The content of the trace elements As, Br, Co, Cr, Fe, Hg, Sb and Zn has been evaluated in hair samples from selected population groups within Malaysia. Each population group was formed of individuals selected to be representative of the adult population living in a well-defined community. The groups were chosen from distinct regions with different socio-economical living habits in order to detect variability of the trace element burden among Malaysian. All the measurements were performed by means of instrumental neutron activation analysis after the hair samples were carefully washed according to standard procedures. The results for all elements investigated do not differ significantly from reported values for other regions of the world. The levels of As, Hg, and Sb are significantly different for the various groups and is strongly linked to local environmental factors.
The use of thek0-standardization method in instrumental neutron activation analysis gives good accuracy and precision. The analysis time can
be reduced drastically by employing software for thek0-standardization calculations. In this work samples were irradiated in a TRIGA reactor and the gamma spectrum was analysed
by Sampo 90 and thek0-standardization by the KAYZERO/SOLCOI code (DSM Research). The efficiency measurement and the peak to total ratio at the
reference and other geometries were measured and tested for their accuracy by analysing some reference materials. Reference
materials such as SRM 1572 (Citrus leaves), SRM 1573 (Tomato leaves), SRM 1575 (Pine needles), IAEA Soil-7 (Soil) and SRM
1646 (Estuarine sediment) were analysed for the major, minor and trace element contents. The results were in good agreement
with the certified or literature values. The recently released IAEA 140 (Sea plant homogenates) was also analysed for 28 elements.
A method was developed for the preconcentration and separation of trace manganese from natural water samples by complexation
with dithiocarbamate followed by adsorption onto C18-solid phase extraction column prior to irradiation. The Mn recovery was better than 99.8% without inteference from iron(III)
at 5 mg.l-1, copper(II), zinc(II), aluminum(III) and cobalt(II) at 0.5 mg.l-1 and sodium(I), potassium(I), magnesium(II) and calcium(II) at 1 mg.l-1. The separation factor was 100 and the detection limit was 0.01 μg.l-1 with good precision and accuracy with a relative error lower than 3%. The method was applied to the determination of Mn in
tap, well, river and treated water samples.
Results of inter-comparison test organized by the IAEA are analyzed according to the contribution and performance of INAA
as non-destructive method for trace elements analysis as compared to other techniques. Several methods were employed for certifying
the biological sample (IAEA-0140) and were also compared. It is shown that NAA is the method of a good accuracy and precision.
The biological sample has been investigated by INAA based on semi-absolute technique. More than 30 elements have determined
without using standards. The reference materials, which are certified in this manner and utilized as primary standard, are
The thermal to epithermal neutron flux ratio (f or Øth/Øe), epithermal neutron flux shape factor (α) and comparator factor (Fc) are essential parameters when calculating the concentration of sample using k0-standardization method in the neutron activation analysis (NAA). The work was performed in the Triga Mark II reactor of Malaysian
Institute for Nuclear Technology Research (MINT) using Au/Zr monitor couple. Twenty channels in the reactor have been evaluated
and the corresponding thermal to epithermal neutron flux ratios (f) ranged from 11.69 to 47.89. The epithermal neutron flux shape factors (α) were found in the range of −1.50·10−1 to 1.59·10−1 and the comparator factors (Fc) were calculated within the range of 9.85·103 to 6.70·104. These results allowed us to study the neutron flux distribution more precisely and established the goodness of fit for k0-NAA.
Authors:S. Rahman, A. Wood, S. Sarmani and A. Majid
The contents of mercury and organic mercury in various types of seafood from various location in Malaysia were determined by neutron activation analysis. Total mercury was determined by instrumental neutron activation analysis (INAA) whilst organic mercury was determined by INAA after chemical separation. Samples were digested in acid media and into the solution was added copper ion and KBr to release organic mercury compound from sulphur component of the tissue. The organic mercury was then extracted into toluene and then treated with cysteine paper to convert the compound into sub-organo-mercury from. The paper was then transferred into polyethylene vials and irradiated in the MINT TRIGA Reactor. Analytical results of organic mercury in Indian mackerel (Rastrelliger kanagurta), Spanish mackerel (Scomberomurus commersoni), shrimp (Peneaus sp.), squid (Loligo sp.) and cockle (Anadara granosa) is in the range of 45%–94% of the total mercury.
Authors:A. Majid, S. Sarmani, N. Yusoff, Y. Wei and F. Hamzah
Elemental content of twenty medicinal plants used as tonic and for treatment of diabetes and simusitis were determined by INAA and XRF. Elemental determination was carried out in the raw samples, residues after boiling and the water soluble fractions. Samples were irradiated in TRIGA MkII reactor and counted using HPGe detector coupled to Personal Computer Analyzer (PCA) system. Bowen's Kale, NBS Pine Needles, NBS Citrus Leaves SRM were analysed to check the accuracy of the techniques used. Twenty elements were determined by both NAA and XRF. Arsenic was only detected inLabisia pothoina andDracontomelon dao with a concentrations of 0.40 mg/kg and 0.60 mg/kg respectively. Antimony was found in eleven samples with a concentration of <0.20 mg/kg. Al, Br, Ca, Cl, K, Mn, Na and Rb were detected in all samples whereas Mg and Zn were present in all samples exceptCinnamomum sp. Highest concentration of Br (190 mg/kg), Cl (11805 mg/kg), Co (0.50 mg/kg), Fe (1642 mg/kg), K (36788 mg/kg), Mn (325 mg/kg), Na (126 mg/kg), Rb (197 mg/kg), Sc (0.18 mg/kg) and Zn (3551 mg/kg) were observed in the tuber ofLasia aculeata. Less than 70% and 50% of the elements contained inCallicarpa longifolia andEurycoma longifolia were obtained respectively from water by boiling.