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- Author or Editor: W. Maenhaut x
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Abstract
Atmospheric particulate samples were collected at the geographic South pole, using cellulose and polycarbonate filters and cascade impactors. The samples were analysed for 40 elements by instrumental neutron activation analysis. From the filter samples atmospheric concentrations for 33 elements could be obtained. The highest atmospheric concentrations were found for S: 49 ng/standard cubic meter (SCM) of air, Na: 3.3 ng/SCM and Cl: 2.6 ng/SCM. In the cascade impactor samples, only a few elements were observed above blank. For these elements it could be concluded that they are associated for over 80–90% with submicron size paricles.
Abstract
Instrumental neutron activation analysis /INAA/ was applied to measure trace elements in head hair of 19 patients with impaired renal function /14 males and 5 females/ and of 40 normal individuals /20 males and 20 females/. It was the aim to use head hair as a possible indicator of total body trace elements status and to investigate whether significant changes occur as a result of chronic hemodialysis. The elemental concentrations of 20 elements /i.e. Na, Mg, Al, Cl, K, Ca, V, Mn, Fe, Co, Cu, Zn, As, Se, Br, Ag, Cd, Sb, I and Au/ are presented and compared with published data. The present study revealed that the hair of the dialysis patients contained about ten times more iodine than that of the control group. No significant differences were observed for the other elements measured, except for sodium and antimony.
Determination of trace impurities in tin by neutron activation analysis
III. Simultaneous determination of 15 elements
Abstract
A method was developed for the determination of 15 trace elements in tin. High-purity tin samples (99.9999% and 99.999%) as well as tin of technical quality were analysed. Reactor neutron activation of the tin samples was followed by distillation of the matrix activities from a HBr−H2SO4 medium and Ge(Li) gamma-ray spectrometry of the distillation residue. The sensitivity of the method is generally high. For the high-purity samples the detection limits vary from 0.02 ppb (scandium) to 200 ppb (iron) for irradiation of 1 g of tin for 1 week at a thermal flux of 5·1012n·cm−2. ·sec−1. To decontaminate the surface of the tin samples, pre- and post-irradiation etching procedures were applied. The efficiency of these etching techniques was studied.
Abstract
For the determination of very low concentrations of copper in tin, an analytical method involving reactor neutron activation was developed whereby the copper activity was separated from the tin matrix by extraction of the Cu(I) cuproin complex in n-amyl alcohol. A new decontamination technique was sought in order to remove the copper contamination present on the tin surface. Pre-irradiation removal of the tin surface combined with post-irradiation etching appeared to be the most efficient.
Abstract
Determination of trace impurities in tin by neutron activation analysis
II. Determination of indium and manganese
Abstract
Two methods are described to determine indium and managenese in high-purity tin. In the first method indium and manganese are separated from the tin and antimony matrix activities on Dowex 1X8 anion exchanger. Tin and antimony are adsorbed in 10M HF while indium and manganese are eluted. In the second method the incident γ-ray intensity due to the tin matrix is reduced by placing a lead absorber between the sample and the detector. The reproducibility and the sensitivity of both methods are of the order of 10 ppb for manganese and of 1 ppb for indium for 1 g samples and a neutron flux of 1011 n·cm−2·sec−1.
Determination of trace impurities in tin by neutron activation analysis
I. Determination of arsenic, selenium and antimony
Abstract
Arsenic, selenium and antimony were determined in four different tin samples. After distillation from HBr−H2SO4 medium arsenic and selenium were precipitated with thioacetamide, and antimony was subsequently separated by deposition on iron powder. The separated samples were counted on a high-resolution Ge(Li) γ-spectrometer. The sensitivity of the method is highly satisfactory.
Abstract
Abstract
Equations to calculate the second order reaction interferences in activation analysis have been derived. A simple approximation as well as the exact solution have been investigated. A new algorithm is proposed for fast and accurate calculations, without the need of a computer with high precision arithmetic. The method can be used for all higher order reaction chains.
