Authors:N. Singh, S. Mohan, and G. Balasubramanian
A very sensitive extraction spectrophotometric method for the analysis of uranium based on the extraction of a uranium—benzoate—crystal
violet complex by a mixture of xylene and benzene is described. The absorbance maximum is at 606 nm and molar absorptivity
is 4.28·104 l·mol−1·cm−1. The interference due to a number of anions and cations studied without any pre-extraction was found to be within permissible
limits. The method has been used for determining uranium in a synthetic solution, i.e., uranium in the presence of various
other ions. The interference due to some cations was eliminated by the use of a masking agent (boric acid).
A method has been developed for the extraction of Au(III) with 2-mercaptobenzimidazole into n-butanol.199Au has been used as a tracer for establishing the ideal extraction parameters such as effect of pH, time of equilibration,
solvents and anions. Separation factor and decontamination factor have also been evaluated to determine the selectivity of
the method with respect to various elements. The interfering elements were suppressed by the use of suitable masking agents
which increased the selectivity. The stoichiometry of metal to reagent was determined by the method of substoichiometric extraction
and slope ratio method.
Authors:M. Koyama, T. Mitsuji, O. Tochiyama, and T. Fujinaga
A rapid separation of radioactive cesium by the solvent extraction method was investigated. Cesium ions are quantitatively
extracted with [Cr(NH2C6H5)2(NCS)4]− into nitrobenzene. EDTA is an effective masking agent for other polyvalent cations. The extracted cesium can be back-extracted
into the aqueous phase by shaking with 6N HCl. The method was applied to samples of a natural mixture of fission products and a reactor coolant. The decontamination
factors for other predominant isotopes in fission products were 102∼104. The separation of137mBa from a mixture of137Cs and137mBa is also described.
A fairly simple radiometric method has been developed for the quantitation of microgram amounts of mercury in lead samples
of different purity grades. It is mainly based on 3 steps; (i) the removal of most interfering cations with ferric hydroxide
scavenger in the presence of a suitable masking agent, (ii) the separation of mercury as hydrated mercuric oxide from a highly
alkaline medium, (iii) its distillation as mercuric chloride followed by precipitation as the sulfide. The method is reproducible
and the results which show, in general, a standard deviation of ±4.29% are compared with those obtained by atomic absorption
(4.48%) and spectrophotometric (13.13%) techniques.
Authors:H.A. Morais, L.M. De Marco, M.C. Oliveira, and M.P.C. Silvestre
Hydrolytic parameters were tested to prepare casein hydrolysates with high oligopeptide content for dietetic purpose, using papain. Employing a temperature of 37 °C and an E:S ratio of 2% was the most economical condition for large-scale manufacture. The encapsulation in liposomes was used for masking the bitterness, and was also able to reduce the hydrophobicity as well as to keep the chemical stability during 60 days of storage. The UV spectrometry with second derivative transformation was used to measure the encapsulation rate, which changed from 56% to 62%. The size distribution of vesicles was in the range of 500 to 1000 nm.
A radiochemical solvent extraction method has been developed for the simultaneous determination of submicrogram amounts of Cd and Hg using115mCd and203Hg tracers respectively and thionalide as a single complexing reagent. Hg was determined by 0.05% thionalide in ethyl methyl ketone (EMK) at pH 8.5, masking Cd with 0.1M KCN. From the aqueous phase Cd was demasked using formal-dehyde-acetic acid, pH adjusted to 9.5 and extracted into 0.05% thionalide in chloroform. The method is simple, fast and yields accurate results.
Tropolone reacts with uranium/VI/ and forms orange yellow precipitate extractable in chloroform. The maximum absorption occurs at 405 nm and the absorbance is found to remain constant in the pH range of 5.5 to 7.0. Beer's law is obeyed upto 37.6 ppm of U/VI/. The sensitivity of the colour reaction is 0.034 g cm–2. Most of the common ions do not interfere. The method becomes more selective by masking some of the interfering cations with EDTA. The method was applied to determine uranium in monazite sand.
Transport of trivalent rare earth elements-REE (Sc, Y, Ce, Eu, Gd, Tm, Yb) from nitrate medium through SLM containing TOPO in n-dodecane, supported on a nucleoporous filter, into a strip solution with EDTA, has been studied. Permeability coefficients of metal transport decreased with increasing of their atomic number except for Ce and Tm. At higher concentration of TOPO in the membrane, metal transport was faster, but the differences among the transport rates of the investigated elements decreased. A good separation of Ce from its binary mixtures with other investigated REE was achieved using DTPA as masking agent, added the feed solution.
The west to east oriented graves of an Early Avar period cemetery came to light at Szihalom-Budaszög in 1996. Two clay mugs turned on a fast wheel bespeak local Gepidic ceramic traditions. A wooden amulet capsule can likewise be linked to Pannonian and Transylvanian communities with a Merovingian culture. The gold and gilt bronze mounts of the capsule suggest the burial of an individual from the community’s elite. The gold mounts of the capsule are decorated with four masks arranged in a cross-like design. The stylistic and iconographic parallels to the masks point towards Italy and the regions north of the Alps. The capsule provides evidence for syncretic beliefs: the amulet was probably believed to have both pagan magical and Christian protective properties. The small cemetery was used by a local Gepidic community with good contacts with Western Europe living under the overlordship of the Avar Khaganate.
The creative reception of Anton Chekhov in contemporary Hungarian literature often takes the form of a role-play in which poets put on an authorial mask that displays Russian literary references, while their Chekhovian intertexts constitute an organic part of a playful evocation of classic Russian literature. The form of the mask lyric, including especially that of the so-called “oroszvers” (verbatim: a Russian poem), is also characteristic of poetry from across the border in Transylvania; more specifically, of the writers’ generations starting out in the sixties and seventies, named after the book series entitled Forrás (Springs), growing up on the heritage of the 20th-century Hungarian poet Attila József, and apparently representing this heritage but, at the same time, introducing a new form of expression as well. This study focuses on the poetics of two such contemporary authors, László Király (b. 1943) and András Ferenc Kovács (b. 1959), in whose poetry I wish to examine the phenomenon belonging to the category of literary mystification, while analyzing the manifestations of the typical Chekhovian protagonist and the Chekhovian “atmosphere” as transposed into poetry.