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  • Author or Editor: S. Laoharojanaphand x
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Abstract  

Neutron activation analysis (NAA) methods were employed for the determination of total arsenic, and water soluble As(III) and As(V) compounds in freshwater fish/shellfish and plant samples from Southern Thailand. Total arsenic concentrations varied from 0.05 to 425 mg kg−1. Water soluble arsenic species were separated by solvent extraction using ammonium pyrrolidinedithiocarbamate (APDC)/methylisobutylketone (MIBK) followed by NAA. The water soluble As(III) and As(V) levels varied from 0.07 to 26.4 and 0.03 to 22.9 mg kg−1, respectively. The As(III) and As(V) detection limits were 0.007 for fish/shellfish, 0.005 for As(III) and 0.006 mg kg−1 for As(V) in plants. This separation method allows for the determination of water soluble As(III) and As(V) using commonly available and inexpensive laboratory equipment and chemicals, which can be coupled to a variety of quantification techniques.

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Abstract  

A pilot study was carried out to evaluate the scope of instrumental neutron activation analysis (INAA) for measuring the levels of selected elements in a few commonly consumed food items in Thailand. Several varieties of rice, beans, aquatic food items, vegetables and soybean products were bought from major distribution centers in Bangkok, Thailand. Samples were prepared according to the protocols prescribed by the nutritionist for food compositional analysis. Levels of As, Br, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, and Zn were measured by INAA using the irradiation and counting facilities available at the Thai Research Reactor with the maximum in-core thermal neutron flux of 3 × 1013 cm−2 s−1 of the Thailand Institute of Nuclear Technology in Bangkok. Selenium was determined by cyclic INAA using the Dalhousie University SLOWPOKE-2 Reactor facilities in Halifax, Canada at a thermal neutron flux of 2.5 × 1011 cm−2 s−1. Both cooked and uncooked foods were analyzed. The elemental composition of food products was found to depend significantly on the raw material as well as the preparation technique.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Laoharojanaphand
,
A. Busamongkol
,
S. Chaiyasith
,
V. Permnamtip
,
M. Parengam
, and
S. Srianujata

Abstract  

The nutrient value of Thai rice and bean in terms of minor and trace element content has been evaluated using INAA. Six varieties of rice and six of beans bought from three local markets in 2006–2007 were investigated under this study. Elemental compositions were determined using the comparator technique. Precision, accuracy and detection limits of each element found were also calculated. Three minor (Ca, K, Mg) and eight trace elements (Al, As, Br, Cl, Cu, Fe, Mn, Zn) were determined in these Thai foods.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Laoharojanaphand
,
W. Dharmavanij
,
A. Busamongkol
,
R. Pareepart
,
W. Wimolwattanapun
, and
W. Chantarachot

Abstract  

Research and development in activation analysis at the Thailand Institute of Nuclear Technology has been carried out over 40 years. The main activation source is from the TRIGA type research reactor TRR1/M1. Average in-core flux is around 1013 n·cm−2·s−1. Experience on the analysis of various kind of samples range from environmental field especially air particulate, ores, rocks and soil for natural resources exploration as well as industrial applications. Elemental composition in silk thread, silk cocoon and silk products from the royal silk project are one of the research work done incorporation with the Queen Sirikit Institute of Sericulture. Food items are also another topic of interest to our research team.

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