scholarly journals Extraction-photometric determination of osmium using quaternary water-thiopyrine-trichloroacetic and orthophosphoric acid system

2020 ◽  
Vol 99 (3) ◽  
pp. 61-65
Author(s):  
L.S. Egorova ◽  
◽  
E.A. Leites ◽  
Keyword(s):  
Ascorbic Acid ◽  
Organic Solvent ◽  
Orthophosphoric Acid ◽  
Photometric Determination ◽  
Model Mixture ◽  
Acid System ◽  
Optimal Conditions ◽  
Liquid Component ◽  
Effect Of Copper

The article is devoted to the extraction-photometric determination of osmium. The aim was to modify the well known extraction-photometric determination of osmium by replacing chloroform, used as an organic solvent in a traditional extraction system, on to water, which is the only liquid component in the layering system. This made it possible to eliminate the toxic organic solvent from the system. The optimal conditions for the osmium extraction were selected, taking with the fact that the consumption of thiopyrine, as an expensive reagent, should be minimal. The results of the developed methodology for determining microgram amounts of osmium with thiopyrine were presented by the example of a model mixture corresponding to the composition of a platinum sponge. The interfering effect of Al (lII), B (lII), Bi (IIl), Fe (llI), Au (lII), lr (II), Cd (ll), Co (II), Ca (II), Si ( IV), Mg (II), Mn (II), Cu (Il), Mo (VI), As (V), Ni (lI), Sn (lV), Pd (Il), Rh (II), Pb (II), Ag (I), Sb (IIl), Te (IV), Cr (IlI), Zn (Il) contained in a platinum sponge was investigated. The interfering effect of copper has been established, which is eliminated by masking with ascorbic acid.

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.

scholarly journals The development of methods for the determination of residues of the insecticide pymetrozine in water, soil, cucumber and rape

2019 ◽  
pp. 79-87
Author(s):  
Mikhail F. Zayats ◽  
Sergey M. Leschev
Keyword(s):  
Experimental Data ◽  
Orthophosphoric Acid ◽  
Residue Level ◽  
Inorganic Salts ◽  
Diode Array ◽  
The European Union ◽  
Optimal Conditions ◽  
Ultraviolet Detection ◽  
Maximum Residue Level

Based on the literature data on the solubility of pymetrozine in water and organic solvents, as well as experimental data on the extraction of pymetrozine from water, soil and plant matrices, the optimal conditions for the extraction of pymetrozine from water; soil; cucumber; rape seeds, oil and green pods were selected. The conditions for cleaning extracts were selected as well. At the first stage, acetonitrile, a mixture of dichloromethane – isopropanol, or a mixture of dichloromethane – methanol in the presence or absence of inorganic salts were used for extraction of the pesticide. Pymetrozine was found to be a highly hydrophilic substance. For the purification of extracts of pymetrozine from plant matrices the extraction systems hexane – 0.02 mol/L aqueous solution of orthophosphoric acid, hexane or chloroform – aqueous solutions of ammonium sulfate were successfully used. The samples, obtained after this treatment, were pure enough to determine the residual amounts of pymetrozine in them at the maximum residue level (MRL), determined in Russia and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.

Sorption-photometric determination of ascorbic acid using molybdosilicic heteropolyacid and polyurethane foam after microwave irradiation

1998 ◽  
Vol 373 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
S.G. Dmitrienko ◽  
L.V. Goncharova ◽  
A.V. Zhigulev ◽  
R.E. Nosov ◽  
N.M. Kuz̀min ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Microwave Irradiation ◽  
Polyurethane Foam ◽  
Photometric Determination
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