrophotometric Method ◽  
Spectrophotometric Study ◽  
Sulphonic Acid ◽  
Complexation Reactions

The existence of the red-orange protonated MLH complexes (λmax = 490 nm, εmax = 16 700 mmol-1 cm2, log *β111 = -0.51 for Zn(II) and λmax = 490 nm, εmax = 20 800 mmol-1 cm2, log *β111 = -1.28 for Cd(II)) and of the red-purple ML and ML2 complexes (λmax = 517 nm, εmax = 27 500 mmol-1 cm2, log *β112 = -2.8 and λmax = 527 nm, εmax = 61 500 mmol-1 cm2, log *β124 = -6.0 for Zn(II) and λmax = 522 nm, εmax = 27 200 mmol-1 cm2, log *β112 = -3.9 and λmax = 522 nm, εmax = 52 000 mmol-1 cm2, log *β124 = -8.2 for Cd(II) ions) was demonstrated in aqueous medium by numerical interpretation of the absorbance curves by the SQUAD-G minimization program. Conditions were proposed for development of a spectrophotometric method for the determination of Zn(II) and Cd(II) using 1-PAN-4S.

scholarly journals Investigation of the extraction equilibrium of ion-association complexes of molybdenum (VI) with some polyphenols and thiazolyl blue. extraction-spectrophotometric determination of molybdenum

2005 ◽  
Vol 3 (4) ◽  
pp. 747-755 ◽  
Author(s):  
Atanas Dimitrov ◽  
Vania Lekova ◽  
Kiril Gavazov ◽  
Boyan Boyanov
Keyword(s):  
Organic Solvent ◽  
Aqueous Medium ◽  
Spectrophotometric Method ◽  
Ion Association ◽  
Extraction Process ◽  
Association Constants ◽  
Optimum Conditions ◽  
Extraction Equilibrium ◽  
Simple Extraction

AbstractThe extraction process of ternary ion-association complexes of molybdenum (VI) with some polyphenols (4-nitrocatechol, 2,3-dihydroxy naphthalene) and thiazolyl blue has been investigated by using an extraction-spectrophotometric method. The optimum conditions for their quantitative preparation in aqueous medium and subsequent extraction into an organic solvent have been found. The extraction, distribution and association constants, and the recovery factors have been calculated. The composition of the complexes has been determined. A precise, sensitive and simple extraction-spectrophotometric method for determination of molybdenum in products from ferrous metallurgy has been developed.

Direct spectrophotometric method for the determination of cobalt with indane 1,2,3-trionetrioxime in aqueous medium

1987 ◽  
Vol 92 (1-3) ◽  
pp. 57-63 ◽  
Author(s):  
D. Mallikarjuna Rao ◽  
K. Hussain Reddy ◽  
D. Venkata Reddy
Keyword(s):  
Aqueous Medium ◽  
Spectrophotometric Method

scholarly journals Study of Complex Formation Between Iodoquinol (IQ) and Co2+, Mn2+, Cd2+, Pb2+and Zn2+Cations in Binary Aqueous / Non-aqueous Solvent Using Spectrophotometry

2007 ◽  
Vol 4 (4) ◽  
pp. 581-586 ◽  
Author(s):  
A. Nezhadali ◽  
H. A. Hosseini ◽  
P. Langara
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Stability Constants ◽  
Spectrophotometric Method ◽  
Formation Constants ◽  
The Other ◽  
Aqueous Solvent ◽  
The Stability ◽  
Complexation Reactions

The complexation reactions between iodoquinol and Co2+, Mn2+, Cd2+, Pb2+and Zn2+cations were studied in different DMF/H2O binary mixtures at the ionic strength of 0.1(using NaNO3).The spectrophotometric method was used for the determination of formation constants and the stoichiometries. The stoichiometry of the complexes is established 1:1 by Job's and mole ratio methods. It was found that the stability constants of the complex formed between the ligand (IQ) and the cations in the all cases increase with increasing of the non-aqueous solvent. In the most cases the maximum formation constants between Zn2+ion and IQ were obtained respect to the other cations.

scholarly journals Validated Spectrophotometric Method to Assay of B6 and B3 Vitamins in Pharmaceutical Forms Using Potassium Iodide and Potassium Iodate

2015 ◽  
Vol 60 ◽  
pp. 113-119 ◽  
Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal
Keyword(s):  
Comparative Study ◽  
Aqueous Medium ◽  
Potassium Iodide ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Potassium Iodate ◽  
Pyridoxine Hydrochloride ◽  
Iodide Ions ◽  
Significant Difference

