Browsing by Author "Trautman, RL"

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    Can synchrotron micro-x-ray fluorescence spectroscopy be used to map the distribution of cadmium in soil particles?
    (CSIRO Publishing, 2007-10-30) Milham, PJ; Payne, TE; Lai, B; Trautman, RL; Cai, ZH; Holford, P; Haigh, AM; Conroy, JP
    Plants take up cadmium (Cd) from the soil, and the concentration of Cd in some plant products is a health concern. Plant uptake of Cd is poorly predicted by its concentration in soils; consequently, there is interest in the binding and distribution of Cd in soil. Synchrotron micro-X-ray fluorescence spectroscopy (micro-XRFS) is the most sensitive method of observing this distribution. We used beam-line 2-ID-D of the Advanced Photon Source (APS), Argonne, to test whether this technique could map the Cd distribution in 5 soils from Greater Sydney that contained 0.3-6.4 mg Cd/kg. A subsample of one soil was spiked to contain similar to 100 mg Cd/kg. Cadmium was readily mapped in the Cd-enriched subsample, whereas in the unamended soils, only one Cd-rich particle was found; that is, sensitivity generally limited Cd mapping. We also examined a sample of Nauru phosphorite, which was a primary source of much of the Cd in farm soils on the peri-urban fringe of Greater Sydney. The phosphorite contained similar to 100 mg Cd/kg and the Cd was relatively uniformly distributed, supporting the findings of an earlier study on an apatite from Africa. The micro-XRFS at beam-line 2-ID-D of the APS can be reconfigured to increase the sensitivity at least 10-fold, which may allow the distribution of Cd and its elemental associations to be mapped in particles of most agricultural soils and facilitate other spectroscopic investigations. © 2007, CSIRO Publishing
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    Sol-gel microspheres and nanospheres for controlled release applications
    (Australian Nuclear Science and Technology Organisation, 2002-04-29) Barbé, CJ; Beyer, R; Kong, L; Blackford, MG; Trautman, RL; Bartlett, JR
    We present a novel approach to the synthesis of inorganic sol-gel microspheres for encapsulating organic and bioactive molecules, and controlling their subsequent release kinetics.The bioactive species are incorporated, at ambient temperature, into the inorganic particles using an emulsion gelation process, Independent control of the release rate (by adapting the nanostructure of the internal pore network to the physico-chemical properties of the bioactive molecules) and particle size (by tailoring the emulsion chemistry) is demonstrated.