scholarly journals Studies on complex formation between curcumin and Hg(II) ion by spectrophotometric method: A new approach to overcome peak overlap

2009 ◽  
Vol 7 (3) ◽  
pp. 388-394 ◽  
Author(s):  
Ratanasuda Waranyoupalin ◽  
Sumpun Wongnawa ◽  
Malinee Wongnawa ◽  
Chaveng Pakawatchai ◽  
Pharkphoom Panichayupakaranant ◽  
...  
Keyword(s):  
Complex Formation ◽  
Spectrophotometric Method ◽  
Equilibrium Concentration ◽  
Chloride Ions ◽  
Tetrahedral Complex ◽  
Microsoft Excel ◽  
New Approach ◽  
Peak Overlap ◽  
Linear Plot

AbstractComplex formation between curcumin and Hg(II) ion MeOH/H2O (1: 1 v/v) was investigated and monitored by the spectrophotometric method. The absorption peak of unreacted curcumin which was close and overlapped with that of the complex, was removed by calculation using Microsoft Excel, thereby, allowing determination of the stoichiometry of the complex by the mole-ratio and the Job’s continuous variation methods. Both methods indicated that a 1:1 complex of curcumin and Hg(II) was formed in solution. The formation constant of the 1:1 Hg(II) complex was obtained from two methods, the equilibrium concentration calculation and the linear plot of Benesi-Hildebrand equation, as log K = 4.44 ± 0.16 and 4.83 ± 0.02, respectively. The structure is proposed as a tetrahedral complex of Hg(II) with one curcumin and two chloride ions as ligands.

scholarly journals INTERACTION OF CIS-Pd(NH3)2Cl2 WITH DIPHOSPHONIC ACIDS IN SOLUTIONS AT PHYSIOLOGICAL CHLORIDE-IONS CONCENTRATION

2019 ◽  
Vol 85 (11) ◽  
pp. 3-14
Author(s):  
Oleksandra Kozachkova ◽  
Nataliia Tsaryk ◽  
Vasyl Pekhnyo
Keyword(s):  
Complex Formation ◽  
Equilibrium Concentration ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Acidic Ph ◽  
Bidentate Coordination ◽  
Aqua Complexes ◽  
Diphosphonic Acids ◽  
Ph Range ◽  
Oxygen Atoms

The complex formation of cis-Pd(NH3)2Cl2 with 1-hydroxyethylidene-1,1-diphosphonic (HEDP, H4L1), 3-amino-1-hydroxypropylidene-1,1-diphosphonic (AHPrDP, H4L2), and 1-aminopropylidene-1,1-diphosphonic (APrDP, H4L3) acids in aqueous solutions with the concentration CKCl=0.15 mol/L, which corresponds to the concentration of chloride ions in the intercellular fluid, has been studied by spectrophotometry and pH potentiometry. The results of studying the interaction between cis-Pd(NH3)2Cl2 and diphosphonic acids have been interpreted taking into account the equilibrium concentration distribution of complexes forming in Pd(NH3)2Cl2 solutions at a chloride ion concentration of 0.15 mol/L. It has been found that when Pd(NH3)2Cl2 is dissolved in 0.15 mol/L KCl, ammonia molecules are substituted by chloride ions and a water molecule in the pH range of 2 – 4 to form chloro-aqua complexes [PdCl4]2- and [PdCl3(H2O)]-. In the case of complex formation of Pd(II) chloro-aqua complexes with HEDP and AHPrDP, complexes with [Pd 2OPO3 2Cl] chromophore with bidentate coordination of ligands by two oxygen atoms of phosphonic groups are formed in the acidic pH range. At pH>5, a [Pd(L1)(NH3)2]2- complex (lgβ=30.55(5)) is formed in the cis-Pd(NH3)2Cl2:HEDP=1:1 system, and at pH>6, a [Pd(HL2)(NH3)2]- complex (lgβ=40.29(2)) is formed in the cis-Pd(NH3)2Cl2:AHPrDP=1:1 system. The formation of complexes with [Pd 2OPO3 2Namine] chromophore takes place with the displacement of chloride ions from the coordination sphere of complexes with [Pd 2OPO3 2Cl] chromophore by ammonia molecules. In the system cis-Pd(NH3)2Cl2:APrDP=1:1, the ligand is coordinated to Pd(II) in a bidentate fashion by the nitrogen atoms of the amine group and oxygen atoms of the phosphonic group to form a [Pd(H2L3)Cl2]2- complex with [Pd Namine OPO3 2Cl] chromophore in the acidic pH range. When pH is increased to 5 and then to 7, a sequential substitution of chloride ions by ammonia molecules takes place to form a [Pd(HL3)(NH3)Cl]2- complex (lgβ=38,84(4)) with [Pd 2Namine OPO3 Cl] chromophore and a [Pd(HL3)(NH3)2]- complex (lgβ=43,14(2)) and [Pd(L3)(NH3)2]2- complex (lgβ=34.91(2)) with [Pd 3Namine OPO3] chromophore.

scholarly journals Spectrophotometric Determination of Palladium(II) Ions Using a New Reagent: 4-(N’-(4-Imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic Acid (p-ITYBA)

