Spectrophotometric study of the complex equilibria of cadmium(II) ions with 4-(2-pyridylazo)resorcine (PAR) using the SQUAD-G program and the method of determining Cd(II) ions with PAR

1982 ◽  
Vol 47 (4) ◽  
pp. 1086-1099 ◽  
Author(s):  
Sylva Vlčková ◽  
Luděk Jančář ◽  
Vlastimil Kubáň ◽  
Josef Havel
Keyword(s):  
Aqueous Solutions ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Linear Part ◽  
Spectrophotometric Study ◽  
Statistical Parameters ◽  
Cadmium Ions ◽  
Graphical Interpretation ◽  
Basic Parameters ◽  
The Individual

The existence of the red-orange CdLH+ complex (λmax = 406 nm, εmax = 1.78.104 mmol-1.cm2, log *β111 = -1.66+0.04) and CdL complex (λmax = 495 nm, εmax = 3.2.104 mmol-1. cm2, log *β112 = -8.25+0.05) was demonstrated in aqueous solutions of PAR with a concentration excess of Cd(II) ions. It was shown that a 10% v/v acetone medium containing Cd(II) in a concentration excess of PAR contains the following complexes: CdL2H2 (λmax = 507 nm, εmax = 1.4 . 104 mmol-1 cm(2), log*β122 = -2.85+0.04), CdL2H- (λmax = 495 nm, εmax = 6.25 . 104 mmol-1 cm2, log *β123 = -9.58 + 0.04) and CdL2-2 (λmax = 495 nm, εmax = 9.16 . 104 mmol-1 cm2, log *β124 = -17.33 + 0.06). The basic parameters of the individual complexes were determined by graphical interpretation using slope-intercept transformations and by numerical interpretation using the generalized SQUAD-G program. The statistical parameters of the spectrophotometric method of determining cadmium ions were evaluated from the linear part of the calibration curve using the STAT program.

scholarly journals Spectrophotometric Study of ?-Irradiated PM-355

2009 ◽  
Vol 6 (3) ◽  
pp. 584-589
Author(s):  
Baghdad Science Journal
Keyword(s):  
Absorption Spectra ◽  
Calibration Curve ◽  
Linear Relation ◽  
Response Curve ◽  
Energy Gap ◽  
Linear Part ◽  
Absorbed Dose ◽  
Spectrophotometric Study ◽  
High Dose ◽  
Radiation Induced

The aim of the present work is concerned with the effect of ?-irradiation on PM-355 with absorbed dose of (30-160Mrad) range. This polymer is evaluated spectrophotometrically for use as high dose dosimeters. The absorption spectra of irradiated samples showed radiation induced absorption changes. There is an increment in absorption proportional with absorbed dose. This increment is attributed to interfaces traps which, are formed by irradiation. Calibration curve was drawn .The linear relation was found in calibration curve, and dosimeter range was determined from the linear part. The linearity in response curve suggested that PM-355 could be used as dosimeter within (30-160Mrad) rang. Energy gap shift was used as a second tool to determine the dosimeter range. It was found that PM-355 energy gap systematically decreasing with absorbed dose, and it could be used as a second tool to determine the dosimeter range.

scholarly journals A New Spectrophotometric Method for Analysis of Allopurinol in Aqueous Solutions and Pharmaceutical Preparations

2009 ◽  
Vol 6 (2) ◽  
pp. 309-314
Author(s):  
Baghdad Science Journal
Keyword(s):  
Absorption Spectrum ◽  
Aqueous Solutions ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Good Stability ◽  
Optimum Conditions ◽  
Wide Range

A new method for determination of allopurinol in microgram level depending on its ability to reduce the yellow absorption spectrum of (I-3) at maximum wavelength ( ?max 350nm) . The optimum conditions such as "concentration of reactant materials , time of sitting and order of addition were studied to get a high sensitivity ( ? = 27229 l.mole-1.cm-1) sandal sensitivity : 0.0053 µg cm-2 ,with wide range of calibration curve ( 1 – 9 µg.ml-1 ) good stability (more then24 hr.) and repeatability ( RSD % : 2.1 -2.6 % ) , the Recovery % : ( 98.17 – 100.5 % ) , the Erel % ( 0.50 -1.83 % ) and the interference's of Xanthine , Cystein , Creatinine , Urea and the Glucose in 20 , 40 , 60 fold of analyate were also studied .

