Application of the Generalized Molar-Ratio Method to the Determination of the Stoichiometry and Apparent Binding Constant of Nanoparticle-Organic Capping Systems

2015 ◽  
Vol 27 (10) ◽  
pp. 2302-2312 ◽  
Author(s):  
Antonio Doménech-Carbó ◽  
María González-Béjar ◽  
Julia Pérez-Prieto
Keyword(s):  
Binding Constant ◽  
Molar Ratio ◽  
Ratio Method ◽  
Apparent Binding Constant ◽  
Molar Ratio Method ◽  
Organic Capping

scholarly journals Spectrophotometric Determination of Selenium in Various Samples Using 5,6-Diaminouracil Hydrochloride (DAUH)

2015 ◽  
Vol 61 ◽  
pp. 128-136 ◽  
Author(s):  
Salwa Fares Rassi
Keyword(s):  
Acidic Medium ◽  
Metal Ion ◽  
Molar Absorptivity ◽  
Molar Ratio ◽  
Ratio Method ◽  
Colored Complex ◽  
Molar Ratio Method ◽  
Analytical Reagent ◽  
Color Reactions

A simple, rapid and sensitive spectrophotometric method was developed for the determination of Se (IV) using 5,6-diaminouracil hydrochloride (DAUH) as an analytical reagent. The reagent has been synthesized and characterized using IR, 1H NMR. The metal ion in aqueous medium forms yellow colored complex with DAUH showing maximum absorbance at 343 nm. Hence, analytical studies were further carried out at 343 nm. The reagent reacts with selenium in acidic medium to form yellow colored 1:1 (M:L) complex . The color reactions are instantaneous and absorbance values remain constant for one week. The composition of the Se (IV) complex with DAUH was studied by the method of job’s continuous variation and molar ratio method. Beer’s law was obeyed in the range 0.2-15.0 μg mL−1of Se (IV). The molar absorptivity and Sandell’s sensitivity of the method were found to be 0.5×10+4 L.mol-1.cm-1and 0.031μg.cm-2 respectively. Since DAUH method is more sensitive, it was applied for the determination of selenium in samples.

scholarly journals Biological Study of Transition Metal Complexes with Adenine Ligand

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 77 ◽  
Author(s):  
Hamad M. I. Hasan ◽  
Aaza I. Yahiya ◽  
Safaa S. Hassan ◽  
Mabrouk M. Salama
Keyword(s):  
Metal Complexes ◽  
Molar Conductance ◽  
Molar Ratio ◽  
Biological Study ◽  
Ratio Method ◽  
Spectroscopic Techniques ◽  
Stoichiometric Ratio ◽  
Metal Contents ◽  
Molar Ratio Method

Adenine complexes were prepared with some of the first series transition metals in a stoichiometric ratio of 1: 2 (Mn+: L), where Mn+ = Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ ions. The Complexes were characterized by the physicochemical and spectroscopic techniques as electric conductivity, metal contents, IR, UV–Visible, and molar conductance techniques. The stoichiometric ratios of the synthesized complexes were confirmed by using molar ratio method. The dissociation constant of adenine ligand was determined spectrophotometrically. Solvent effect on the electronic spectra of the adenine ligand was examined using solvents with different polarities. The biological activity of adenine ligand and its metal complexes were tested in vitro against some selected species of fungi and bacteria. The results showed a satisfactory spectrum against the tested organisms.

Spectrophotometric Determination of Copper (II) with 5-Hydroxy-6-Mercapto-Benzo [a] Phenazine

2008 ◽  
Vol 59 (1) ◽  
pp. 3-7
Author(s):  
Aurora Reiss ◽  
Mihaela Mureseanu ◽  
Nicolae Muresan
Keyword(s):  
Spectrophotometric Determination ◽  
Molar Absorptivity ◽  
Molar Ratio ◽  
Variation Method ◽  
Ratio Method ◽  
Relative Standard ◽  
Analytical Reagent ◽  
Experimental Values ◽  
Determination Of Copper

5-Hydroxy-6-mercapto-benzo [a] phenazine (HMBP) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of copper (II). Copper reacts with HMBP to give a dark red complex which is soluble in chloroform. The composition of the CuII � HMBP complex is established as 1:2 by Job�s continuous variation method and molar ratio method. The instability constant of the complex calculated by Job�s relation for nonisomolar series is 4.65 . 10-9, at room temperature. The CuII-HMBP complex in chlorophorm shows a maximum absorbance at 495 nm, with molar absorptivity and Sandell�s sensitivity values of 7.39 . 103dm3 mol-1 cm-1 and 0.012 mg cm-2, respectively. Beer�s law is obeyed in the concentration range 0.67 - 26.90 mg mL-1 and the detection limit is 0.59 mg mL-1. A repetition of the method is checked by finding the relative standard deviation (RSD) at 1.00 mg mL-1 CuII of 0.6%. The method is successfully employed for the determination of copper (II) in environmental samples. The reliability of the method is assured by analysing the standard alloys and by inter-comparison of experimental values, using an atomic absorption spectrometer.