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Oleksandr S. Tymoshuk ◽  
Orest S. Fedyshyn ◽  
Lesia V. Oleksiv ◽  
Petro V. Rydchuk ◽  
Vasyl S. Matiychuk
Keyword(s):  
Detection Limit ◽  
Complex Formation ◽  
Benzoic Acid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Water Medium ◽  
Analytical Reagent ◽  
Optimal Ph

The simple, rapid spectrophotometric method for palladium(II) ions determination using a new analytical reagent is described. The interaction of Pd(II) ions with a reagent, of the class of azolidones, 4-(N′-(4-imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic acid, in water medium results in the formation of a complex. The Pd(II)-p-ITYBA complex shows maximum absorbance at a wavelength of 450 nm. The molar absorptivity is 4.30 × 103 L·mol−1·cm−1. The optimal pH for complex formation is 7.0. The developed method has a wide linearity range of 0.64–10.64 µg·mL−1 for Pd(II). The detection limit is 0.23 µg·mL−1. It was found that Co(II), Ni(II), Zn(II), Fe(III), Cu(II), Al(III), and many anions do not interfere with the Pd(II) determination. The proposed method was tested in the analysis of model solutions and successfully applied for the determination of palladium in catalyst. The obtained results show that this method can be used for serial determinations of palladium in various objects.

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 A new approach for the determination of sunscreen levels in seawater by ultraviolet absorption spectrophotometry

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243591
Author(s):  
Antonio Tovar-Sánchez ◽  
Erica Sparaventi ◽  
Amandine Gaudron ◽  
Araceli Rodríguez-Romero
Keyword(s):  
Marine Environment ◽  
Spectrophotometric Method ◽  
Analytical Methods ◽  
Low Cost ◽  
Sample Pretreatment ◽  
New Approach ◽  
Spectrophotometric Procedure ◽  
Marine Life ◽  
Absorption Spectrophotometry

Sunscreen is released into the marine environment and is considered toxic for marine life. The current analytical methods for the quantification of sunscreen are mostly specific to individual chemical ingredients and based on complex analytical and instrumental techniques. A simple, selective, rapid, reproducible and low-cost spectrophotometric procedure for the quantification of commercial sunscreen in seawater is described here. The method is based on the inherent properties of these cosmetics to absorb in the wavelength of 300–400 nm. The absorption at 303 nm wavelength correlates with the concentration of most commercial sunscreens. This method allows the determination of sunscreens in the range of 2.5–1500 mg L-1, it requires no sample pretreatment and offers a precision of up to 0.2%. The spectrophotometric method was applied to quantify sunscreen concentrations at an Atlantic Beach with values ranging from 10 to 96.7 mg L-1 in the unfiltered fraction and from the undetectable value to 75.7 mg L-1 in the dissolved fraction. This method is suggested as a tool for sunscreen quantifications in environmental investigations and monitoring programs.

scholarly journals Spectrophotometric Determination of Ezetimibe

2010 ◽  
Vol 7 (1) ◽  
pp. 101-104 ◽  
Author(s):  
P. Baby Sudha Lakshmi ◽  
D. Ramchandran ◽  
C. Rambabu
Keyword(s):  
Complex Formation ◽  
Spectrophotometric Determination ◽  
Ferric Chloride ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Complex Formation Reaction ◽  
Formation Reaction ◽  
Bulk Drug

Two simple, sensitive, selective and accurate spectro-photometric methods (Method A and Method B) for the determination of eztimibe in bulk drug and pharmaceutical formulations (tablets) have been described. Method A and B are based on the redox/complex formation reaction of drug with 1,10-phenanthroline and hexacyano-ferrate(III) in presence of ferric chloride to form coloured chromogens exhibitingλmaxat 510 and 740 nm respectively. The results of analysis for the two methods have been validated statistically and by recovery studies. The results are compared with those obtained using UV spectrophotometric method in alcohol at 231.7 nm.

scholarly journals Spectrophotometric Determination of Some Non-Sedating Antihistamines Using Erythrosine B

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Michael E. El-Kommos ◽  
Samia M. El-Gizawy ◽  
Noha N. Atia ◽  
Noha M. Hosny
Keyword(s):  
Solvent Extraction ◽  
Complex Formation ◽  
Spectrophotometric Method ◽  
Dosage Forms ◽  
Ion Pair ◽  
Pharmaceutical Dosage Forms ◽  
Erythrosine B ◽  
Ich Guidelines ◽  
Sensitive Spectrophotometric Method

A simple and sensitive spectrophotometric method has been developed for the determination of cetirizine (I), ebastine (II), fexofenadine (III), ketotifen (IV), and loratadine (V) based on ion-pair complex formation with erythrosine B. The pink color of the produced complex was measured at 550 nm without solvent extraction. Appropriate conditions were established by studying the color reaction between erythrosine B and the studied drugs to obtain the maximum sensitivity. Beer-Lambert's law is obeyed in the concentration ranges 1–7, 1–8, and 1–6 g/mL for (I, IV), (II, III), and (V), respectively. The method was validated according to ICH guidelines. The suggested method is applicable for the determination of the five investigated drugs in bulk and pharmaceutical dosage forms with excellent recoveries.

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