E 70 - 52T Tentative Method for Determination of pH of Aqueous Solutions with the Glass Electrode

2009 ◽  
pp. 588-588-7
Author(s):  
Keyword(s):  
Aqueous Solutions ◽  
Glass Electrode ◽  
Tentative Method

Formation constants for selected organo—metal (Al3+, Fe3+)—phosphate complexes

1985 ◽  
Vol 63 (12) ◽  
pp. 3357-3366 ◽  
Author(s):  
Paul A. Arp ◽  
W. Lense Meyer
Keyword(s):  
Organic Acids ◽  
Aqueous Solutions ◽  
Reference Electrode ◽  
Formation Constants ◽  
Glass Electrode ◽  
Metal Phosphate ◽  
Electrode Pair ◽  
Phosphate Ions

The possible formation of organo–metal–phosphate complexes (O–M–P) in aqueous solutions is examined by potentiometric titration analysis. The complex-forming solutions contain Al3+-ions or Fe3+-ions, organic acids (salicylic, phthalic, oxalic, and citric acids) and phosphate ions. The titrations are done within the precipitation-free pH-region from 2 to 4.5 (approximately) at 25 °C under nitrogen at an ionic strength of 0.2 M KCl. The calibration of the electrode pair (glass-electrode, calomel-reference electrode) and the determination of the formation constants are facilitated by analyzing the pertinent curves with the ACBA-(Arena etal.) and MINIQUAD-(Gans etal.) computer programs. The results suggest (i) that O–M–P complexes are readily formed, and that the power of selected organic acids to form ternary mixed-ligand complexes with Al3+-ions and phosphate ions decreases in the order salycilate > citrate > oxalate > phthalate. Also, Fe3+-ions are found to be more strongly bound by salicylate and phosphate ions than Al3+-ions. The effect of O–M–P formation on the chemical speciation of Al in buffered aqueous solutions containing mineral nutrients for the growth of biological organisms is demonstrated for a special case study.

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

Sorption of Lead by the Selective Ion Exchanger Ostsorb DETA

1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Ion Exchanger ◽  
Preconcentration Procedure ◽  
Bead Cellulose

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.

scholarly journals The Determination of Gastric Acidity by the Glass Electrode

1965 ◽  
Vol 49 (2) ◽  
pp. 178-188 ◽  
Author(s):  
Edward W. Moore ◽  
Robert W. Scarlata
Keyword(s):  
Gastric Acidity ◽  
Glass Electrode
Sign in / Sign up

Export Citation Format

Share Document