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Nondestructive determination of nitrogen in biological and other materials by photon activation analysis
Krausová, Ivana ; Mizera, Jiří ; Chvátil, David ; Krist, Pavel ; Řanda, Zdeněk ; Kučera, Jan ; Štursa, Jan
A procedure has been developed for assaying nitrogen in biological materials by means of instrumental photon activation analysis (IPAA). The determination has been based on counting of the non-specific 511 keV annihilation gamma rays of 13N, product of the photonuclear reaction 14N(γ, n)13N and a pure positron emitter. IPAA allowed determination of nitrogen down to 1 wt.%. in selected biological reference standards - NIST RM 8433 Corn Bran, 1547 Peach Leaves, 8414 Bovine Muscle, and 1577b Bovine Liver. The optimized procedure was applied also to assaying nitrogen in pulverized nanodiamond intended for medical purposes.
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Non-destructive determination of nitrogen in biological and other materials by the photon activation analysis
Krausová, Ivana ; Mizera, Jiří ; Chvátil, David ; Krist, Pavel ; Řanda, Zdeněk ; Kučera, Jan ; Štursa, Jan
The study presents a procedure for assaying nitrogen in biologocial materials by means of instrumental photon activation analysis (IPAA). The determination has been based on counting of the non-specific 511 keV annihilation gamma rays of 13N, product of the photonuclear reaction 14N(γ, n)13N, which is a pure positron emitter. IPAA allowed determination of nitrogen down to 1 wt.%. in selected biological reference materials - NIST RM 8433 Corn Bran, 1547 Peach Leaves, 8414 Bovine Muscle, and 1577b Bovine Liver. The optimized procedure was applied also to assaying nitrogen in pulverized nanodiamond intended for medical purposes.
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Determination of 129I in environmental samples by neutron activation analysis
Krausová, Ivana ; Kučera, Jan ; Světlík, Ivo
A new RNAA method with pre-activation separation has been developed for determination of 129I and the ratio 129I/127I in environmental samples. Iodine is separated from samples prior to irradiation by combustion in oxygen stream and trapping in LIOH/(NH4)SO3 solution. Post-irradiation radiochemical separation of iodine consists in CHCl3 extraction of elemental iodine and PdI2 precipitation. The procedure has been verified by analysis of a reference seaweed sample Fucus serratus, and its basic metrological parameters were determined. The methods has been applied to analysis of aerosol filter, moss, lichen, sediment and bovine thyroide samples collected in the vicinity of the Temelín nuclear power plant.
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Recoveries of elements following fast decomposition of biological and other materials by alkaline-oxidative fusion
Kučera, Jan ; Krausová, Ivana
Recoveries of selected elements were studied for fast decomposition of biological and other materials using alkaline-oxidative fusion in a mixture of NaOH and Na2O2 at 850 to 900°C. The procedure yields total mineralization of samples within 2 to 3 minutes. It is therefore especially suitable in radiochemical activation analysis (RAA) for determination of elements forming short-lived radionuclides. Recoveries of the elements F, Si, S, Cl, Ti, V, Mn, Ge, As, Br, Mo, Ru, In, Sb, I, Re, Os, and U determined using radiotracers were in the range 95-100 %, while those for Se and Hg were significantly lower and highly variable.
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