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.).

Spectrophotometric study of the acid-base and optical properties of the 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-(diethylamino)phenol (BrPADAP, ClPADAP) and their complexation equilibria with zinc(II) ions

1982 ◽  
Vol 47 (10) ◽  
pp. 2676-2691 ◽  
Author(s):  
Miroslav Macka ◽  
Vlastimil Kubáň
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Acid Base ◽  
Ethanol Medium ◽  
Triton X ◽  
Mixed Water ◽  
Derivatives Of

The optical and acid-base characteristics of BrPADAP and ClPADAP were studied in mixed water-ethanol and water-DMF media and in 10% ethanol medium in the presence of cationic, anionic and nonionic tensides. The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the ML and ML2 complexes with zinc(II) ions were found by graphical analysis and numerical interpretation of the absorbance curves by the modified SQUAD-G program. Optimal conditions were found for the spectrophotometric determination of Zn(II) in the presence of 0.1% Triton X-100 or 1% Brij 35 in alkaline media with pH = 6.5-10. BrPADAP and ClPADAP are the most sensitive reagents (ε = 1.3-1.6 . 105 mmol-1 cm2 at 557 and 560 nm, respectively) for the determination of zinc with high colour contrast of the reaction (Δλ = 104 nm) and selectivity similar to that for the other N-heterocyclic azodyes (PAN, PAR, etc.).

scholarly journals Determination of thymol with micellar extraction preconcentration

2021 ◽  
Vol 21 (3) ◽  
pp. 267-273
Author(s):  
Elmira I. Tsygulyova ◽  
◽  
Sergei Yu. Doronin ◽  
Keyword(s):  
Aqueous Media ◽  
Spectrophotometric Study ◽  
Azo Compounds ◽  
Colorimetric Determination ◽  
Optimal Conditions ◽  
Color Channel ◽  
Micellar Extraction ◽  
Triton X ◽  
Extraction Preconcentration

For the efficient preconcentration of azo compounds – products of the interaction of 4-nitrophenyldiazonium with thymol, a system 4-nitroaniline (4-NA) – NO2- – Triton X-100 – NaOH – ethanol has been proposed. The optimal conditions for the formation of micellarsaturated phases of the system under study have been established: 3.10-4 M 4-NA – 3.10-4 M NO2- – 5% Triton X-100 – 2.8 M NaOH – 10 vol. % С 2Н5ОН. A spectrophotometric study of the above system has been carried out. A linear dependence was built in the coordinates A (at λ max = 552 nm) vs с(thymol), which is described by an equation of the form A = f(c), A = 26291c + 0.02; R2 = 0.997. The range of the determined contents of thymol is (2·10-6 – 4·10-5) mol/l. A technique for the colorimetric determination of thymol in aqueous media (color channel G) has been developed. The intensity of the channel G chromaticity (IG) is linearly dependent on pc(thymol) in accordance with the equation IG = 54.2pc – 267, R 2 = 0; the lower limit of the determined contents of thymol is 1.10-6 mol/l, which is two times less than in the variant of its spectrophotometric determination. The profiles of petal diagrams in the color coordinates of the RGB CMYK model have been constructed; the dependences of their area (S) and perimeter (P) on the thymol concentration have been obtained (P: y = 278x – 10.13; R 2 = 0.97; S: y = 20182x – 87649, R 2 = 0.99).

Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides

1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con
Keyword(s):  
Absorption Spectra ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Optimal Conditions ◽  
Bromopyrogallol Red ◽  
Binary Complexes

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.

Detection of peroxyacetyl nitrate in air using chemiluminescence aerosol detector

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Pavel Mikuška ◽  
Lukáš Bružeňák ◽  
Zbyněk Večeřa
Keyword(s):  
Alkaline Solution ◽  
Limit Of Detection ◽  
Packed Column ◽  
Direct Reaction ◽  
Peroxyacetyl Nitrate ◽  
Brij 35 ◽  
Alternative Approach ◽  
Sensitive Determination ◽  
Triton X

AbstractA method for the rapid and sensitive determination of peroxyacetyl nitrate (PAN) in air based on a chemiluminescence reaction with an alkaline solution of luminol in the chemiluminescence aerosol detector is described. The PAN is chromatographically separated from nitrogen dioxide and ozone in a packed column filled with 5 % OV-1 on Chromosorb 30/60 and the eluted PAN is detected via the direct reaction with the luminol solution consisting of 0.002 mol L−1 luminol, 1 vol. % Brij-35 and 0.1 mol L−1 KOH. The limit of detection is 14.9 ng m−3 (3 ppt) of PAN. Alternatively, the PAN after separation is thermally converted to NO2 which is detected by the chemiluminescence reaction with a solution consisting of 0.002 mol L−1 luminol, 0.5 mol L−1 KOH, 0.2 mol L−1 Na2SO3, 0.1 mol L−1 KI, 0.05 mol L−1 EDTA and 0.5 vol. % triton X-100. The alternative approach affords the simultaneous determination of PAN and NO2. The limit of detection is 50 ppt of PAN and 50 ppt of NO2. The time resolution is 3 min. The method was applied to the measurement of ambient peroxyacetyl nitrate in air.

