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  1. Wo, Yii Mei, Hidayah Shahar, Zaharudin Ahmad
    MyJurnal
    Present of 241Am in the environment is being determined as part of surveillance and research
    programs related to nuclear activities. The separation of 241Am from environmental samples was
    carried out against the IAEA’s reference material by using an improved in-house radiochemical
    separation method through anion exchange column, followed by the electro-deposition on a
    stainless steel disc, and finally assayed on alpha spectrometry counting system. The resulting
    spectra showed good isolated peak, indicating a good separation of the radionuclide of interest.
    The analytical results were in good agreement with the certified value for IAEA-326 and IAEA-368
    with the calculated U-score was 0.36 and 0.82, respectively, showing no significant difference
    between the experimental and certified value. Using this method, distributions of 241Am in seabed
    surface sediment in the Exclusive Economic Zone of East Coast Peninsular Malaysia were studied.
    Samples were collected during June 2008 where the concentrations of 241Am were found to be
    ranged from < 0.08 to 0.36 Bq/kg, dry weight.
    Matched MeSH terms: Radiochemistry
  2. Zal U’yun Wan Mahmood, Norfaizal Mohamed @ Mohamad, Nik Azlin Nik Ariffin, Abdul Kadir Ishak
    MyJurnal
    An improved laboratory technique for measurement of polonium-210(
    210Po) in environmental
    samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian
    Nuclear Agency. To further improve this technique, a study with the objectives to determine the
    optimum conditions for
    210Po deposition and; evaluate the accuracy and precision results for
    the determination of 2 1 0 P o in environmental samples was carried-out. Polonium-210 which
    is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples
    has been efficiently plated onto one side of the silver disc in the spontaneous plating process for
    measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved
    using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl
    ammonium chloride and the plating temperature at 90
    oC. The plating was carried out in 80 mL
    HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 2 0 9 P o tracers in
    the CRM IAEA-385 and environmental samples were 85% – 98% whereby the efficiency of the
    new technique is a distinct advantage over the existing techniques. Therefore, optimization of
    deposition parameters is a prime importance to achieve accuracy and precision results as well as
    economy and time saving
    Matched MeSH terms: Radiochemistry
  3. Nurrul Assyikeen Md. Jaffary, Wo, Yii Mei, Abdul Kadir Ishak, Noor Fadzilah Yusof, Kamarozaman Ishak, Maziah Mahmud, et al.
    MyJurnal
    On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima,
    Japan which caused radioactive materials been released into the atmosphere in the form of
    aerosols and dust particles. Sea water around the plant was also found contaminated with high
    radioactivity readings. These radioactive materials could be transported by the winds and ocean
    current across international borders and cannot be controlled by human. Thus, a continuous
    monitoring activity of radionuclide content in the air and sea water needs to be conducted by the
    authorities. In addition to radioactivity monitoring, Malaysia should also control the entry of
    contaminated food in order to prevent radionuclide ingestion by human. The radionuclide 131I,
    134Cs and 137Cs were used as a measure of pollution levels and counted with gamma spectrometry
    using standard analysis method suggested by AOAC International. In this paper, details description
    of the role of Radiochemical and Environment Group, Nuclear Malaysia who’s responsible in
    analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was
    included. The radioactivity limit adopted and analysis results from this monitoring were discussed
    Matched MeSH terms: Radiochemistry
  4. Roselt P, Cullinane C, Noonan W, Elsaidi H, Eu P, Wiebe LI
    Molecules, 2020 Dec 03;25(23).
    PMID: 33287202 DOI: 10.3390/molecules25235700
    Vitamin E, a natural antioxidant, is of interest to scientists, health care pundits and faddists; its nutritional and biomedical attributes may be validated, anecdotal or fantasy. Vitamin E is a mixture of tocopherols (TPs) and tocotrienols (T-3s), each class having four substitutional isomers (α-, β-, γ-, δ-). Vitamin E analogues attain only low concentrations in most tissues, necessitating exacting invasive techniques for analytical research. Quantitative positron emission tomography (PET) with an F-18-labeled molecular probe would expedite access to Vitamin E's biodistributions and pharmacokinetics via non-invasive temporal imaging. (R)-6-(3-[18F]Fluoropropoxy)-2,7,8-trimethyl-2-(4,8,12-trimethyltrideca-3,7,11-trien-1-yl)-chromane ([18F]F-γ-T-3) was prepared for this purpose. [18F]F-γ-T-3 was synthesized from γ-T-3 in two steps: (i) 1,3-di-O-tosylpropane was introduced at C6-O to form TsO-γ-T-3, and (ii) reaction of this tosylate with [18F]fluoride in DMF/K222. Non-radioactive F-γ-T-3 was synthesized by reaction of γ-T-3 with 3-fluoropropyl methanesulfonate. [18F]F-γ-T-3 biodistribution in a murine tumor model was imaged using a small-animal PET scanner. F-γ-T-3 was prepared in 61% chemical yield. [18F]F-γ-T-3 was synthesized in acceptable radiochemical yield (RCY 12%) with high radiochemical purity (>99% RCP) in 45 min. Preliminary F-18 PET images in mice showed upper abdominal accumulation with evidence of renal clearance, only low concentrations in the thorax (lung/heart) and head, and rapid clearance from blood. [18F]F-γ-T-3 shows promise as an F-18 PET tracer for detailed in vivo studies of Vitamin E. The labeling procedure provides acceptable RCY, high RCP and pertinence to all eight Vitamin E analogues.
    Matched MeSH terms: Radiochemistry/methods
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