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Abstract  

The separation of fluoride by extraction with toluene solution of triphenyltin chloride has been studied. Quantitative isolation of fluoride from solutions with a wide acidity range (pH 4.0–11.5) has been established. It is suggested that interferences by Ca, Mg, Fe, and Al can be avoided by masking these elements using sulfate and hydroxyde ions. Interference by phosphate ions can be overcome in a similar fashion. The halogenated species can be masked by mercury nitrate. Detection limit for fluorine determination is about 3 g for a neutron generator flux of 2·1111 n·cm–1·s–1. A method for fluorine assay in water using a neutron generator with a detection limit of 1 ppm has been developed.

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Abstract  

γ-Zirconium phosphate-phosphite, γ-Zr·PO4·H2PO3·2H2O, (γ-ZrPP), was prepared and characterized. Direct treatment of γ-zirconium phosphate-phosphite with an ethanol solution of 0.1M 1,10-phenanthrolin and 2,2'-bipyridyl gave the well defined composites, γ-Zr·PO4·H2PO3(phen)0.15·H2O and γ-Zr·PO4·H2PO3(bipy)0.18·0.6H2O respectively.K d values of a mixture of lanthanide ions: La3+, Sm3+, Eu3+ and Yb3+ for the intercalated products and for γ-ZrPP in HNO3 solution at room temperature and at pH 2 and 4 were determined by a radiotracer technique.140La,152mEu,153Sm and175Yb radioisotopes were used for the equilibration experiment using 500 μl (4.0·10−5 mmole) each of the solutions of the tracers as a mixture in 7.5 M HNO3 solution at the desired pH with 0.1 g of γ-ZrPP and of the intercalated products. The selectivity order was found to be dependent on the nature of the ligand and on the pH. The 2,2'-bipyridyl product posseses, at pH 2 in general, a highK d value, specially for Sm3+ (9815.9) compared to that of the 1,10-phenanthrolin product (3375.5) and to γ-ZrPP (419.8). This could be attributed to partial deintercalation of the 2,2'-bipyridyl at pH 2 and increasing of ionogenic groups.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Shakshooki
,
E. Arafa
,
F. Siala
,
M. El-Mellah
,
S. El-Hamruni
,
A. Bejey
, and
F. Beshewa

Abstract  

Glassy tin arsenate, Sn(HAsO4)2·2.7H2O (SnAs) was prepared and characterized. The uptake of lanthanide ions La3+, Sm3+, Eu3+, and Yb3+ was followed on the glassy tin arsenate in HNO3 solution at pH 1,2 and 4. The radiotracers are140La,153Sm,152mEu, and175Yb. 500 μl (4.0·10−5 mmole) of each solution of the tracer as a mixture plus 7.5 ml HNO3 solution at the desired pH were equilibrated with 0.1g of SnAs. The selectivity order (K d values) was found to be dependent on the pH. At pH 2 theK d values were high for all the studied metal ions [Yb (2065.4)>La (1976.1)>Sm (1826.4)>Eu (1754.4)]. TheK d values at pH 1 and 4 are quite low for all the metal ions studied. At pH 1 they range from ≈144 to 156 and at pH 4 they range from ≈70 to 79.

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Abstract  

We have determined the concentration of 25 trace elements in crude petroleum from seven Libyan oil fields by instrumental neutron activation analysis. Crude oil samples were irradiated with a thermal neutron dose rate of 1012 and 1013 n·cm–2·s–1 in the Tajoura research reactor. The concentration of U, Br, Mg, Cu, Na, V, Cl, Al, Mn and Ca is in a range of 0.015 to 84 ppm and that of sulphur of 0.12 to 1.8%. The elements Sc, Cr, Ni, Fe, Co, Zn, Ag, Se, Sb, Ba, Cs, Yb, Hf and Hg have a concentration range of 0.009 to 8747 ppb. The coefficients of variation are within 10%. The elements V and Ni occur as both porphyrin and non-porphyrin and the ratio of these two forms varies over a wide range. The V/Ni ratios are located between 0.17 and 6.67, which are comparable to the reported values for the crude oils from other countries.

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Abstract

Purpose: To investigate the concentration of myocilin in the aqueous humor of open-angle glaucoma (OAG) patients, including correlations with glaucoma subtypes and intraocular pressure (IOP). Patients and Methods: The study comprised 85 patients with OAG. Glaucoma subtypes included 35 cases of high tension glaucoma (HTG), 25 cases of normal tension glaucoma (NTG), and 25 cases of exfoliation glaucoma (ExG). Forty-five patients with senile cataract were included as control. The concentrations of myocilin in the aqueous humor were measured by plotting the densitometry readings of the aqueous humor samples against a recombinant myocilin standard curve. Additionally, the relationships with the glaucoma subtypes, IOP, and glaucoma severity were analyzed. Results: A significantly higher percentage of patients in the glaucoma subgroups were positive for myocilin compared with the cataract group. The mean myocilin concentrations among the glaucoma positive case subgroups were not different (P=0.326). Myocilin levels were significantly higher in human HTG compared with cataract group (P<0.05). There were no significant correlations between the myocilin concentration and the IOP or the severity of glaucoma. Conclusion: Myocilin-positive patients were significant in the glaucoma subgroups than in the cataract group, with a highly significant difference observed for HTG patients.

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