Spectrophotometric study of reaction of sodium 6-hydroxy-5-dibenzo(a,j)phenoxazone-11,13-disulfonate with aluminium ions in the presence of cationoid tensides

1980 ◽  
Vol 45 (4) ◽  
pp. 1227-1235
Author(s):  
Nguyen Truong Son ◽  
Jan Lasovský ◽  
Eduard Ružička
Keyword(s):  
Acidic Medium ◽  
Equilibrium Constants ◽  
Ternary Systems ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Medium Ph ◽  
Binary And Ternary Systems

In weakly acidic medium, pH 3.5-6.5, the title dye forms with aluminium ions a complex with the Al : L ratio 1 : 1. In the presence of cetylpyridinium or carbethoxypentadecyltrimethylammonium, ternary complexes AlL3Sr (r = 6 or 9, respectively) are formed. The equilibrium constants of the complexing equilibria in the binary and ternary systems concerned were calculated, and a method of photometric determination of aluminium has been suggested.

Spectrophotometric study of the reaction of dyes of the alizarin green series with indium(III) ions in the presence of cationic tensides

1980 ◽  
Vol 45 (3) ◽  
pp. 703-714 ◽  
Author(s):  
Nguyen Truong Son ◽  
Eduard Ružička
Keyword(s):  
Equilibrium Constants ◽  
Ternary Systems ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Conditional Stability ◽  
Acid Media ◽  
Weakly Acid ◽  
Cetyl Pyridinium ◽  
Conditional Stability Constants

The reactions of four dyes of the alizarin green series with indium(III) ions were studied. In weakly acid media of pH 4-6.5, binary InL and InL2 complexes are formed in solution. In the presence of cationic tensides containing cetyltrimethylammonium and cetyl pyridinium, defined ternary complexes, InL3S6, are formed in the solution. The conditional stability constants of the binary In-L complexes and the equilibrium constants of the studied complexing ternary systems were calculated and a procedure for the photometric and chelometric determination of indium was proposed.

Spectrophotometric study of complexation equilibria and of a method for the determination of Fe(III) ions with 4-(2-pyridylazo)resorcinol and 4-(2-thiazolylazo)resorcinol

1979 ◽  
Vol 44 (2) ◽  
pp. 374-392 ◽  
Author(s):  
Ellena Russeva ◽  
Vlastimil Kubáň ◽  
Lumír Sommer
Keyword(s):  
Stability Constants ◽  
Spectrophotometric Determination ◽  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Component Concentration ◽  
Optimum Conditions ◽  
Ferric Ions ◽  
Absorption Coefficients ◽  
Basic Parameters

The composition, molar absorption, coefficients, equilibrium constants and stability constants for the MLH, ML, M(LH)2 and ML2 complexes have been determined graphically using slope-intercept transformations and numerically from the absorbance-pH curves and from the absorbance dependence on the component concentration, using the PRCEK III and SPEKTFOT programs, or from the continuous variation plots using the JOBCON program. The optimum conditions were found for a spectrophotometric determination of ferric ions with TAR and PAR reagents in pure solutions. The basic parameters of the analytical curves were evaluated using the STAT program.

A spectrophotometric study of the complexation equilibria and the determination of nickel(II) with 4-(2-pyridylazo)resorcinol, 4-(2-thiazolylazo)resorcinol, and 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol

1987 ◽  
Vol 52 (4) ◽  
pp. 878-912 ◽  
Author(s):  
Marie Langová ◽  
Zdeněk Šimek ◽  
Jitka Chromá ◽  
Lumír Sommer
Keyword(s):  
Drinking Water ◽  
Spectrophotometric Study ◽  
Brij 35 ◽  
Complexation Equilibria ◽  
Determination Of Nickel ◽  
Absorbance Data

The complexation equilibria of Ni(II) with 4-(2-pyridylazo)resorcinol (PAR) and 4-(2-thiazolylazo)resorcinol (TAR) in 30 vol.% ethanol and with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (BrPADAP) in 10 vol.% ethanol containing 0·1% BRIJ-35 tenside were studied spectrophotometrically. The absorbance data were processed by the SPEFO 8, HALTAFALL SPEFO and SQUAD-G programs. The working procedures for the determination of Ni(II) with the reagents in pure solutions were optimized and statistically evaluated, and PAR was applied to the determination of Ni(II) in drinking water.

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