Photometric determination of 2-oxoglutaric acid and some other 2-oxo acids by reaction with 3-methyl-2-benzothiazolinone hydrazone

1984 ◽  
Vol 49 (8) ◽  
pp. 1869-1880 ◽  
Author(s):  
Jiří Šafanda ◽  
Pavel Sobotka
Keyword(s):  
Glutamic Acid ◽  
High Sensitivity ◽  
Photometric Determination ◽  
Acid Solutions ◽  
Yellow Colour

2-Oxoglutaric acid reacts with 3-methyl-2-benzothiazoline hydrazone in acid solutions in the presence of FeCl3 to give a stady yellow colour. The method enables the substance to be determined in concentrations as low as 15 μmol l-1 with an accuracy of about 10%. The analysis can be performed in the presence of some additional natural or synthetic 2-oxo acids. The applicability of the method was tested in the determination of the activity of some enzymes involved in the metabolism of 2-oxoglutaric acid. Glutamic acid can be determined after its prior nonenzymatic transamination. A number of 2-oxo acids including 2-oxoglutaric acid can be determined photometrically with a high sensitivity by reaction with 3-methyl-2-benzothiazolinone hydrazone in conditions favouring the formation of blue tetra-aza-pentamethinecyanine dyes. The molar absorptivities largely lay within the region of (2-4.5) . 104 l mol-1cm-1.

PHOTOMETRIC DETERMINATION OF TOTAL PHOSPHORUS IN CERTAIN FOOD PRODUCTS

2020 ◽  
Vol 6 (6(75)) ◽  
pp. 54-57
Author(s):  
T.F. Rudometkina
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Content ◽  
Food Additives ◽  
High Sensitivity ◽  
Photometric Determination ◽  
Reduced Form ◽  
Hydrazine Sulfate ◽  
Instant Coffee ◽  
Total Phosphorus Content

A method for determining the total phosphorus content in foods containing food additives of pyrophosphates and polyphosphates (E 450, E339, E452) is proposed. The reaction of formation of a reduced form of phosphormolybdenum heteropolyacid was used. As a reducing agent, a solution of hydrazine sulfate was used as a reagent that provides high sensitivity of determination . The objects of analysis were: chicken meat Roll "Snezana", processed Cheese "Cheeseburger", Instant coffee "Nescafe Gold Crema," containing food additives of pyrophosphates and polyphosphates (E 450,E339, E452). The correctness of the obtained results was confirmed by the method of additives.

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.

Development of a high sensitivity photometric procedure for the determination of vanadium in mineral and fresh waters employing a downsized multicommuted flow analysis approach

2014 ◽  
Vol 6 (24) ◽  
pp. 9667-9674 ◽  
Author(s):  
Tuanne R. Dias ◽  
Jarbas J. R. Rohwedder ◽  
Marcos A. S. Brasil ◽  
Boaventura F. Reis
Keyword(s):  
Analytical Procedure ◽  
Flow Analysis ◽  
High Sensitivity ◽  
Photometric Determination ◽  
Mineral Waters ◽  
Analysis Approach ◽  
Fresh Waters

This article focuses on the development of an analytical procedure for the photometric determination of vanadium in fresh and mineral waters, implemented employing a downsized multicommuted flow analysis approach.

Spectrophotometric study of the reaction of alizarin green series dyes with uranyl ions in the presence of cationoid surfactants

1985 ◽  
Vol 50 (3) ◽  
pp. 611-620 ◽  
Author(s):  
Jiří Šimek ◽  
Nguyen Truong Son ◽  
Eduard Ružička
Keyword(s):  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Acid Solutions ◽  
Uranyl Ions ◽  
Cetylpyridinium Bromide ◽  
Weakly Acid ◽  
Coordination Properties

The coordination properties of alizarin green series dyes with uranyl ions were studied in the presence of cationoid surfactants (cetylpyridinium bromide, carbethoxypentadecyltrimethylammonium bromide). Ternary complexes of the composition UO2L2S2, UO2L2S4, UO2L2S6, and UO2L3S9, where L is dye and S is surfactant, are formed in weakly acid solutions. The formation constants of the complexes were established and a procedure was worked out for the direct photometric determination of uranium.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

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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