Smoothing of stationary random signal in continuous flow mixer with gamma-distribution of residence times

1985 ◽  
Vol 50 (11) ◽  
pp. 2545-2557
Author(s):  
Pavel Hasal ◽  
Vladimír Kudrna ◽  
Jitka Vyhlídková
Keyword(s):  
Theoretical Analysis ◽  
Gamma Distribution ◽  
Continuous Flow ◽  
Random Signal ◽  
Linear Filter ◽  
Residence Times ◽  
Statistical Parameters ◽  
Basic Parameters

The paper is focused on a theoretical analysis of the function of continuous flow mixer with the so-called gamma-distribution of fluid residence times, used as a linear filter smoothing undesirable fluctuations of input properties. A relation is derived expressing the degree of smoothing of the signal passing through the system, as a function of statistical parameters of this signal and of gamma-distribution of fluid-residence times in the mixer. The analysis of this relation leads to conclusions concerning the prediction of the operation of smoothing mixers or the design of their basic parameters.

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

scholarly journals Determination of Sodium Cromoglycate by a New Kinetic Spectrophotometric Method in Biological Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Mohsen Keyvanfard ◽  
Khadijeh Alizad ◽  
Razieh Shakeri
Keyword(s):  
Standard Deviation ◽  
Sodium Cromoglycate ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Micellar Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A new kinetic spectrophotometric method is described for the determination of ultratrace amounts of sodium cromoglycate (SCG). The method based on catalytic action of SCG on the oxidation of amaranth with periodate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the amaranth at 518 nm, for the first 4 min from initiation of the reaction. Calibration curve was linear in the range of 4.0−36.0 ng mL−1SCG. The limit of detection is 2.7 ng mL−1SCG. The relative standard deviation (RSD) for ten replicate analyses of 12, 20, and 28 ng mL−1SCG was 0.40%, 0.32%, and 0.53%, respectively. The proposed method was used for the determination of SCG in biological samples.

scholarly journals Inhomogeneities in PNIPAM Aqueous Solutions: The Inside View by Spin Probe EPR Spectroscopy

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3829
Author(s):  
Ekaterina M. Zubanova ◽  
Sergei V. Kostjuk ◽  
Peter S. Timashev ◽  
Yury A. Rochev ◽  
Alexander I. Kokorin ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Coming Out ◽  
Epr Spectroscopy ◽  
Spin Probe ◽  
Guest Molecule ◽  
Continuous Wave ◽  
Paramagnetic Resonance ◽  
Molten Globules ◽  
The Individual ◽  
Tempo Radical

Coil to globule transition in poly(N-isopropylacrylamide) aqueous solutions was studied using spin probe continuous-wave electronic paramagnetic resonance (CW EPR) spectroscopy with an amphiphilic TEMPO radical as a guest molecule. Using Cu(II) ions as the “quencher” for fast-moving radicals in the liquid phase allowed obtaining the individual spectra of TEMPO radicals in polymer globule and observing inhomogeneities in solutions before globule collapsing. EPR spectra simulations confirm the formation of molten globules at the first step with further collapsing and water molecules coming out of the globule, making it denser.

scholarly journals Spectrophotometric investigation of the Fe(III)-disulphonate hydroquinone complex

2005 ◽  
Vol 70 (4) ◽  
pp. 651-659
Author(s):  
Mirjana Obradovic ◽  
Snezana Mitic ◽  
Snezana Tosic ◽  
A.N. Pavlovic
Keyword(s):  
Stability Constant ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Relative Stability ◽  
Time Stability ◽  
Acid Media ◽  
Influence Of Temperature ◽  
Complex Dependence ◽  
Indigo Blue

Iron(III) form an indigo-blue complex with the disulphonated product of hydroquinone (K2S2Hy) in acid media with an absorption maxima at 600 nm. The time stability of the complex, dependence of the complex absorbance on pH and the influence of temperature and solvent were followed on the basis of spectrophotometric measurements. Using the Job, mole ratio and Henry?Franck?Ostwald methods, the composition and relative stability constant of this complex, in 80 vol.% ethanol as solvent, were determined (1:1;log??293 = 3.37). A new spectrophotometric method for the determination of iron has been developed and the calibration curve is linear in the concentration range from0.65 to 6.45 ?g cm-3. The effects of foreign ions on the determination of iron were investigated in order to assess the selectivity of the method. The method was applied for the determination of Fe(III) in the natural juice of beet.

Spectrophotometric study of the complexation reactions between alkaline earth cations and murexide in some non-aqueous solutions

Polyhedron ◽  
1988 ◽  
Vol 7 (14) ◽  
pp. 1227-1230 ◽  
Author(s):  
Soheila Kashanian ◽  
Mohammad Bagher Gholivand ◽  
Siavash Madaeni ◽  
Alireza Nikrahi ◽  
Mojtaba Shamsipur
Keyword(s):  
Aqueous Solutions ◽  
Alkaline Earth ◽  
Spectrophotometric Study ◽  
Complexation Reactions ◽  
Alkaline Earth Cations
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