Applications of neutron activation analysis
The following examples are a small selection of the potential applications of NAA.
A researcher in photovoltaics wants to confirm that gold doping of silicon wafers was as expected. The very high sensitivity of NAA to gold and the insensitivity to Si means that concentrations down to ppb can be accurately measured.
The accuracy, precision and multi-element capabilities of NAA allows researchers to fingerprint ochre samples from different sites around Australia using multivariate statistics. The resulting database provides insights into the movement, trade and uses of ochre by Aboriginal peoples.
A short irradiation of meteorite chondrules weighing around 2 mg is sufficient for NAA to quantify the major constituents. Because NAA is non-destructive, the chondrules can be returned to the researchers after one month, allowing additional analyses to be performed.
An iron ore mining company wants to produce reference materials for internal QA/QC. The accuracy of NAA and its ability to quantify ‘difficult’ elements, such as chlorine, is highly valued. NAA provides data that can be used to check alternative analytical methods.
Trace element analysis of food products are required to confirm their safety and establish their region of origin. NAA’s sensitivity, multi-element capability and ease of sample preparation offer particular advantages for this application.
The level of heavy metals such as arsenic in hair and nails may indicate industrial or environmental exposure to toxins. The ability of NAA to measure small samples ‘as collected’ and the freedom from analytical blanks make it a powerful tool for epidemiological studies.