Qualitative and quantitative analysis of samples require good judgment from the analysts. These two aspects in gamma spectrometric analysis of Proficiency Test and solid radioactive waste samples for the determination of radionuclides are discussed. It is vital to judge and decide what energy peaks belong to which radionuclides prior to the creation of customized radionuclide library for the analysis of specific samples. Corrections due to radionuclide decay and growth, and the half-life assigned to a particular radionuclide in the uranium and thorium series are also discussed. Discussion on judgment to confirm the presence of thorium in food samples based on gamma spectrometry and neutron activation analysis is also provided.
Atmospheric Pollution due to airborne particle is a major concern to many cities in the Southeast Asian region, including Kuala Lumpur. Within the last six years air particulate samples have been collected from a site in Kuala Lumpur and measured for their PM10, PM2.5 and elemental concentrations. The results showed that the daily PM10 (
Assessment of source and sediment quality was carried out on marine sediments collected from the Tuanku Abdul Rahman National Park. Enrichment factors (EF), pollution load index (PLI) and geo-accumulation index (Igeo) were used to identify the sources of pollution, degree of contamination and sediment quality, respectively. Elemental analyses of marine sediment samples were performed by using the Instrumental Neutron Activation Analysis (INAA). Results from the Tunku Abdul Rahman National Park of Sabah indicated that most of the elements are considered to be from lithological or natural origin with EF values of less than 2 except for As (10 stations), Cr (3 stations), Lu (5 stations), Mg (2 stations), Sb (6 stations) and U (3 stations). For the sediment quality, most of the study area can be categorised as unpolluted for most of the elements (Igeo value < 2) except for As, Cr, Lu, Mg, Sb and U. A few study areas were slightly low contaminated with As, Cr, Lu, Mg, Sb and U. The contamination of As, Cr, Lu, Mg, Sb and U in the study area can be categorised as moderate with Igeo values ranged from 1 to 2. Meanwhile, the results of PLI value for sediment were ranged from 0.93 to 1.47 (PLI < 50) indicating there are not required to perform drastic rectification measures for the screening of the elements in the Tunku Abdul Rahman Park. Overall, assessment of the sediment quality at the Tunku Abdul Rahman National Park showed a few elements such as As, Cr, Lu, Mg, Sb and U were slightly enriched while most of the elements were similar to background values.
Chemical composition of fine (PM2.5) aerosol samples collected for the 5 years period (2001- 2005) using Gent Stacked filter unit sampler at Klang Valley (3 o 10 ’ 30 ’’ N, 101 o 43 ’ 24 ’’ E) were analysed using Neutron Activation Analysis (NAA) and Proton Induced X-ray Emission (PIXE). Results of the study show that the major component of the fine aerosol was black carbon and sulfur with the mass concentration ranged from 4.4 - 6.7µg m -3 and 1.2 - 1.9µg m -3 , respectively. The total fine aerosol mass concentration were in the ranged of 25 - 31µg m -3 with the reconstructed mass was about 50% as relative to the gravimetric mass. Statistical method, factor analysis with varimax approach has been applied to the aerosol composition data for the fingerprint identification. The analysis produces five identified fingerprint represent soil, industry, motor vehicles/biomass burning and Pb and Zn sources. There is also an unidentified source that could be related to unknown industrial activities.
Over 114 countries in the world grow rice and more than 50 countries have an annual rice production of 100,000 tonnes or more. Asian farmers produce about 90% of the global total rice production. Generally, there are two most common varieties of rice; cultivated and hill rice. Nowadays a lot of agriculture land is contaminated with toxic elements owing to the use of sludge or municipal compost, pesticides, fertilizers and emissions from municipal waste incinerators, car exhausts, residues from metalliferous mines, and smelting industries. The distribution and concentration of several toxic elements in grains particularly rice has lately become a big concern. A study to determine the concentrations of some elements in a few varieties of rice in our local market using Instrumental Neutron Activation Analysis has been performed by Waste and Environmental Technology Division, Malaysian Nuclear Agency. A total of 15 elements were measured. The method was validated by analysing the Standard Reference Material SRM-1568a (Rice Flour) and SRM-1573a (Tomato Leaves) of NIST. The measured concentrations of major and minor elements were analysed in terms of the average intake of nutrient content and comparison of several toxic elements to other studied values.
Stable isotope analysis has widely been used to trace the origin of organic materials in various fields, such as geochemistry, biochemistry, archeology and petroleum. In past a decade, it has also become an important tool for food traceability study. The globalisation of food markets and the relative ease which food commodities are transported through and between countries and continentsmeans that consumers are increasingly concerned about the origin of the foods they eat. The natural abundance of stable isotope variation such as carbon, nitrogen, hydrogen and oxygen are usedas geographic tracersor marker to determine the geographic origin of fruits, crop, vegetables and food products from animal. The isotopic compositions of plant materials reflect various factors such as isotopic compositions of source materials and their assimilation processes as well as growth environments. This paper will discuss on stable carbon and nitrogen isotopic compositions inricethat been determined by Isotope Ratio Mass Spectromety, advantages, limitations and potential of other analysis applicationsthat can be incorporated in food traceability system.