Anion exchange extraction of tallium (III) and mercury (II) complex salts and application of the procedure to extraction-photometric determination of the microquantities of mercury (II)

2021 ◽  
Vol 87 (5) ◽  
pp. 20-26
Author(s):  
Yu. V. Matveichuk

The goal is to study the anion-exchange extraction of complex thallium (III) and mercury (II) halides (chlorides, bromides, iodides) by a method of a competing intermediate ion using the anions of various dyes — methyl orange, sodium picrate, 2,4-dinitrophenol, methyl red. Mercury (II) and thallium (III) are poisons of high toxicity. The developed method was used to study the anion-exchange extraction of acidocomplexes A solution of methyl orange trinonyloctadecylammonium (TNODA) in toluene was used as an extractant. The method provides determination of mercury (II) with an accuracy of ±2% when the concentration in the initial solution ranges within 2 – 8 × 10–8 mol/liter. It is shown that the values of the exchange constants for the same metal are larger for iodide complexes than for bromide and chloride ones. The extractability of metal halide complexes is mainly determined by their mass. Anions with a large mass have a large surface area, a low charge density, and are weakly hydrated, and thus are better extracted. The results of anion-exchange extraction were used to develop a procedure for the extraction-photometric determination of mercury (II) in granosan (ethylmercury chloride a prohibited insectofungicide of the 1st hazard class) the illegal use and storage of which could be a source of mercury pollution of groundwater in a number of regions of the Republic of Belarus. The relative error of determination does not exceed ±2%.

1965 ◽  
Vol 48 (6) ◽  
pp. 1095-1100
Author(s):  
James P Ussary ◽  
Charles W Gehrke

Abstract Three primary standard grade potassium salts, eight Magruder check samples, and 18 commercial fertilizer samples were analyzed by three methods. Primary standards gave an average recovery of 100.0% and an average range of 0.21% K20. Magruder check samples averaged 0.09% K20 higher by the modified flame photometric method than the grand averages of the STPB results on the respective Magruder reports. The modified flame photometric method averaged 0.02% K20 lower than the official flame photometric method and 0.11% K20 higher than the official STPB method on 18 commercial fertilizer samples. The automatic flame photometric method, without anion exchange cleanup, is rapid enough for routine analysis and is as accurate and precise as the AOAC official methods. The method was also applied to the direct available P205 extract. Results on three primary grade potassium salts, seven Magruder check samples, and 13 commercial fertilizer samples were as accurate and precise as the official STPB method.


1984 ◽  
Vol 49 (9) ◽  
pp. 2078-2095
Author(s):  
Milan Kotouček ◽  
Josef Růžička

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.


1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.


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

Sign in / Sign up

Export Citation Format

Share Document