Complex equilibria and spectrophotometric determination of copper with 4-(2-pyridylazo)resorcinol and 4-(2-thiazolylazo)resorcinol

1980 ◽  
Vol 45 (5) ◽  
pp. 1502-1524 ◽  
Author(s):  
Aleš Hrdlička ◽  
Marie Langová
Keyword(s):  
Spectrophotometric Determination ◽  
Bathochromic Shift ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Numerical Treatment ◽  
Weakly Alkaline ◽  
Complex Equilibria ◽  
Absorbance Data ◽  
Determination Of Copper

The complex equilibria of copper with 4-(2-pyridylazo)resorcinol and 4-(2-thiazolylazo)resorcinol were studied spectrophotometrically using graphical analysis and numerical treatment of the absorbance data by the PRCEK or SPEKTFOT program on a Tesla 200 computer. Of the two reagents, 4-(2-pyridylazo)resorcinol forms more complexes including the 1 : 2 complexes, with a greater bathochromic shift of λmax with respect to the reagent. Especially the CuL2-2 complex of 4-(2-pyridylazo)resorcinol with ε = 7.9 . 104 at 500 nm permits sensitive spectrophotometric determination of copper. Procedures for the spectrophotometric determination of copper in weakly alkaline media were evaluated.

The reactions of gallium, indium and thallium with 2-(2-pyridylazo)-1-naphthol-4-sulphonic acid and their spectrophotometric determination

1980 ◽  
Vol 45 (1) ◽  
pp. 54-79 ◽  
Author(s):  
Petr Voznica ◽  
Josef Havel ◽  
Lumír Sommer
Keyword(s):  
Reaction Mechanism ◽  
Spectrophotometric Determination ◽  
Graphical Analysis ◽  
Sulphonic Acid ◽  
Complete Picture ◽  
Optimum Conditions ◽  
Complex Equilibria ◽  
Absorbance Data

The complex equilibria of gallium, indium and thallium(III) with analytically important 2-(2-pyridylazo)-1-naphthol-4-sulphonate were studied spectrophotometrically using graphical analysis of the absorbance curves and minimization procedures for the absorbance data using the SPEKTFOT program on the Tesla 200 computer. The study yielded a complete picture of the reaction mechanism of these elements with heterocyclic azodyes. Optimum conditions for the spectrophotometric determination of gallium, indium and thallium using this reagent were found.

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.).

Optimization of an analytical method for the spectrophotometric determination of copper in tea and water samples after ultrasonic assisted cloud point extraction using a benzothiazole fluorescein derivative complexing agent

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65321-65327 ◽  
Author(s):  
Chunlei Fan ◽  
Shengxu Luo ◽  
Rong Liu
Keyword(s):  
Cloud Point ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
Analytical Method ◽  
Cloud Point Extraction ◽  
Complexing Agent ◽  
Ultrasonic Assisted ◽  
Determination Of Copper

BTF is exists with spirolactone species with adding Cu2+, which leads to the absorbance intensity is decreased gradually and the decrease of the absorbance value is linear for Cu2+.

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