Determination of trace elements in biological materials by instrumental epithermal neutron activation analysis

The use of reactor epithermal neutrons in instrumental activation analysis is described for the determination of trace elements via long-lived isotopes. A boron carbide filter is used. Results of analyses of human erythrocytes, plasma, urine and some biological reference materials are given to demonstrate the applicability of the method to biological samples. Bromine, iron, cesium, rubidium, selenium and zinc and cobalt are determined. The method provides accuracy and reliability similar to conventional thermal neutron activation but is faster. Limits of detection attainable with the two techniques are compared.     

Determination of trace elements in biological material by neutron activation analysis

Eighteen trace elements in biological material [grass /Imperata cylindrica/, mimosa plant /Mimosa pudica/, rice] by neutron activation method were determined. In the comparative analysis, we found the content of the same elements was different in the each material, although they were collected at the same place and the same sampling method was applied.     

Determination of trace elements in Brazilian rice grains and in biological reference materials by neutron activation analysis

Instrumental neutron activation analysis was applied to the determination of the elements Na, K, Br, As, Rb, Zn, Co, Fe and Sc in Brazilian rice samples and in biological standards. Hg and Se concentrations were determined by using a simple radiochemical separation. The chemical procedure was carried out by means of distillation of Hg and Se in HBr medium and subsequent precipitation of selenium by sodium metabisulfite and mercury by thioacetamide. The accuracy of the instrumental and radiochemical methods was evaluated by means of analysis of the Reference Materials NBS-Bovine Liver, Bowen's Kale and NBS-Rice Flour.     

Determination of trace elements in biological standard kale by neutron activation analysis

Fifteen elements at trace levels have been determined by neutron activation analysis in the biological standard kale distributed byBowen. La, Br, As, Se, Sc, Ag, Zn, Co, Cr, Sb, Eu, Fe, and Zr have been determined by a nondestructive technique using a high-resolution Ge(Li) detector. Two more elements, Au and Hg, have been determined after radiochemical separation. The nondestructive procedure is shown to yield data in generally good agreement with those obtained by destructive techniques. Potential sources of error in the nondestructive technique are discussed.     

Determination of trace elements in acid rain by reversed-phase extraction chromatography and neutron activation

A preconcentration neutron activation analysis (PNAA) method involving reversed-phase extraction chromatography on 8-hydroxyquinoline-loaded Amberlite XAD-2 resin has been developed for the simultaneous determination of selected trace elements in acid rain and natural water samples. Quantitative retention has been achieved for Co, Cu, Hg, V and Zn at pH 6.0 and for Cd at pH 7.0. Various factors that can influence the preconcentration procedure have been studied in detail. Concentrations of the elements have been determined by the direct irradiation of the resin without eluting them from the column. Both precision and accuracy of the PNAA method are very good. The detection limits vary between 0.01 and 3 ppb.     

Determination of 25 elements in biological standard reference materials by neutron activation analysis

Trace element analysis has been carried out on standard biological reference samples such as bovine liver, orchard and tomato leaves. Computer aided instrumental neutron activation analysis and, in some cases, preliminary chemical group separation followed by NAA were used. For Ca, Mg, Ni and Si special chemical separation and Cerenkov counting were applied. *** DIRECT SUPPORT *** A1353068 00003     

Determination of ten trace elements in meteorites and lunar materials by radiochemical neutron activation analysis

A procedure is reported for the determination of Ni, Ge, Ru, Au, Ir, Zn, Ga, Cd, In and U in meteorites and lunar materials. The precision in multiple determinations at the 95% confidence level is less than 10% except for gold (15%). Ruthenium and uranium are determined by counting ⁹⁷Ru and ¹⁰³Ru x-rays; the chemical yield is determined from ¹⁰⁶Ru added before sample dissolution. The activity of ^116mIn is determined with improved sensitivity from integral counts in the region 1.5–3.0 MeV on a NaI(TI) detector.     

Determination of arsenic and antimony in biological materials by solvent extraction and neutron activation

Arsenic and antimony in digested biological samples can be extracted with pyrrolidinecarbodithioate at pH 1 into chloroform and stripped with nitric acid for neutron-activation analysis (NAA). The extraction method eliminates interferences from matrix species, including Br and Na, making the accurate determination of low levels of As and Sb in biological materials feasible. The detection limits under the experimental conditions used are 0.005 and 0.006 mug/g for arsenic and antimony, respectively. A comparison of the results obtained for As and Sb in NBS biological standards by this method and by non-destructive instrumental neutron-activation analysis (INAA) is also given.     

Determination of trace elements in water by non-destructive neutron activation

A systematic study was undertaken in order to find out which of the most relevant elements can be determined in water under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples as well as natural water of different kind were used, brought to dryness by freeze-drying and irradiated in quartz at a neutron flux of 10¹⁴ cm⁻² s⁻¹ for 1 day. The trace element content in quartz ampoules of different origin was determined separately. The following elements are discussed in detail including possible interferences: As, Au, Br, Ca, Cd, Co, Cr, Cu, Eu, Fe, Hg, K, La, Mo, Na, Ni, Sb, Sc, Se, U, Zn. Presented at the Euroanalysis II Conference, Budapest, 25–30. Aug. 1975.     

