Reactions of gallocyanine methyl ester with vanadates and molybdates

1980 ◽  
Vol 45 (12) ◽  
pp. 3302-3312
Author(s):  
Milan Kotouček ◽  
Marie Barešová ◽  
Nguyen Truong Son
Keyword(s):  
Methyl Ester ◽  
Equilibrium Constants ◽  
Photometric Determination ◽  
Acidic Solutions ◽  
Concentration Curves

Reactions of gallocyanine methyl ester with vanadates and molybdates were examined spectrophotometrically in weakly acidic solutions in 10% (m/m) ethanol. Vanadates form the VO2L2, VO2(OH)L, and VO3L complexes at pH 3-6.5, molybdates form the MoO2L2 and MoO3L complexes at pH 1.5-4.4 and pH 3-5.3, respectively. The equilibrium constants of the systems concerned were calculated from the data of the concentration curves. Use has been made of the formation of the MoO2L2 complex for photometric determination of molybdenum.

Reactions of gallocyanine methyl ester with gallium(III) and indium(III) ions

1982 ◽  
Vol 47 (7) ◽  
pp. 1950-1963 ◽  
Author(s):  
Milan Kotouček ◽  
Josef Růžička ◽  
Pavla Vaculíková
Keyword(s):  
Methyl Ester ◽  
Stability Constants ◽  
Equilibrium Constants ◽  
Photometric Determination ◽  
Conditional Stability ◽  
Conditional Stability Constants

Reactions of gallocyanine methyl ester with gallium(III) and indium(III) ions in solutions in 15% (m/m) ethanol were studied spectrophotometrically. At pH 1.7-6.5, the GaL, GaL2, and Ga(OH)L3 complexes are formed; in the case of indium, the In(OH)2L2 and In(OH)L3 complexes appear at pH 4-6.5, and InL3B2 in tartrate solutions. The conditional stability constants and the equilibrium constants of the coordination equilibria were calculated, and procedures were worked out for a photometric determination of gallium and for a chelatometric determination of gallium and indium using gallocyanine methyl ester as metallochromic indicator.

Reactions of gallocyanine methyl ester with germanium(IV), tin(IV) and lead(II) ions

1984 ◽  
Vol 49 (9) ◽  
pp. 2078-2095
Author(s):  
Milan Kotouček ◽  
Josef Růžička
Keyword(s):  
Methyl Orange ◽  
Methyl Ester ◽  
Equilibrium Constants ◽  
Colour Change ◽  
Photometric Determination ◽  
Conditional Stability ◽  
Acid Solutions ◽  
Complexation Reactions ◽  
Conditional Stability Constants

The reactions of gallocyanine methyl ester with germanium(IV) and tin(IV) in 7.7% (m/m) ethanol and with lead(II) in 15.5% ethanol are studied spectrophotometrically. In slightly acid solutions, complexes of GeL3 (pH 2.5-6.5), SnL2 and SnL3 (pH 1.7-6 in the presence oftartaric acid), and PbL and PbL2 (pH 4-7) are formed. The conditional stability constants of the complexes and the equilibrium constants of the complexation reactions are calculated and procedures are suggested for the photometric determination of tin and for the chelometric determination of lead using visual or photometric indication with gallocyanine methyl ester as metallochromic indicator (colour change from red-violet to blue). A gallocyanine methyl ester-methyl orange screened indicator proved useful for the visual determination of lead, showing an expressive colour change from brown to green.

Reaction of gallocyanine methyl ester with uranyl ions

1984 ◽  
Vol 49 (9) ◽  
pp. 2070-2077
Author(s):  
Milan Kotouček ◽  
Marta Hrbková
Keyword(s):  
Methyl Ester ◽  
Equilibrium Constants ◽  
Conditional Stability ◽  
Uranyl Ions ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Conditional Stability Constants ◽  
Concentration Curves ◽  
Coordination Reaction

The reaction of gallocyanine methyl ester with uranyl ions was studied spectrophotometrically in slightly acid or neutral solutions in 40% (m/m) ethanol. A violet complex of UO2L2 is formed at pH > 5. The conditional stability constants of the complex in the pH 6 - 7.4 range and the equilibrium constants of the coordination reaction were derived from the concentration curves and continuous variations curves. The optimum conditions were sought for the spectrophotometric determination of uranium based on the occurrence of the UO2L2 complex. The relative standard deviation obtained for a uranium concentration of 106 μg l-1 was sr = 2.13%.

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.

Photometric determination of copper (II) microquantities in pyrite

2019 ◽  
Vol 85 (10) ◽  
pp. 23-28
Author(s):  
F. S. Aliyeva ◽  
F. O. Mamedova ◽  
F. N. Bahmanova ◽  
Yu. A. Yusibov ◽  
F. M. Chyragov
Keyword(s):  
Photometric Determination ◽  
Determination Of Copper
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