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  • Author or Editor: C. Vandecasteele x
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Abstract  

Cadmium, thallium and lead are determined in environmental samples using the111,112,113Cd(p,xn)111In,203Tl(p,3n)201Pb and206,207,208Pb(p,xn)206Bi reactions.111In.201Pb and206Bi are chemically separated by anion exchange and anodic deposition of lead(IV). oxide. Detection limits are 6, 44 and 25 ng/g for cadmium, thallium and lead, respectively. The results obtained for certified reference materials are in good agreement with the certified values.

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Abstract  

The determination of boron in magnesium oxide using the10B/p, /7Be,10B/d, n/7Be, and10B/d, n/11C reactions is described. Lithium interferes the nuclear reactions leading to beryllium-7. Combination of a proton and deuteron irradiation, each followed by measurement of the induced beryllium-7 activity, allows a simultaneous determination of boron and lithium. The10B/d, n/11C reaction is free from nuclear interferences. The boron concentration ranges from 1.5 to 850 g g–1. The results obtained by the two methods are in good agreement.

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Abstract  

The determination of boron in rocks by charged particle activation using the10B(d, n)11C reaction is studied. A sample holder that allows reproducible irradiation of powdered samples is developed.11C is separated as11CO2. For boron concentrations between 2.35 and 25.2 μg·g−1, the standard deviations ranges from 7.1 to 22.8%. The results for USGS reference silicate rocks and Moroccan phosphate rock are compared to those obtained by other techniques.

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Abstract  

Cadmium sulfide particles were prepared by precipitation from acid solution. A radiotracer technique with109Cd was applied to measure the solubility of cadmium sulfide at various pH's. Filtration, centrifugation, ultracentrifugation, and dialysis were used to separate the particles from the solution. Only the last two techniques proved to be successful. The solubility of cadmium sulfide in water (pH=7) is found to be: 7.9·10–5 mol·l–1 in contrast with the literature value of 9.0·10–6 mol·l–1. At low pH (1–4), the solubility agrees fairly well with the solubility calculated on the basis of generally accepted values for the solubility product and for the various complex formation constants, while at high pH (4–14) the solubility is higher than expected.

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Abstract  

Carbon is determined in gold layers electroplated on brass, by deuteron activatin analysis using the12C/d, n/13N reaction. The results range from 2 to 1300 g.g–1 and the relative standard deviation from 0.9 to 13%. It is quantitatively shown that the hardness of the gold increases with the carbon concentration and that the carbon concentration decreases with increasing plating temperature and increases to a certain limit with the plating current density.

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