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Summary  

Instrumental and radiochemical neutron activation analysis (INAA and RNAA, respectively) were used to analyze several consumed food items in Libya for the detection of low level concentrations of mercury and selenium. Selenium was determined using both short- and long-term irradiation, while mercury was determined in the long-term irradiation mode. At RNAA, after wet-ashing of samples in a microwave digestion unit, mercury was extracted with Ni(DDC)3/CHCl3, and selenium was precipitated in elemental form with ascorbic acid. For quality control, NIST reference materials were analyzed using the same procedures as for the food samples. The results of the analytical modes used were compared.

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Abstract  

Since there is no database in Libya defining the intake of the individuals from different essential (minor and trace) and toxic elements provided through food, drinking water and aerosol, a project has been proposed with the cooperation of IAEA to determine the concentration of a number of elements such as Cs, Fe, Cr, Rb, Sc, Se, Co, Zn in the three mentioned sources. Emphasis was placed on the use of nuclear and nuclear-related techniques. In this paper, the primary results are presented for the concentration of minor and trace elements in some vegetables, spices and other foods which are widely used in the Libyan meals. Instrumental neutron activation analysis utilizing a 10 MW water pool reactor and a γ-ray spectroscopy facility was employed. For quality control, certified reference materials were analyzed simultaneosly with the samples which show good agreements compared with the certified data. Emphasis was given to both elements iron and zinc for their importance.

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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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