Application of Fast Grey RA to the spectrophotometric determination of copper in soft tissues of Egyptian camels

Copper in different organs of Egyptian camels was successfully determined spectrophotometrically using Fast Grey RA. Its values amounted to: 200.8 ± 11.4, 155.8 ± 16.1, 142 ± 6.8, 128.3 ± 6.9, 117.6 ± 5.1, 113.0 ± 5.3, 86.3 ± 3.2, 79.0 ± 5.2, 76.3 ± 3.7, 66.3 ± 4.3, 59.8 ± 1.7, 57.6 ± 3.0, 53.0 ± 2.2, 36.3 ± 2.3 and 3.03 ± 0.32 μg/g dry matter of hair, liver, spleen, lung, heart, integument, muscle, brain, lymph gland, small intestine, large intestine, kidney, adrenal, fourth stomach, and hump, respectively, while 1 ml citrated blood contained 6.97 ± 0.64 μg. Of 16 elements mentioned, only vanadium interferes with the determination of copper in hair by the present method.     

On the reaction between iodide and mercury(II)

A survey on the iodide-mercury(II) reaction and its analytical uses is given. Titrations of iodide with mercury(II) in various acidities, using nitrate, acetate, and chloride as titrants and silver or platinum amalgam as the indicator electrode, showed that mercury(II) nitrate is the best titrant giving 0.46 V/0.1 ml potential break in comparison with 0.14 V/0.1 ml of mercury(II) chloride and 0.35V/0.1 ml of mercury(II) acetate, all titrants being 0.05 M in mercury(II).     

Radiation effects on polymers—IV: Straight radiation vulcanization of styrene-butadiene rubber mixes

Vulcanization of styrene-butadiene rubbers was carried out by gamma radiation in air. For unloaded unextracted rubbers, the dose required for optimum cross-linking was about 40 megaroentgens (MR). Elimination of foreign materials and stabilizers and also incorporation of filler affected the vulcanization. Loaded samples gave vulcanizates with best complex physico-mechanical properties for filler content of 50 (phr) and a dose of 30 MR. Evaluation of various fillers has shown that the best properties were obtained with HAF among the black fillers and silica in the case of white fillers.     

Extraction of Eu(III) by dinonylnaphthalenesulfonic acid and synergistic effects of crown ethers and trioctylphosphine oxide

The extraction of Eu(III) by dinonylnaphthalenesulfonic acid (HDNNS) in benzene from nitrate and perchlorate solutions has been investigated. For nitrate solutions the ionic strength of the aqueous phase was kept constant at 0.1M using NaNO₃–HNO₃ mixtures. The Eu distribution was measured at different temperatures. The following stoichiometric formulae for the Eu species in benzene were derived: Eu(NO₃) (H_n–1 (DNNS)_n)₂ and Eu(H_n–1 (DNNS)_n)₃, from the nitrate and perchlorate medium respectively (n being a small number, e.g. 1, 2 or 3). The equilibrium constants were calculated and the thermodynamic parameters of the system were determined. When adding dibenzo-24-crown-8, dicyclohexyl-18-crown-6 or trioctylphosphine oxide, no synergism, but rather antagonism was observed.     

Pallatriazo — A sensitive and selective reagent for the spectrometric determination of palladium(II)

Summary Based on an investigation of the functional and active analytical groups, a new trisazo derivative, pallatriazo, is proposed as a reagent for determining Pd(II) spectrometrically. This reagent shows high sensitivity, allowing palladium determination in the concentration range 0.05–4g Pd(II)/ml even if platinum is present up to the ratio Pd(II)Pt(IV)=130.

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Pallatriazo — ein empfindliches und selektives Reagens für die spektrometrische Bestimmung von Palladium(II) (Vorläufige Mitteilung)

Zusammenfassung Auf der Grundlage einer Untersuchung der funktionellen und analytischaktiven Gruppen wurde ein neues Trisazo-Derivat, Pallatriazo, als Reagens für die spektrometrische Bestimmung von Pd(II) vorgeschlagen. Es zeigt hohe Empfindlichkeit und gestattet die Pd-Bestimmung im Gebiet 0,05–4g Pd(II)/ml, auch wenn Platin in 30fachem Überschuß anwesend ist.

     

Effect of some environmental ligands on the sorption of radionuclidesby peat humin

Summary In a previous paper we studied the interaction of the radionuclides ^110mAg, ⁶⁰Co and ⁶⁵Zn with peat humin. These nuclides are among the fission or corrosion products in nuclear reactors. The aim of this paper is to study the effect of certain ligands, which are present in the environment, such as humic acid, fulvic acid, EDTA and urea, on the sorption of these radionuclides by humin. The obtained results indicated that urea has no effect on the sorption of Co and Zn by humin, and only a little in case of Ag. However, the presence of the other ligands (humic acid, fulvic acid or EDTA) leads to different decreases in the sorption of the three nuclides by humin. The results are interpreted in the light of the complex formation between ligands and the metal cations and of the strength of binding of these cations to the humin sorbent. The release of Ag⁺in the presence of different ligands was found to follow the order: humic acid>EDTA>fulvic acid>urea. In the case of both Co²⁺and Zn²⁺, the sequence is changed to be: EDTA>humic acid>fulvic acid>urea, with a higher release in the case of Zn²⁺. The results showed that cobalt is bound more strongly to humin than silver and zinc. The sulphur content of the humic fractions plays a significant role in the competition for silver and zinc.     

Solochrome Green V as a new analytical reagent

Summary The acid-base properties of Solochrome Green V have been studied with the object of testing its use as a metal indicator or colorimetric reagent. The pK values of the three steps of ionisation of the free acid were evaluated. The dye has proved to be a suitable indicator in EDTA titrations of zinc and manganese as well as a colorimetric reagent for the microdetermination of zinc. The method is highly sensitive that by its application 0.05 ppm Zn can be determined with fair accuracy.     

Radiation effects on polymers—V: Vulcanization of styrene-butadiene rubber (SBR) with gamma radiation and coagents

Possible enhancement of the radiation-induced vulcanization of SBR by polyfunctional allyl and vinyl monomers, was tested. Polyfunctional allyl esters did not enhance the radiation vulcanization; in fact they retarded the process and so can be considered as “antirads”. Di- and tri-vinyl monomers acted individually as effective radiation coagents. In their presence, the dose required for satisfactory curing was 7–10 MR instead of 40 MR in the case of unenhanced vulcanization. The results indicate that vinyl esters are more effective coagents than vinyl amides. The physico-mechanical properties of vulcanizates, obtained in the presence of 10–30 parts of vinyl coagents per 100 parts of SBR. are of the same level as those obtained by conventional sulphur vulcanization.     

Synthesis and structural characterization of [Ni(Me2NCH2CH2CH2N=CHC6H4O)2]

The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schiff base ligand Me₂NCH₂CH₂CH₂N=CHC₆H₄OH(LH) are described. The complex crystallizes in the monoclinic space group P2₁/c, with a = 10.180(2), b = 15.169(3), c = 15.293(4) Å, = 106.69(2)°, and Z = 4. The Ni atom shows a distorted fac-octahedral geometry, with the two Ni—N(Me₂) bonds being significantly longer than the two Ni—N(imino) bonds, 2.284(9), 2.310(9) vs. 2.051(2), 2.055(2) Å.