Testing the applicability of the k(o)-NAA method at the MINT's TRIGA MARK II reactor

The Analytical Chemistry Laboratory at MINT is using the NAA technique since 1980s and is the only laboratory in Malaysia equipped with a research reactor, namely the TRIGA MARK II. Throughout the years the development of NAA technique has been very encouraging and was made applicable to a wide range of samples. At present, the k0 method has become the preferred standardization method of NAA (k0-NAA) due to its multi-elemental analysis capability without using standards. Additionally, the k0 method describes NAA in physically and mathematically understandable definitions and is very suitable for computer evaluation. Eventually, the k0-NAA method has been adopted by MINT in 2003, in collaboration with the Nuclear Research Institute (NRI), Vietnam. The reactor neutron parameters (a and f) for the pneumatic transfer system and for the rotary rack at various locations, as well as the detector efficiencies were determined. After calibration of the reactor and the detectors, the implemented k0 method was validated by analyzing some certified reference materials (including IAEA Soil 7, NIST 1633a, NIST 1632c, NIST 1646a and IAEA 140/TM). The analysis results of the CRMs showed an average u score well below the threshold value of 2 with a precision of better than 710% for most of the elemental concentrations obtained, validating herewith the introduction of the k0-NAA method at the MINT

Assessment of Elemental Pollution in Marine Sediment from Talang-Satang and Bako National Park of Sarawak, Malaysia (Special Issue> Malaysian Nuclear Agency)

The assessments ofelemental polluti oinn sediment collected from national park ofSarawak were done based on their distribution pattern ,geoaccumulation index and enrichment factor ,The enrichment factor s(EF )were determined by the elemental rationing method, whilst the geoaccumulati oinndex (Ig .by. )comparing of current concentration to background concentration of metals, The elements were analyzed by using Instmmenta1 Neutron Activatio nAnalysis (INAA) .The results of enrichment facto rshow tha tTalang-Satang and Bako National Park have significant contaminated by toxic elements such as As, Cr, Sb, Ti and U. Base on the classification system proposed for sediment qualit ywith referring to Ig. ,the sediment quali tyof the Talang-Satang and Bako National Park for Arsenic (As) contamination can be categorized as moderate to extremely contaminated. Contamination of element such as Cr, Sb and Ti can be categorized as uncontaminated to moderate contaminated, and U can be categorized as uncontaminated to moderate and strong contaminated, The average concentration of As in sediment of Bako shown surpassed sediment qualit yguidelin eCprobable effect concentration - PEC) value, whilst Cr concentration in sediment of Talang-Satang shown above midpoint effect concentration (MEC) .This indicatin gt,he sediment ofBako and Talang-Satang could have a potentia lfor producing chronic effect to the marine biot aor benthi ocrganism

Polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of East Coast Peninsular Malaysia

The polycyclic aromatic hydrocarbons (PAHs) are pollutants of concern due to their persistent in the marine ecosystem, thus its can cause long-term adverse effect to the marine life. In this study the concentrations of PAHs in east coast Peninsular Malaysia sediments were determined. About ten stations along the east coast of the coastal area were selected to collect sediment samples using grab sampler. The PAHs from the sediment samples were soxhlet extracted using mixture of hexane and dichloromethane (DCM). Fractionation was done using the silica-alumina column. About 17 compounds of the PAHs were determined using the Gas Chromatography-Mass Spectrometer (GCMS model QP5050A). The Σ PAHs was found in range between 0.26μg/g to 0.59μg/g dry weight. The data from the study signified that the main source of PAHs in the sediment of the east coast peninsular Malaysia is originated from the pyrolytic source

Parameterisation of fission neutron spectra (TRIGA Reactor) for neutron activation without the used of standard

Neutron activation analysis (NAA) is a sensitive and reliable technique for both qualitative and quantitative analysis of wide range of elements in various types of samples. The method involves the irradiation of samples and the detection of gamma energies emitted from the isotope s for med from the process of neutron capture. Most NAA were done by comparison method, which is found to have high errors due to the differences in the matrix composition of sample as well a s comparator. The purpose of this study is to demonstrate an alternative technique of activation analysis based on absolute gammarray measurem ents and the direct calculation of elemental concentrations from reaction rates equation of neutron capture process

Determination of heavy metal pollution in depth profile of marine sediment samples from the Strait of Malacca

In this study, four core marine sediment samples from the Strait of Malacca were collected and analyzed by using instrumental neutron activation analysis (INAA). This work was carried out to evaluate the level of heavy metal pollution in the water-body. In addition, inductively coupled plasma-mass spectroscopy (ICP-MS) technique was used for non-measurable elements by INAA. The following heavy metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb and Zn) have been determined in the core sediment samples collected from the Strait of Malacca. Moreover, the obtained results were compared to the national studies and the international guidelines for marine sediments