Curtain comes down on gold theft

Trading in stolen gold just became a little harder thanks to the work of a researcher at Western Australia's Curtin University. His work in gold fingerprinting is helping stop the black market exchange of gold.

Every piece of gold has a unique trace metal element make-up, making it possible to identify the origin of each piece of gold that is refined. The metal make-up of gold is often referred to as its 'fingerprint', with each gold fingerprint as individual to a piece of gold as a fingerprint is to a person.

Scientists with an interest in forensic pursuits, such as Associate Professor John Watling and his colleague, Allen Thomas from Curtin University's School of Applied Chemistry, have refined the process of gold fingerprinting using an inductively coupled plasma mass spectrometer (ICP-MS).

The pair have been able to improve gold fingerprinting to the point that Australian police are now able to use the technique to identify the origin of stolen gold.

Gold has often been favoured over money as payment in drug circles, as previously it could not be easily traced. It is suggested that anywhere between $20 and $100 million worth of gold is stolen in Australia alone each year.

In an effort to combat these escalating figures, the recently established John de Laeter Centre of Mass Spectrometry at Curtin University is helping Watling and Thomas in their research.

Features of the ICP-MS in operation at the centre include a TJA (VG/Fisons) PlasmaQuad 3 Quadrupole ICP-MS. The system has a high sensitivity interface to facilitate ultra-low detection limits and a TJA (VG/Fisons) Laserlab high resolution 266 nm (frequency quadrupled Nd-YAG) laser. The laser system is adapted with a high-resolution interface to facilitate the ablation of craters down to 10 µm in diameter. GBC Optimas 8000 time of flight ICP-MS, Leco Renaissance time of flight ICP-MS, and a wide range of chromatographic and thermal dissociation interfacing is also available.

The ICP-MS's laser ablation, graphite furnace, liquid and gas chromatographic interfacing has facilitated the analysis of a significantly increased variety of sample types, enabling the determination of up to 60 elements in samples as small as 10 µm in diameter. It has also improved the resolution and detection limits of organo-metallic species analysis in such matrices as foodstuffs, water, sediment and environmental samples.

Commercial enterprise has found that geochemical analyses by plasma-atomic emission spectrometry (ICP-AES) and ICP-MS methods are much more efficient in fingerprinting deposits and formations than when using atomic absorption spectrophotometry (AAS).

Further to the centre's ICP-MS, the Advanced Ultra-Clean Environment (ACE) Facility and the Sensitive High Resolution Ion MicroProbe (SHRIMP) allow research into areas including geochronology, climate change and pollution studies, forensic science, chemical metrology and extra-terrestrial research.

This range of research requires a cold, perfectly clean environment to enhance the capacity of sensitive modern instrumentation and advanced techniques used by the centre and its collaborators.

The ACE facility provides the ability to prepare samples free from contamination, while the SHRIMP allows in situ isotopic analysis of chemically complex materials with a spatial resolution of five to 20 µm.

In order to make the centre's work worthwhile, there must be some concerted effort to make gold fingerprinting an option in forensic applications on a global scale. Watling explained on ABC radio: "We are trying to co-ordinate and consolidate all that information and knowledge and bring it together under one roof, so that there is an international database for gold fingerprinting and for other things like diamonds and drugs which we also do fingerprinting on."

An international database would allow police and researchers such as Watling to store and access information about gold fingerprints from around the globe.

Currently, the technique of fingerprinting is being used around the world, with many groups constructing their own databases to keep track of their gold resources. The shortfall being that the databases are not all maintained as one. Director of Member Services for the Chamber of Minerals and Energy, Reg Howard-Smith told the ABC: "Logistics is certainly an issue, security of the database is a significant issue, as is acceptability as evidence in courts of law. Economics are also a consideration in any review of the concept and I think potentially it could be a tool that could be useful for marketing."

Such teething problems are always expected at the beginning of new innovations, but this hasn't deterred Watling from trumpeting the benefits of gold fingerprinting in the hope that support for the tool will survive the initial establishment problems.

Watling sells the financial benefits of fingerprinting in a bid to gain support from those it benefits most and who could provide the greatest financial support to furthering his research. "The application (gold fingerprinting) is to cut down gold theft at the source, and improve the profitability of mines," Watling told the ABC.

A problem in many mines is a lack of hard documentation of every piece of gold that is recovered. This is often due to the vast size of many mines. This is a line Watling plays in his attempt to gain support. "Don't forget, if you steal a million dollars from one particular mine it isn't a percentage stealing, it's actually a million dollars total profit gone, because that has never been recorded on your books. So it really is hard cash that has gone."

Mines are not the only areas that could benefit from gold fingerprinting. Criminal investigation processes could benefit greatly by the advancing technology, and with gold such an important payment method in international drug rings, the contribution to lowering the level of drugs being exchanged around the world could be great. An increase of support for Watling and his colleagues' work could ensure a golden future for fingerprinting and a growing thorn in the side of drug circles around the world.