Estimation of diet in extinct raccoon dog species by the molar ratio method

2016 ◽  
Vol 98 (3) ◽  
pp. 292-299 ◽  
Author(s):  
Masakazu Asahara ◽  
Masanaru Takai
Keyword(s):  
Molar Ratio ◽  
Ratio Method ◽  
Raccoon Dog ◽  
Molar Ratio Method

scholarly journals Reversible Oxygenation of 2,4-Diaminobutanoic Acid-Co(II) Complexes

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Cheng ◽  
Yan Huang ◽  
Hui Li ◽  
Fan Yue ◽  
Hongmei Wen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Oxygen Carrier ◽  
Molar Ratio ◽  
Ratio Method ◽  
Oxygen Carriers ◽  
Structural Detail ◽  
New Family ◽  
Molar Ratio Method ◽  
The Relationship ◽  
Insight Into

This paper introduces the structural characterization and studies on reversible oxygenation behavior of a new oxygen carrier Co(II)-2,4-diaminobutanoic acid (DABA) complex in aqueous solution. The composition of the oxygenated complex was determined by gas volumetric method, molar ratio method, and mass spectrometry, and the formula of the oxygenated complex was determined to be [Co(DABA)2O2]. In aqueous solution, the complex can continuously uptake and release dioxygen and exhibit excellent reversibility of oxygenation and deoxygenation ability. This complex can maintain 50% of its original oxygenation capacity after 30 cycles in 24 h and retain 5% of the original oxygenation capacity after more than 260 cycles after 72 h. When a ligand analogue was linked to histidine (His), the new complex exhibited as excellent reversible oxygenation property as His-Co(II) complex. Insight into the relationship between structural detail and oxygenation properties will provide valuable suggestion for a new family of oxygen carriers.

scholarly journals Synthesis, spectroscopic study of Pt (IV), Au (III), Rh(III),Co(II) and V (IV) complexes with sodium[5-(p-nitro phenyl) -/4- phenyl-1,2,4-triazole-3-dithiocarbamato hydrazide] and cytotoxicity assay on rhabdomyosarcoma cell line of heavy metals

2012 ◽  
Vol 9 (4) ◽  
pp. 668-679 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Cell Line ◽  
Molar Absorptivity ◽  
Molar Ratio ◽  
Ratio Method ◽  
Ethanolic Solution ◽  
Flame Atomic Absorption ◽  
Square Planar ◽  
Vis Spectroscopy ◽  
Molar Ratio Method ◽  
Ft Ir

All the prepared metal complexes of Pt (IV), Au(III), Rh (III), Co (II) and V(IV) with new ligand sodium [5-(p-nitro phenyl)-/4-phenyl-1,2,4-triazole-3-dithiocarbamato hydrazide] (TRZ.DTC) have been synthesized and characterized in solid state by using flame atomic absorption, elemental analysis C.H.N.S, FT-IR ,UV-Vis Spectroscopy, conductivity and magnetic susceptibility measurements. The nature of the complexes formed in ethanolic solution has been studied following the molar ratio method also was studied stability constant and found to be stable in molar ratio1:1 of VL (IV) and CoL(II) while Pt(IV), Au(III) and Rh(III) complexes stable in molar ratio 1:2 as well as the molar absorptivity for these complexes were calculated. From the previous analyses, octahedral geometry was suggested for Pt (IV), Rh (III) and Co (II) complexes, square planar was suggested for Au(III) complex while V(IV) complex has a square pyramidal. Cytotoxic effect of PtL, AuL and RhL as well as ligand has been evaluated against RD cell line by using four different concentrations (500, 250, 125 & 62.5 µg/ml) respectively in three exposure times 24, 48 and 72 hrs and compared this effect with control positive Cis-Pt.

scholarly journals Spectrophotometric Determination of Cu(II) in Analytical Sample Using a New Chromogenic Reagent (HPEDN)

2020 ◽  
Vol 20 (5) ◽  
pp. 1080
Author(s):  
Esraa Raafid ◽  
Muneer A. Al-Da’amy ◽  
Salih Hadi Kadhim
Keyword(s):  
Schiff Base ◽  
Absorption Spectrometry ◽  
Molar Ratio ◽  
Ratio Method ◽  
Chromogenic Reagent ◽  
Flame Atomic Absorption ◽  
Vis Spectroscopy ◽  
Masking Agents ◽  
Good Agreement

The sensitive, accurate and rapid spectrophotometric method that can be used for determination of Cu(II) in the analytical samples using a new chromogenic reagent azo-Schiff base 1-((4-(1-(2-hydroxyphenylimino)ethyl)-phenyl)diazenyl) naphthalene-2-ol (HPEDN). The synthesized new (azo-Schiff base) ligand was complexed with copper(II) and characterized using UV/Vis spectroscopy, IR spectra, 1H-NMR, 13CN-MR spectra, Molar electrical connectivity, and measuring of their melting points. Then obtained complex showed a brown color with maximum absorption at λmax = 500 nm at pH = 9. Beer’s law is obeyed in the concentration in the range of 1.7 to 5.4 μg/mL. The molar absorption and Sandell’s sensitivity values of Cu(II) complex were found to be 0.5038 × 104 L mol–1 cm–1 and 0.0039 μg cm–2, respectively. Structure of the prepared complex was investigated by using the continuous variation, mole ratio method and slope analysis method. The obtained results showed that the complex has (1:2) (M:L) molar ratio and these results showed that this method were more sensitive, more precise and accuracy through the calculation of (Re, Erel, R.S.D)%. The most important interferences were due to, Co2+, Cd2+, Zn2+, Ni2+, Mn2+, Pd2+, Fe3+ and these were studied, and suitable masking agents were used. This method was applied for the determination of Cu(II) in alloy. The obtained results were compared with flame atomic absorption spectrometry method and these results were in a good agreement in these two cases.

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