Determination of trace elements in petroleum by neutron activation analysis

Instrumental neutron activation analysis (INAA) and Ge(Li) spectrometry have been used to determine Sc, Cr, Fe, Co, Ni, Zn, As, Se, Sb, Eu, Au, Hg, and U in crude petroleum. The technique involves no chemical separations and no pre-concentration of the samples by ashing is necessary, thus avoiding contamination or loss of volatile elements. The estimated detection limits in ppb for the elements are Sc (0.1), Cr (0.16), Fe (400.0), Co (0.6), Ni (1.1), Zn (200.0), As (6.0), Se (23.0), Sb (1.0), Eu (0.58), Au (0.11), Hg (4.3), U (1.5). Precision values ranged from 0.1% to 15% (relative standard deviation). Interferences in the Co and Fe determinations due to fast neutron reactions (n, p) and (n, α) on Ni isotopes are small and are easily corrected. Losses of As, Se, and Hg due to escape of volatile gases during irradiation are negligible     

Determination of trace elements in food by neutron activation analysis

Neutron activation analysis (NAA) methods have been developed for the determination of major, minor and trace elements in duplicate diets and individual food items. These include a cyclic instrumental NAA (CINAA) method for measuring Se content through its short-lived nuclide^77mSe; epithermal INAA (EINAA) for I and As; conventional INAA for Br, Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Sn and Zn; combination of EINAA and INAA for Al; radiochemical NAA (RNAA) for As, Au, Co, Cu, Fe, Hg, Mo, Sb, Se and Zn; and preconcentration NAA (PNAA) for U and Th. Accuracy of measurements have been evaluated by analyzing a number of biological and diet reference materials. Multielement concentrations of diets and foods have been measured by these methods.     

Determination of trace elements in petroleum by neutron activation analysis

Using thermal neutron activation and a large-volume high-resolution Ge(Li) γ-ray spectrometer, the feasibility of the determination of the concentrations of Na, S, Cl, K, Ca, V, Mn, Cu, Ga, and Br in crude oils has been demonstrated. This instrumental method, which requires neither a chemical separation technique nor pre-concentration or post-concentration of trace elements by ashing, eliminates many inherent errors associated with chemical determination. The method is sensitive, precise and suitable for routine analysis. Fast neutron (n, p) and (n, α) reactions do not appreciably interfere and where necessary corrections may be applied. Loss of volatile elements, e.g. chlorine and bromine, due to recoil during irradiation is negligible.     

Determination of molybdenum in biological materials by neutron activation

A method of the determination of molybdenum in biological materials by neutron activation is described. The method is based on the γ-spectrometric measurement of^99mTc after radiochemical separation of the latter by substoichiometric extraction with tetraphenylarsonium chloride using rhenium as inactive carrier. The method has been tested with reference materials.     

An accurate procedure for multielement neutron activation analysis of trace elements in biological materials

A procedure for radiochemical neutron activation analysis of biological materials for As, Cd, Co, Cu, Ga, Hf, Mg, Mn, Na, Sb, Sc, Se, Zn, and the rare-earth elements (REE) has been developed. Maximum control over accuracy has been emphasized. Samples are digested under reflux in the presence of carrier for every element determined, and a chemical yield is measured for every element assayed. The procedure has been tested by replicate analysis of National Bureau of Standards bovine liver sample (SRM-1577). Values agree to within their uncertainties with those given by NBS for the 9 elements of this group that they have analyzed. Accuracies at the 90% confidence level for elements in the liver sample are estimated as better than ±10% for Cu, Na, and Zn, between ±10 and ±25% for As, Co, Hg, La, Mn, and Se, and between ±25 and ±50% for Cd, Sb, Sc, and Sm.     

Determination of trace elements in cardiotonic drugs by neutron activation analysis

Potassium may be intimately involved to the action of cardiac glycosides. Chlorine and potassium also act as diuretics. The elements chlorine, manganese, potassium and sodium are determined by instrumental neutron activation analysis in all the cardiotonic drugs which are currently used in Greece. All the available pharmaceutical forms of these drugs were analysed (pills, injections, water solutions). It has been found that there is a wide variation among the different values for managanese, sodium and chlorine while for potassium values are relatively constant. Results are discussed from the pharmacological point of view. It is proposed to study the role of manganese in cardiotonic drugs as well as the effect of potassium addition in oral pharmaceutical form of cardiotonic drugs in decreasing the toxicity of cardiac glycosides.     

Determination of trace elements in fish by instrumental neutron activation analysis

Instrumental neutron activation analysis, INAA, was utilized for the determination of Al, Au, Br, Ca, Cl, Co, Cr, Cu, Fe, I, K, Mg, Mn, Na, Rb, Sc, V and W in 12 Tilapia Nilotica samples collected from the Aswan High Dam Lake following the destructive techniques.     

Determination of trace elements in tea leaves by neutron activation analysis

Instrumental neutron activation analysis has been employed to determine 14 trace elements in two brands of Iranian and foreign tea. The elements are: Br, La, Ba, K, Mn, Cl, Cr, Cs, Rb, Fe, Co, Zn, Sc and Au. The transference ratio of the elements into solution, when tea is leached by percolation, is also reported. It was found that some elements are totally transferred into solution and some are partially retained by the leaves.