A simple, precise and reliable spectrophotometric method for the determination of pyridoxine hydrochloride (vitB6) and nicotinamide (vitB3) in pure form and pharmaceutical formulations has been described. The method is based on the reaction of studied vitamin with a mixture of potassium iodide and potassium iodate in aqueous medium at (250.5oC) to form yellow colored tri iodide ions (I3-). The reaction is followed spectrophotometrically by measuring the absorbance at 290, 335 and 288, 350 nm for vitB6 and vitB3 respectively. Beer's law was obeyed in the range of 0.5-20.0 μg mL-1 for all procedures. Molar absorptivities were found to be 1.49×104, 1.93×104 and 0.89×104, 1.25×104 L mol-1 cm-1, for determination of vitB6 and vitB3 at 290, 335 and 288, 350 nm respectively. The proposed method has been applied to determine the components in commercial forms with no interference from the excipients. A comparative study between the suggested procedures and the official methods showed no significant difference between the two methods.

Micro Determination of Molybdenum (VI) with Phenylazoxine S Dye

1968 ◽  
Vol 23 (2) ◽  
pp. 144-146 ◽  
Author(s):  
S. S. Goyal ◽  
J. P. Tandon
Keyword(s):  
Metal Ion ◽  
Sensitivity Coefficient ◽  
Sulphonic Acid ◽  
Water Soluble ◽  
Molar Ratio ◽  
Colour Reaction ◽  
Chemical Studies ◽  
Ph Range ◽  
Complexation Reactions

Micro determination of molybdenum (VI) with 7-phenylazo-8-hydroxyquinoline-5-sulphonic acid is described. Molybdenum (VI) forms yellow, water souble complex in the pH range 2.5 — 5.5. 1:1 (M:L) stoichiometry has been established by (i) JOB’s and (ii) molar ratio methods. The colour reaction is instantaneous and the colour intensity remains unchanged for about 24 hours. The Beer's law is obeyed from 0.2 to 8.0 ppm of molybdenum per ml. The molecular extinction coefficient of the complex has been found to be E400 mµ =1.38 × 104, giving Sandell's sensitivity coefficient 0.0069 μg of molybdenum per cm2.The values of formation constant (log K) and free energy of formation (JF°) obtained by three methods are 5.40 ± 0.3. 5.20 ± 0.15, 5.62 ± 0.03 and (-7.50 ± 0.40, —7.22 ± 0.20, —7.80 ± 0.04 K.cals) respectively. The interference due to a number of anions and cations in the determination of molybdenum (VI) has also been studied.Azoxine S dyes having the general formula:(where R represents substituted benzene ring)have been found to form yellow, water soluble complexes with a number of metal ions. The dyes have been mainly used as metal ion indicators in recent years 1—5. However, a few physico-chemical studies on the complexation reactions of these dyes have also been reported 7—9.In the present investigations, a detailed study of molybdenum (VI) complex of the 7-phenylazo-8-hydroxy-quinoline-5-sulphonic acid has been carried out and it has been shown to form 1:1 complex in the pH range 2.5 to 5.5. The reaction is quite sensitive and can be used for the micro determination of molybdenum (VI).

Spectrophotometric Study on the Determination of Palladium with 4 -(5-Bromo-2-Pyridyl)-Azo-1,3-Diaminobenzene

2013 ◽  
Vol 781-784 ◽  
pp. 51-54
Author(s):  
Wei Qu ◽  
Cheng Ying Zhou
Keyword(s):  
Sulfuric Acid ◽  
Absorption Coefficient ◽  
Absorption Spectra ◽  
Spectrophotometric Method ◽  
Palladium Catalysts ◽  
Spectrophotometric Study ◽  
Heating Time ◽  
Complex Effect ◽  
Interfering Ions

This document develops a new spectrophotometric method for the determination of palladium with 4-(5-bromo-2-pyridyl)-azo-1,3-diaminobenzene, in a medium of 1.80mol/L sulfuric acid, at the maximum wavelength of 566nm. Absorption spectra of reagent and complex, effect of acidity, composition of complex and heating time for color reaction are discussed. More than 30 kinds of interfering ions are determined. The interference of Pb2+, Ag+ and Cr6+ are eliminated effectively by the proposed method. Beers law is obeyed in the concentration ranges of 0-1.0mg/L for palladium, the molar absorption coefficient is 6.44×104Lmol-1cm-1. The method is applied to the determination of palladium in general ores and palladium catalysts.

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.

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